MedWorm: Dengue Fever

[Correspondence] Call for a World Dengue Day

LANCET — Sat, 04 Feb 2012 05:00:00 +0100

Dengue fever is a mosquito-borne disease caused by dengue viruses—members of the family Flaviviridae. Severe forms of dengue infection can be fatal and are a leading cause of hospital admission in many parts of the world, placing tremendous pressure on medical resources and having a heavy economic and societal effect. There has been a 30-fold increase in the number of dengue cases over the past 50 years. Recent studies estimate 50–100 million infections each year, although, owing to under-reporting, this figure could be even higher. (Source: LANCET)

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Brazil Deploys "Junior Firefighters" to Snuff Out Dengue

IPS Inter Press Service - Health — Fri, 03 Feb 2012 12:18:13 +0100

The government of the state of Rio de Janeiro is unveiling a battery of creative tactics to engage the population in the battle against dengue fever, which is threatening to reach unprecedented epidemic proportions as a new virus strain hits Brazil. (Source: IPS Inter Press Service - Health)

Dengue fever down 36 per cent in Thailand after floods

Monsters and Critics Health News — Fri, 03 Feb 2012 09:23:01 +0100

(Source: Monsters and Critics Health News)

Hypocalcemic Tetany: An Infrequently Recognized Association with Acute Dengue Infection

Indian Journal of Pediatrics — Thu, 02 Feb 2012 18:10:35 +0100

Content Type Journal ArticleCategory Scientific Letter to the EditorPages 1-1DOI 10.1007/s12098-012-0690-3Authors Seema Kapoor, Department of Pediatrics, Maulana Azad Medical College, New Delhi, IndiaAnkur Singh, Department of Pediatrics, Maulana Azad Medical College, New Delhi, India Journal Indian Journal of PediatricsOnline ISSN 0973-7693Print ISSN 0019-5456 (Source: Indian Journal of Pediatrics)

A Three-Component Biomarker Panel for Prediction of Dengue Hemorrhagic Fever.

The American Journal of Tropical Medicine and Hygiene — Wed, 01 Feb 2012 05:00:00 +0100

Authors: Brasier AR, Ju H, Garcia J, Spratt HM, Victor SS, Forshey BM, Halsey ES, Comach G, Sierra G, Blair PJ, Rocha C, Morrison AC, Scott TW, Bazan I, Kochel TJ, The Venezuelan Dengue Fever Working Group Abstract Abstract. Dengue virus infections are a major cause of morbidity in tropical countries. Early detection of dengue hemorrhagic fever (DHF) may help identify individuals that would benefit from intensive therapy. Predictive modeling was performed using 11 laboratory values of 51 individuals (38 DF and 13 DHF) obtained on initial presentation using logistic regression. We produced a robust model with an area under the curve of 0.9615 that retained IL-10 levels, platelets, and lymphocytes as the major predictive features. A classification and regression tree was developed o...

Molecular detection and typing of dengue viruses from archived tissues of fatal cases by rt-PCR and sequencing: diagnostic and epidemiologic implications.

The American Journal of Tropical Medicine and Hygiene — Wed, 01 Feb 2012 05:00:00 +0100

Authors: Bhatnagar J, Blau DM, Shieh WJ, Paddock CD, Drew C, Liu L, Jones T, Patel M, Zaki SR Abstract Abstract. Diagnosis of dengue virus (DENV) infection in fatal cases is challenging because of the frequent unavailability of blood or fresh tissues. For formalin-fixed, paraffin-embedded (FFPE) tissues immunohistochemistry (IHC) can be used; however, it may not be as sensitive and serotyping is not possible. The application of reverse transcription-polymerase chain reaction (RT-PCR) for the detection of DENV in FFPE tissues has been very limited. We evaluated FFPE autopsy tissues of 122 patients with suspected DENV infection by flavivirus and DENV RT-PCR, sequencing, and DENV IHC. The DENV was detected in 61 (50%) cases by RT-PCR or IHC. The RT-PCR and sequencing detected DENV in ...

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Factors associated with dengue mortality in latin america and the Caribbean, 1995-2009: an ecological study.

The American Journal of Tropical Medicine and Hygiene — Wed, 01 Feb 2012 05:00:00 +0100

In this study, we aimed to estimate the effect that environmental, demographic, and socioeconomic factors have on dengue mortality in Latin America and the Caribbean. To that end, we conducted an observational ecological study, analyzing data collected between 1995 and 2009. Dengue mortality rates were highest in the Caribbean (Spanish-speaking and non-Spanish-speaking). Multivariate analysis through Poisson regression revealed that the following factors were independently associated with dengue mortality: time since identification of endemicity (adjusted rate ratio [aRR] = 3.2 [for each 10 years]); annual rainfall (aRR = 1.5 [for each 10(3) L/m(2)]); population density (aRR = 2.1 and 3.2 for 20-120 inhabitants/km(2) and > 120 inhabitants/km(2), respectively); Human Development Index &g...

Infectious Etiologies of Acute Febrile Illness among Patients Seeking Health Care in South-Central Cambodia.

The American Journal of Tropical Medicine and Hygiene — Wed, 01 Feb 2012 05:00:00 +0100

Authors: Kasper MR, Blair PJ, Touch S, Sokhal B, Yasuda CY, Williams M, Richards AL, Burgess TH, Wierzba TF, Putnam SD Abstract Abstract. The agents of human febrile illness can vary by region and country suggesting that diagnosis, treatment, and control programs need to be based on a methodical evaluation of area-specific etiologies. From December 2006 to December 2009, 9,997 individuals presenting with acute febrile illness at nine health care clinics in south-central Cambodia were enrolled in a study to elucidate the etiologies. Upon enrollment, respiratory specimens, whole blood, and serum were collected. Testing was performed for viral, bacterial, and parasitic pathogens. Etiologies were identified in 38.0% of patients. Influenza was the most frequent pathogen, followed by den...

Delayed diagnosis of systemic lupus erythematosus due to misinterpretation of dengue serology.

Scandinavian Journal of Rheumatology — Wed, 01 Feb 2012 05:00:00 +0100

Authors: Santosa A, Poh Z, Teng G PMID: 22283727 [PubMed - in process] (Source: Scandinavian Journal of Rheumatology)

The Importance of Accurate Diagnosis of Dengue FeverThe Importance of Accurate Diagnosis of Dengue Fever

Medscape Today Headlines — Mon, 30 Jan 2012 04:00:00 +0100

Early diagnosis and prompt treatment is very important in dengue fever. How can we avoid diagnostic errors? Future Virology (Source: Medscape Today Headlines)

Dengue threatens 2.5 billion people

Health News - UPI.com — Thu, 26 Jan 2012 05:28:18 +0100

GENEVA, Switzerland, Jan. 25 (UPI) -- Dengue, a mosquito-borne viral disease, threatens about 2.5 billion people -- more than 40 percent of the world's population -- a U.N. report said. (Source: Health News - UPI.com)

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Dengue fever threatens 2.5 billion people

Health News - UPI.com — Thu, 26 Jan 2012 05:28:18 +0100

GENEVA, Switzerland, Jan. 25 (UPI) -- Dengue fever, a mosquito-borne viral disease, threatens about 2.5 billion people -- more than 40 percent of the world's population -- a U.N. report said. (Source: Health News - UPI.com)

A local outbreak of dengue caused by an imported case in Dongguan China

BMC Public Health - Latest articles — Thu, 26 Jan 2012 05:00:00 +0100

Conclusions: Several characterized points of urbanization contributed to this outbreak of dengue in Dongguan: the residents are highly concentrated; the residents' life habits helped to form the habitats of Ae. albopictus and contributed to the high Breteau Index; the self-constructed houses lacks of mosquito prevention facilities. This report has reaffirmed the importance of a surveillance system for infectious diseases control and aroused the awareness of an imported case causing the epidemic of an infectious disease in urbanized region. (Source: BMC Public Health - Latest articles)

Aedes albopictus and the reemergence of Dengue

BMC Public Health - Latest articles — Tue, 24 Jan 2012 05:00:00 +0100

Dengue is a vector-borne disease that is estimated to affect millions of individuals each year in tropical and subtropical areas, and it is reemerging in areas that have been disease-free for relatively long periods of time. In this issue of the journal, Peng et al. report on a Dengue outbreak in a city in southern China that had been disease-free for more than two decades. The infection, which was due to serotype 1, was introduced by a traveler from South-east Asia and transmitted by Aedes albopictus, the Asian tiger mosquito. Compared to Aedes aegypti, which is the most important vector of Dengue, Ae albopictus is a less competent vector of arboviruses, and the epidemics it causes are milder. However, Ae albopictus is becoming an increasingly important vector because of its rapidly chang...

Identification of serotype specific T cell responses to highly conserved regions of the dengue viruses

Clinical and Experimental Immunology — Fri, 20 Jan 2012 11:18:15 +0100

SummaryDetermining the past infecting dengue virus (DENV) serotypes has been difficult due to highly cross‐reactive immune responses from previous DENV infections. Determining the correlates of serotype specific immune responses would be crucial in understanding dengue transmission in the community and would also help to determine the correlates of a protective immune responses. Therefore, we set out to define highly conserved, serotype specific regions of the DENVs.Serotype‐specific and highly conserved regions of the four DENV serotypes were identified using BLAST searches and custom perl scripts. Using ex vivo and cultured ELISpot assays we identified serotype specific T cell epitopes within the four DENV serotypes in healthy adult donors from Sri Lanka. We identified T cell respons...

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Evaluation of a novel commercial rapid test for dengue diagnosis based on specific IgA detection

Diagnostic Microbiology and Infectious Disease — Thu, 19 Jan 2012 03:02:10 +0100

Abstract: The performance of the novel commercial test ASSURE® Dengue IgA Rapid test (MP Diagnostics) was evaluated using a panel of 172 sera collected from dengue patients and 47 sera from healthy blood donors. The overall specificity and sensitivity were 61.0% and 85.1%, respectively. However, the positivity rate for IgA went from 33.3% for sera collected the same day of fever onset to 81.2% for sera collected 5 days after fever onset. Infections with serotype 2 viruses were detected more efficiently than those with serotype 1 viruses, and no sera from infections with serotypes 3 and 4 were available. In addition, the kit was twice more efficient at detecting secondary infections than at detecting primary infections. Finally, the ASSURE® test showed good repeatability and reproducibili...

Identification of a small-molecule inhibitor of dengue virus using a replicon system

Archives of Virology — Tue, 17 Jan 2012 07:12:29 +0100

Abstract Dengue virus (DENV) is a mosquito-borne human pathogen that causes a serious public-health threat in tropical and subtropical regions of the world. Neither a vaccine to prevent nor an effective therapeutic agent to treat DENV infection is currently available. We established a stable cell line harboring a luciferase-reporting DENV subgenomic replicon to screen for inhibitors of DENV. A total of 14,400 small-molecule (MW < 500 Da) chemicals were evaluated for their ability to reduce luciferase reporter activity in cell lysates. One effective compound was identified from the screening. This compound was found to reduce virus production but did not block virus entry in virus-based assay. Mode-of-action analysis revealed that this inhibitor suppressed ...

Neurological complications of dengue fever: Experience from a tertiary center of north India

Annals of Indian Academy of Neurology — Tue, 17 Jan 2012 05:00:00 +0100

Conclusion: Dengue fever was associated with widespread neurological complications. Brachial neuritis and opsoclonus-myoclonus syndrome were observed for the first time in this study. (Source: Annals of Indian Academy of Neurology)

Global Trends in the Use of Insecticides for Vector-borne Disease Control

EHP-in-Press — Tue, 17 Jan 2012 05:00:00 +0100

CONCLUSIONS: The global use of DDT has not changed substantially since the Stockholm Convention entered into force. The dominance of pyrethroid use has major implications due to the spread of insecticide resistance with potential to reduce the efficacy of LNs. Insecticide resistance management should be coordinated between disease-specific programs and sectors within the context of an integrated vector management approach. (Source: EHP-in-Press)

Epidemiology of dengue infections in Kassala, Eastern Sudan

Journal of Medical Virology — Mon, 16 Jan 2012 07:19:43 +0100

AbstractEighty‐one (71.7%) out of 113 patients had confirmed dengue infection (using ELISA IgM serology) at Kassala, Eastern Sudan during the period of August through November 2010. According to the WHO criteria, dengue fever (DF), dengue hemorrhagic fever (DHF), and dengue shock syndrome (DSS) were observed in 30.9, 58, and 11.1% of these patients, respectively. The mean age of these 81 patients was 25.5 years. Male:female ratio was 1.8:1. Various symptoms including fever (100%), headache (75.3%), vomiting (55.6%), nausea (53.1%), and backache (30.9%) were observed among these patients. Thrombocytopenia (<100/109 platelets/L), and leucopenia (WBC count <4,000 × 109 cells/L) and hemoconcentration (hematocrit >45) were reported in 86.4, 69.1, and 67.9% of the patients, respe...

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Nonstructural protein NS1 immunodominant epitope detected specifically in dengue virus infected material by a SELDI‐TOF/MS based assay

Journal of Medical Virology — Mon, 16 Jan 2012 07:19:42 +0100

In this study, the detection of NS1 protein in DV‐infected material was assessed by an alternative method combining a single NS1‐directed monoclonal antibody and the SELDI‐TOF/MS technology. According to the epitope mapping, the antibodies used are mainly directed against an immuno‐dominant peptide located on the C‐terminal part of the protein. The NS1 SELDI‐TOF assay is specific, has a sensitivity level close to capture‐ELISAs and is potentially useful for a coupled serotyping/detection assay or for the detection of subtle post‐translational modifications on the protein. J. Med. Virol. 84:490–499, 2012. © 2011 Wiley Periodicals, Inc. (Source: Journal of Medical Virology)

Study provides clues on severe dengue fever

SciDev.Net — Mon, 16 Jan 2012 00:14:34 +0100

A Nicaraguan study is helping scientists understand why a second dengue fever infection can be more severe than the first one. (Source: SciDev.Net)

Screening of anti-dengue activity in methanolic extracts of medicinal plants

BMC Complementary and Alternative Medicine — Fri, 13 Jan 2012 05:00:00 +0100

Conclusions, The methanol extracts of A. paniculata and M. charantia possess the ability of inhibiting the activity of DENV-1 in in vitro assays. Both of these plants are worth to be further investigated and might be advantageous as an alternative for dengue treatment. (Source: BMC Complementary and Alternative Medicine)

A West Nile virus CD4 T cell epitope improves the immunogenicity of dengue virus serotype 2 vaccines.

Virology — Fri, 13 Jan 2012 05:00:00 +0100

Authors: Hughes HR, Crill WD, Davis BS, Chang GJ Abstract Flaviviruses, such as dengue virus (DENV) and West Nile virus (WNV), are among the most prevalent human disease-causing arboviruses world-wide. As they continue to expand their geographic range, multivalent flavivirus vaccines may become an important public health tool. Here we describe the immune kinetics of WNV DNA vaccination and the identification of a CD4 epitope that increases heterologous flavivirus vaccine immunogenicity. Lethal WNV challenge two days post-vaccination resulted in 90% protection with complete protection by four days, and was temporally associated with a rapid influx of activated CD4 T cells. CD4 T cells from WNV vaccinated mice could be stimulated from epitopic regions in the envelope protein transmem...

Anti-GM Groups Attempt to Sully Transgenic Control of Dengue Fever

Scientific American Topic - Medical Technology — Thu, 12 Jan 2012 19:00:00 +0100

Genetically engineered mosquitoes developed by British biotech firm Oxitec as an approach to controlling dengue fever have been caught up in controversy since 6,000 of them were deliberately released to an uninhabited forest in Malaysia in a trial in December 2010. [More] (Source: Scientific American Topic - Medical Technology)

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Testing the Effectiveness of Community-Based Dengue Vector Control Interventions Using Semiparametric Mixed Models

Vector-Borne and Zoonotic Diseases — Thu, 12 Jan 2012 13:54:51 +0100

Vector-Borne and Zoonotic Diseases , Vol. 0, No. 0. (Source: Vector-Borne and Zoonotic Diseases)

Novel Anti-Viral Immune Pathway Discovered In The Mosquito

Health News from Medical News Today — Thu, 12 Jan 2012 08:00:00 +0100

As mosquito-borne viral diseases like West Nile fever, dengue fever, and chikungunya fever spread rapidly around the globe, scientists at Virginia Tech are working to understand the mosquito's immune system and how the viral pathogens that cause these diseases are able to overcome it to be transmitted to human and animal hosts. In nearly every part of the world, humans and animals experience high levels of morbidity and mortality after being bitten by mosquitoes infected with viruses... (Source: Health News from Medical News Today)

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The clinical differences between dengue and scrub typhus with acute respiratory failure in southern Taiwan

Infection — Wed, 11 Jan 2012 17:53:01 +0100

Conclusions This study provides relatively rare data regarding the clinical differences between adult dengue and scrub typhus patients with ARF. Content Type Journal ArticleCategory Clinical and Epidemiological StudyPages 1-7DOI 10.1007/s15010-011-0239-9Authors H.-C. Chang, Division of Pulmonary and Critical Care Medicine, Department of Internal Medicine, Kaohsiung Chang Gung Memorial Hospital and Chang Gung University College of Medicine, No. 123, Dapi Road, Niaosong District, Kaohsiung, 83301 TaiwanM.-C. Lin, Division of Pulmonary and Critical Care Medicine, Department of Internal Medicine, Kaohsiung Chang Gung Memorial Hospital and Chang Gung University College of Medicine, No. 123, Dapi Road, Niaosong District, Kaohsiung, 83301 TaiwanS.-F. Liu, Division of Pulmon...

Researchers discover novel anti-viral immune pathway in the mosquito

EurekAlert! - Medicine and Health — Tue, 10 Jan 2012 05:00:00 +0100

(Virginia Tech) Virginia Tech researchers have identified a novel anti-viral pathway in the immune system of culicine mosquitoes, the insect family to which mosquitoes that spread yellow fever, West Nile fever, dengue fever, and chikungunya fever belong. (Source: EurekAlert! - Medicine and Health)

Prevalence of anti-dengue immunoglobulin G antibodies among American Red Cross blood donors in Puerto Rico, 2006.

Transfusion — Sun, 08 Jan 2012 05:00:00 +0100

CONCLUSION: Supplementary serologic testing of donated blood can potentially provide information on the silent circulation or introduction of dengue serotypes. PMID: 22224623 [PubMed - as supplied by publisher] (Source: Transfusion)

Positive selection sites in the surface genes of dengue virus: phylogenetic analysis of the interserotypic branches of the four serotypes

Virus Genes — Thu, 05 Jan 2012 17:00:59 +0100

Abstract The existence of four dengue serotypes is associated with a phenomenon called “Antibody-Dependent Enhancement” that has been suggested to cause a severe form of dengue hemorrhagic fever and shock syndrome. To study the evolutionary event that drove the serotype separation, we employed the maximum likelihood approach by focusing on the Premembrane (prM) and Envelop (E) genes. We showed that the separation of dengue serotypes had been dominantly under purifying selection. In spite of the strong selective constraint, one codon of prM gene and twelve codons of E gene were detected to be under positive selection. This indicates that the E protein might have been under a stronger positive pressure than the PrM protein. The codons under positive selection were identifi...

Current and future applications of dried blood spots in viral disease management.

Antiviral Research — Thu, 05 Jan 2012 05:00:00 +0100

In conclusion, DBS card sampling and storage will aid the adequate of outbreak management of existing and emerging viral diseases. PMID: 22244848 [PubMed - as supplied by publisher] (Source: Antiviral Research)

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Erratum to:Dengue virus-specific CD4+ and CD8+ T lymphocytes target NS1, NS3 and NS5 in infected Indian rhesus macaques

Immunogenetics — Wed, 04 Jan 2012 07:00:39 +0100

Content Type Journal ArticleCategory ErratumPages 1-2DOI 10.1007/s00251-011-0593-xAuthors Katherine M. Mladinich, Microbiology Doctoral Training Program, University of Wisconsin–Madison, 1326 Microbial Sciences, 1550 Linden Drive, Madison, WI 53706, USAShari M. Piaskowski, Department of Pathology and Laboratory Medicine, University of Wisconsin–Madison, 555 Science Dr, Madison, WI 53711, USARichard Rudersdorf, Department of Pathology and Laboratory Medicine, University of Wisconsin–Madison, 555 Science Dr, Madison, WI 53711, USAChristopher M. Eernisse, Department of Pathology and Laboratory Medicine, University of Wisconsin–Madison, 555 Science Dr, Madison, WI 53711, USAKim L. Weisgrau, Department of Pathology and Laboratory Medicine, University of Wisconsin–Madison, 555 Scie...

In This Issue [This Week in PNAS]

Proceedings of the National Academy of Sciences — Tue, 03 Jan 2012 05:00:00 +0100

Bacteria might help curb the spread of dengue viruspnas;109/1/1/UNFIG01F1unfig01Aedes albopictus mosquito feeding on human blood. Image courtesy of James Gathany/Centers for Disease Control and Prevention.The Asian tiger mosquito Aedes albopictus transmits the dengue virus across the tropics, with a range that has recently expanded across southern Europe and the Americas. Because tiger mosquitoes bite humans during the day, insecticide-treated mosquito nets are of little use in curbing the spread of dengue fever, for which there is no vaccine. Marcus Blagrove et al. (pp. 255–260) attempted to exploit bacteria that naturally infects insects as a means toward replacing wild populations with... (Source: Proceedings of the National Academy of Sciences)

Wolbachia induces reactive oxygen species (ROS)-dependent activation of the Toll pathway to control dengue virus in the mosquito Aedes aegypti [Microbiology]

Proceedings of the National Academy of Sciences — Tue, 03 Jan 2012 05:00:00 +0100

In this study, we have deciphered how Wolbachia infection affects the Aedes aegypti host in inducing resistance to DENV. The microarray assay indicates that transcripts of genes with functions related to immunity and reduction-oxidation (redox) reactions are up-regulated in Ae. aegypti infected with Wolbachia. Infection with this bacterium leads to induction of oxidative stress and an increased level of reactive oxygen species in its mosquito host. Reactive oxygen species elevation is linked to the activation of the Toll pathway, which is essential in mediating the expression of antioxidants to counterbalance oxidative stress. This immune pathway also is responsible for activation of antimicrobial peptides—defensins and cecropins. We provide evidence that these antimicrobial peptides are...

Wolbachia strain wMel induces cytoplasmic incompatibility and blocks dengue transmission in Aedes albopictus [Genetics]

Proceedings of the National Academy of Sciences — Tue, 03 Jan 2012 05:00:00 +0100

This study provides an example of strong pathogen inhibition in a naturally Wolbachia-infected mosquito species, demonstrating that this inhibition is not limited to naturally naïve species, and suggests that the Wolbachia strain is more important than host background for viral inhibition. Complete bidirectional cytoplasmic incompatibility was observed with WT strains infected with the naturally occurring Ae. albopictus Wolbachia, and this provides a mechanism for introducing wMel into natural populations of this species. (Source: Proceedings of the National Academy of Sciences)

Study Details How Dengue Infection Hits Harder The Second Time Around

Health News from Medical News Today — Mon, 02 Jan 2012 08:00:00 +0100

One of the most vexing challenges in the battle against dengue virus, a mosquito-borne virus responsible for 50-100 million infections every year, is that getting infected once can put people at greater risk for a more severe infection down the road. Now, for the first time, an international team of researchers that includes experts from the University of California, Berkeley, has pulled apart the mechanism behind changing dengue virus genetics and dynamics of host immunity, and they are reporting their findings in the Dec. 21 issue of Science Translational Medicine... (Source: Health News from Medical News Today)

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Chikungunya and Dengue Fever among Hospitalized Febrile Patients in Northern Tanzania.

The American Journal of Tropical Medicine and Hygiene — Sun, 01 Jan 2012 05:00:00 +0100

Authors: Hertz JT, Munishi OM, Ooi EE, Howe S, Lim WY, Chow A, Morrissey AB, Bartlett JA, Onyango JJ, Maro VP, Kinabo GD, Saganda W, Gubler DJ, Crump JA Abstract Abstract. Consecutive febrile admissions were enrolled at two hospitals in Moshi, Tanzania. Confirmed acute Chikungunya virus (CHIKV), Dengue virus (DENV), and flavivirus infection were defined as a positive polymerase chain reaction (PCR) result. Presumptive acute DENV infection was defined as a positive anti-DENV immunoglobulin M (IgM) enzyme-linked immunsorbent assay (ELISA) result, and prior flavivirus exposure was defined as a positive anti-DENV IgG ELISA result. Among 870 participants, PCR testing was performed on 700 (80.5%). Of these, 55 (7.9%) had confirmed acute CHIKV infection, whereas no participants had confir...

Evaluation of the 2009 WHO Dengue Case Classification in an Indonesian Pediatric Cohort.

The American Journal of Tropical Medicine and Hygiene — Sun, 01 Jan 2012 05:00:00 +0100

Authors: van de Weg CA, van Gorp EC, Supriatna M, Soemantri A, Osterhaus AD, Martina BE Abstract Abstract. The classification of dengue virus-infected patients continues to be a challenge to researchers and clinicians in the field. The accuracy of the 1997 World Health Organization (WHO) dengue case definition has been debated for a decade, because the definition was very stringent, for instance, several researchers showed that apparently severe cases were misclassified as not severe. Therefore the WHO issued revised guidelines in 2009. Here, we retrospectively compared the performance of the WHO case definition of 2009 with the WHO case definition of 1997 in a detailed documented pediatric cohort from Indonesia. Intensive treatment intervention was used as an indicator of severity...

Virological surveillance of dengue in saint martin and saint barthelemy, French west indies, using blood samples on filter paper.

The American Journal of Tropical Medicine and Hygiene — Sun, 01 Jan 2012 05:00:00 +0100

Authors: Matheus S, Chappert JL, Cassadou S, Berger F, Labeau B, Bremand L, Winicki A, Huc-Anais P, Quenel P, Dussart P Abstract Abstract. To strengthen active dengue surveillance in Saint Martin and Saint Barthélemy, two French Caribbean islands, we evaluated the epidemiological usefulness of collecting blood samples from NS1-positive dengue patients on filter paper to identify the dengue serotypes circulating in these regions during a 27-month period. This approach allowed dengue serotypes to be identified by reverse transcriptase-polymerase chain reaction in 90.1% of the total set of 666 samples analyzed and, in 95.5% of the samples collected during the acute phase of the disease. This prospective virological surveillance using blood samples absorbed onto filter paper, which we...

Hospital-based prevalence of malaria and dengue in febrile patients in bangladesh.

The American Journal of Tropical Medicine and Hygiene — Sun, 01 Jan 2012 05:00:00 +0100

Authors: Faruque LI, Zaman RU, Alamgir AS, Gurley ES, Haque R, Rahman M, Luby SP Abstract Abstract. We conducted a nationwide study at six tertiary hospitals from December 2008 through November 2009 to investigate etiologies of febrile illnesses in Bangladesh. Febrile patients meeting a clinical case definition were enrolled from inpatient and outpatient medicine and pediatric units. We assessed 720 febrile patients over 12 months; 69 (9.6%) were positive for IgM antibodies against dengue virus by enzyme-linked immunosorbent assay, and four malaria patients (0.56%) were confirmed with immuno-chromatography and microscopic slide tests. We identified dengue cases throughout the year from rural (49%) and urban areas (51%). We followed-up 55 accessible dengue-infected patients two mont...

Etiology of acute, non-malaria, febrile illnesses in jayapura, northeastern papua, indonesia.

The American Journal of Tropical Medicine and Hygiene — Sun, 01 Jan 2012 05:00:00 +0100

Authors: Punjabi NH, Taylor WR, Murphy GS, Purwaningsih S, Picarima H, Sisson J, Olson JG, Baso S, Wangsasaputra F, Lesmana M, Oyofo BA, Simanjuntak CH, Subekti D, Corwin AL, Richie TL Abstract Abstract. We conducted a prospective, inpatient fever study in malaria-endemic Papua, Indonesia to determine non-malaria fever etiologies. Investigations included malaria blood films, blood culture, paired serologic samples analysis for dengue, Japanese encephalitis, leptospirosis, scrub typhus, murine typhus, and spotted fever group rickettsia. During 1997-2000, 226 patients (127 males and 99 females) 1-80 years of age (median age = 25 years) were enrolled. Positive blood cultures (n = 34, 15%) were obtained for Salmonella Typhi (n = 13), Escherichia coli (n = 8), Streptococcus pneumoniae (...

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Characteristics and Spectrum of Disease Among Ill Returned Travelers from Pre- and Post-Earthquake Haiti: The GeoSentinel Experience.

The American Journal of Tropical Medicine and Hygiene — Sun, 01 Jan 2012 05:00:00 +0100

Authors: Esposito DH, Han PV, Kozarsky PE, Walker PF, Gkrania-Klotsas E, Barnett ED, Libman M, McCarthy AE, Field V, Connor BA, Schwartz E, Macdonald S, Sotir MJ, Abstract Abstract. To describe patient characteristics and disease spectrum among foreign visitors to Haiti before and after the 2010 earthquake, we used GeoSentinel Global Surveillance Network data and compared 1 year post-earthquake versus 3 years pre-earthquake. Post-earthquake travelers were younger, predominantly from the United States, more frequently international assistance workers, and more often medically counseled before their trip than pre-earthquake travelers. Work-related stress and upper respiratory tract infections were more frequent post-earthquake; acute diarrhea, dengue, and Plasmodium falciparum malar...

A Cluster of Dengue Cases in American Missionaries Returning from Haiti, 2010.

The American Journal of Tropical Medicine and Hygiene — Sun, 01 Jan 2012 05:00:00 +0100

This report confirms recent DENV transmission in Haiti. Travelers to DENV-endemic areas should receive dengue education during pre-travel health consultations, follow mosquito avoidance recommendations, and seek medical care for febrile illness during or after travel. PMID: 22232444 [PubMed - as supplied by publisher] (Source: The American Journal of Tropical Medicine and Hygiene)

Infectious Diseases Seen in a Primary Care Clinic in Leogane, Haiti.

The American Journal of Tropical Medicine and Hygiene — Sun, 01 Jan 2012 05:00:00 +0100

Authors: Neuberger A, Tenenboim S, Golos M, Pex R, Krakowsky Y, Urman M, Vernet S, Schwartz E Abstract Abstract. All diseases diagnosed in a primary healthcare clinic situated in Leogane, Haiti, were recorded prospectively during a 7-month period. Among the patients in this cohort, 2,821 of 6,631 (42.6%) presented with an infectious disease. The three most common syndromes among the patients presenting with infections were respiratory tract infections (33.5%), suspected sexually transmitted diseases-mostly among females with recurrent disease (18.1%)-and skin and soft tissue infections, including multiple cases of tinea capitis (12.8%). Of the 255 patients presenting with undifferentiated fever, 76 (29.8%) were diagnosed with falciparum malaria. Other vector-borne diseases included...

Coronary artery bypass grafting and dengue fever.

Annals of Cardiac Anaesthesia — Sun, 01 Jan 2012 05:00:00 +0100

Authors: Wiwanitkit V PMID: 22234028 [PubMed - in process] (Source: Annals of Cardiac Anaesthesia)

Dengue outbreak in key west, Florida, USA, 2009.

Emerging Infectious Diseases — Sun, 01 Jan 2012 05:00:00 +0100

Authors: Radke EG, Gregory CJ, Kintziger KW, Sauber-Schatz EK, Hunsperger EA, Gallagher GR, Barber JM, Biggerstaff BJ, Stanek DR, Tomashek KM, Blackmore CG Abstract After 3 dengue cases were acquired in Key West, Florida, we conducted a serosurvey to determine the scope of the outbreak. Thirteen residents showed recent infection (infection rate 5%; 90% CI 2%-8%), demonstrating the reemergence of dengue in Florida. Increased awareness of dengue among health care providers is needed. PMID: 22257471 [PubMed - in process] (Source: Emerging Infectious Diseases)

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Daily newspaper view of dengue Fever epidemic, athens, Greece, 1927-1931.

Emerging Infectious Diseases — Sun, 01 Jan 2012 05:00:00 +0100

Authors: Louis C Abstract During the late summers of 1927 and 1928, a biphasic dengue epidemic affected the Athens, Greece, metropolitan area; >90% of the population became sick, and >1,000 persons (1,553 in the entire country) died. This epidemic was the most recent and most serious dengue fever epidemic in Europe. Review of all articles published by one of the most influential Greek daily newspapers (I Kathimerini) during the epidemic and the years that followed it did not shed light on the controversy about whether the high number of deaths resulted from dengue hemorrhagic fever after sequential infections with dengue virus types 1 and 2 or to a particularly virulent type 1 virus. Nevertheless, study of the old reports is crucial considering the relatively recent introduct...

Severe Nonfebrile Dengue Infection in an Adolescent After Postoperative Kidney Transplantation: A Case Report

Transplantation Proceedings — Sun, 01 Jan 2012 05:00:00 +0100

Abstract: We herein have reported a case of severe nonfebrile dengue infection complicated with refractory pancytopenia and a large perinephric hematoma with shock in a 16-year-old adolescent during the early postoperative period after kidney transplantation. After the diagnosis of end-stage renal disease she underwent living-related kidney transplantation. Thirteen days after successful transplantation, she exhibited a notable amount of ascites, bilateral pleural effusions, thrombocytopenia, and increased hemoglobin without pre-existent fever. Further investigation revealed positive dengue nonstructural protein 1 antigen (dengue NS1 Ag) and dengue virus serotype 1 by a reverse transcriptase-polymerase chain reaction (RT-PCR) in the patient's serum. She exhibited hemophagocytic syndrome, ...

A New Intelligence-Based Approach for Computer-Aided Diagnosis of Dengue Fever

Information Technology in Biomedicine, IEEE Transactions on - new TOC — Sun, 01 Jan 2012 05:00:00 +0100

Identification of the influential clinical symptoms and laboratory features that help in the diagnosis of dengue fever (DF) in early phase of the illness would aid in designing effective public health management and virological surveillance strategies. Keeping this as our main objective, we develop in this paper a new computational intelligence-based methodology that predicts the diagnosis in real time, minimizing the number of false positives and false negatives. Our methodology consists of three major components: 1) a novel missing value imputation procedure that can be applied on any dataset consisting of categorical (nominal) and/or numeric (real or integer); 2) a wrapper-based feature selection method with genetic search for extracting a subset of most influential symptoms that can di...

Arf4 and Arf5 Play a Crucial Role in Dengue Virus Secretion [Cell Biology]

Journal of Biological Chemistry — Fri, 30 Dec 2011 05:00:00 +0100

In this study, we demonstrate a crucial role for class II Arf proteins (Arf4 and Arf5) in the dengue flavivirus life cycle. We show that simultaneous depletion of Arf4 and Arf5 blocks recombinant subviral particle secretion for all four dengue serotypes. Immunostaining analysis suggests that class II Arf proteins are required at an early pre-Golgi step for dengue virus secretion. Using a horseradish peroxidase protein fused to a signal peptide, we show that class II Arfs act specifically on dengue virus secretion without altering the secretion of proteins through the constitutive secretory pathway. Co-immunoprecipitation data demonstrate that the dengue prM glycoprotein interacts with class II Arf proteins but not through its C-terminal VXPX motif. Finally, experiments performed with repli...

Inhibition of Dengue virus and West Nile virus proteases by click chemistry-derived benz[d]isothiazol-3(2H)-one derivatives.

Bioorganic and Medicinal Chemistry — Fri, 30 Dec 2011 05:00:00 +0100

Authors: Tiew KC, Dou D, Teramoto T, Lai H, Alliston KR, Lushington GH, Padmanabhan R, Groutas WC Abstract Two click chemistry-derived focused libraries based on the benz[d]isothiazol-3(2H)-one scaffold were synthesized and screened against Dengue virus and West Nile virus NS2B-NS3 proteases. Several compounds (4l, 7j-n) displayed noteworthy inhibitory activity toward Dengue virus NS2B-NS3 protease in the absence and presence of added detergent. These compounds could potentially serve as a launching pad for a hit-to-lead optimization campaign. PMID: 22249124 [PubMed - as supplied by publisher] (Source: Bioorganic and Medicinal Chemistry)

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Antiviral activity of four types of bioflavonoid against dengue virus type-2

BioMed Central — Wed, 28 Dec 2011 05:00:00 +0100

Conclusion: Results from the study suggest that only quercetin demonstrated significant anti-DENV-2 inhibitory activities. Other bioflavonoids, including daidzein, naringin and hesperetin showed minimal to no significant inhibition of DENV-2 virus replication. These findings, together with those previously reported suggest that select group of bioflavonoids including quercetin and fisetin, exibited significant inhibitory activities against dengue virus. This group of flavonoids, flavonol, could be investigated further to discover the common mechanisms of inhibition of dengue virus replication. (Source: BioMed Central)

Dengue virus infection in renal allograft recipients: a case series during 2010 outbreak

Transplant Infectious Disease — Wed, 28 Dec 2011 05:00:00 +0100

AbstractDengue virus infection is an emerging global threat caused by Arbovirus, a virus from Flaviridiae family, which is transmitted by mosquitoes, Aedes aegypti and Aedes albopictus. Renal transplant recipients who live in the endemic zones of dengue infection or who travel to an endemic zone could be at risk of this infection. Despite multiple epidemics and a high case fatality rate in the Southeast Asian region, only a few cases of dengue infection in renal transplant recipients have been reported. Here, we report a case series of 8 dengue viral infection in renal transplant recipients. Of the 8 patients, 3 developed dengue hemorrhagic shock syndrome and died. (Source: Transplant Infectious Disease)

Stability, oviposition attraction, and larvicidal activity of binary toxin from Bacillus sphaericus expressed in Escherichia coli.

Applied Microbiology and Biotechnology — Wed, 28 Dec 2011 05:00:00 +0100

In this study, the binA and binB genes were cloned and the recombinant BinAB protein was expressed in three strains of Escherichia coli. These recombinant strains were used in a toxicity assay against Culex quinquefasciatus larvae. The highest expression level was achieved when both proteins were expressed in a single operon construct. The BinAB protein expressed in the E. coli Arctic strain showed higher larvicidal activity than either of the recombinant proteins from the E. coli Ril or pLysS strains. Furthermore, it had the highest oviposition attraction (49.1%, P < 0.05). These data suggest that biologically active recombinant BinA and BinB toxins might be useful in mosquito control programs, delivered by inactivated bacterial cells or in traps. PMID: 22202967 [PubMed - as su...

Splenic rupture in dengue hemorrhagic fever: report of a case and review.

Japanese Journal of Infectious Diseases — Sun, 25 Dec 2011 15:27:37 +0100

This report documents a case of splenic rupture in a patient with dengue hemorrhagic fever who developed hypovolemic shock and subsequently died. Although splenic rupture is a known complication of other acute infections, it is a rare complication of dengue; therefore, it may be misdiagnosed. In the case described here, the poor outcome mainly resulted from the sudden onset of complications; the patient died of splenic rupture less than 24 h after admission, and the cause of death was confirmed at necropsy. PMID: 21788711 [PubMed - indexed for MEDLINE] (Source: Japanese Journal of Infectious Diseases)

Nonstructural protein 1 antibody-based epitope-blocking enzyme-linked immunosorbent assay to differentiate Japanese encephalitis virus from dengue virus infections in humans.

Japanese Journal of Infectious Diseases — Sun, 25 Dec 2011 15:27:37 +0100

Authors: Konishi E, Konishi M Abstract Japanese encephalitis virus (JEV) and the four dengue viruses (DENV1-4) are co-distributed in Southeast and South Asia. Since JEV is antigenically cross-reactive with DENV1-4, the differentiation between these viruses using antibody assays may be difficult. Herein, we describe the development of an epitope-blocking enzyme-linked immunosorbent assay (ELISA) using a monoclonal antibody specific for the nonstructural protein 1 (NS1) of JEV (JEV-NS1) to differentiate antibodies against JEV from those against DENV1-4. Hyperimmune mouse sera against JEV-NS1 showed >60% inhibition, whereas those against NS1 of DENV1-4 showed <30% inhibition. The present assay could therefore detect antibodies specific for JEV. For testing of human sera, a tempo...

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Endothelial cell surface expression of protein disulfide isomerase activates β1 and β3 integrins and facilitates dengue virus infection

Journal of Cellular Biochemistry — Thu, 22 Dec 2011 05:00:00 +0100

AbstractInfection with dengue virus (DENV) causes diseases ranging from mild dengue fever to severe hemorrhage or shock syndrome. DENV infection of endothelial cells may cause cell apoptosis or vascular leakage and result in clinical illness of hemorrhage. However, the endothelial cell molecules involved in DENV infection and the mechanisms governing virus‐cell interactions are still uncertain. Since protein diisulfide isomerase (PDI) reducing function at the cell surface was shown to be required for entry of certain viruses and bacteria, we explored the role of PDI expressed on endothelial cell surface in DENV infection. Using siRNA to knock down PDI, DENV infection was reduced which could be reversed by treating cells with a reducing agent Tris(2‐carboxyethyl)phosphine hydrochloride ...

The importance of accurate diagnosis of dengue fever

Future Virology — Wed, 21 Dec 2011 13:56:34 +0100

Future Virology , January 2012, Vol. 7, No. 1, Pages 53-62. (Source: Future Virology)

Genetics and immunity interact in dengue disease severity

EurekAlert! - Infectious and Emerging Diseases — Wed, 21 Dec 2011 05:00:00 +0100

(Broad Institute of MIT and Harvard) Why one person and not another succumbs to dengue disease has been suspected, but not known. An international team has nailed down an important piece of the puzzle. Working with data from two long-term clinical studies of children in Nicaragua, they have captured the complex connection between a person's immune status and the viral genetics of dengue, both of which evolve over time. (Source: EurekAlert! - Infectious and Emerging Diseases)

Dengue virus infection induces upregulation of hn RNP-H and PDIA3 for its multiplication in the host cell.

Virus Research — Wed, 21 Dec 2011 05:00:00 +0100

This study provides evidence that heterogeneous nuclear ribonucleoprotein H (hnRNP-H) and protein disulfide isomerase A3 (PDIA3) helps in DENV multiplication by suppressing TNF-α production in human monocytic THP1 cells. Proteomic analysis of infected cells, identified upregulation of the host cell proteins PDIA3 and hnRNP-H in comparison to mock infected cells. The functional role of hnRNP-H and PDIA3 in DENV infection was identified by down regulating hnRNP-H and PDIA3 genes with their specific siRNA duplexes which lead to decreased intracellular viral load. It also resulted in increased TNF-α level which mediates antiviral effect. This is the first study, which reports the role of PDIA3 and hnRNP-H in TNF-α production in DENV infected cells. Collectively, these results suggest that i...

Costs of dengue prevention and incremental cost of dengue outbreak control in Guantanamo, CubaCoûts de la prévention de la dengue et coût différentiel du contrôle de l’épidémie de la dengue à Guantanamo, à CubaCostes de la prevención del dengue y coste incremental del control de un brote de dengue en Guantánamo, Cuba

Tropical Medicine and International Health — Tue, 20 Dec 2011 21:24:59 +0100

Conclusions Intensive efforts to keep A. aegypti infestation low entail important economic costs for society. When a dengue outbreak does occur eventually, costs increase sharply. In‐depth studies should assess which mix of activities and actors could maximize the effectiveness and cost‐effectiveness of routine Aedes control and dengue prevention.Objectif: Evaluer le coût économique du contrôle de routine de l’Aedes aegypti dans un environnement à risque sans endémicité pour la dengue et les coûts marginaux encourus lors d’une épidémie sporadique.Méthodes: L’étude a été menée en 2006 dans la ville de Guantanamo, à Cuba. Nous avons adopté une perspective sociétale pour calculer les coûts dans les mois sans transmission de la dengue (janvier à juillet) ...

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Normalizing for Individual Cell Population Context in the Analysis of high-content Cellular Screens

BMC Bioinformatics - Latest articles — Tue, 20 Dec 2011 05:00:00 +0100

Conclusions: Using a cell-based analysis and normalization for population context, we achieve improved sensitivity and specificity not only on a individual protein level, but especially also on a pathway level. This leads to the identification of new host dependency factors of the hepatitis C and dengue viruses and higher reproducibility of results. (Source: BMC Bioinformatics - Latest articles)

Genetic Susceptibility to Dengue [Global Health]

JAMA — Tue, 20 Dec 2011 05:00:00 +0100

(Source: JAMA)

Dengue Fever Cases Subside in Florida, But Threat Remains

MedicineNet Cancer General — Mon, 19 Dec 2011 07:00:00 +0100

Title: Dengue Fever Cases Subside in Florida, But Threat RemainsCategory: Health NewsCreated: 12/16/2011 2:06:00 PMLast Editorial Review: 12/19/2011 (Source: MedicineNet Cancer General)

Population structure of the dengue viruses, Aragua, Venezuela, 2006-2007. Insights into dengue evolution under hyperendemic transmission

Journal of Dentistry — Sat, 17 Dec 2011 23:16:10 +0100

Publication year: 2011Source: Infection, Genetics and Evolution, Available online 17 December 2011Rosmari Rodriguez-Roche, Elci Villegas, Shelley Cook, Pauline AW Poh Kim, Yoandri Hinojosa, ...During the past three decades there has been a notable increase in dengue disease severity in Venezuela. Nevertheless, the population structure of the viruses being transmitted in this country is not well understood. Here, we present a molecular epidemiological study on dengue viruses (DENV) circulating in Aragua State, Venezuela during 2006-2007. Twenty-one DENV full-length genomes representing all of the 4 serotypes were amplified and sequenced directly from the serum samples. Notably, only DENV-2 was associated with severe disease. Phylogenetic trees constructed using Bayesian methods indicat...

Dengue Fever Cases Subside in Florida, But Threat Remains

The Doctors Lounge - Dermatology — Fri, 16 Dec 2011 18:00:00 +0100

Report finds no outbreak in Key West this year, but many residents may still be infected (Source: The Doctors Lounge - Dermatology)

Genetic and phenotypic characterization of sylvatic dengue virus type 4 strains.

Virology — Fri, 16 Dec 2011 05:00:00 +0100

This study investigated the genetic and phenotypic changes associated with emergence of human DENV-4 from its sylvatic ancestors. Analysis of complete genomes of 3 sylvatic and 4 human strains revealed high conservation of both the 5'- and 3'-untranslated regions but considerable divergence within the open reading frame. Additionally, the two ecotypes did not differ significantly in replication dynamics in cultured human liver (Huh-7), monkey kidney (Vero) or mosquito (C6/36) cells, although significant inter-strain variation within ecotypes was detected. These findings are in partial agreement with previous studies of DENV-2, where human strains produced a larger number of progeny than sylvatic strains in human liver cells but not in monkey or mosquito cells. PMID: 22178263 [PubMed - ...

Development of Dengue type-2 virus replicons expressing GFP reporter gene in study of viral RNA replication.

Virus Research — Fri, 16 Dec 2011 05:00:00 +0100

This study aimed to develop dengue virus (DENV) replicons expressing GFP reporter that would provide a fast in vitro system to analyze functional roles of specific DENV sequences in viral replication. Two classes of recombinant replicon constructs were generated; one was a RNA-launched replicon with a GFP gene directly inserted into a full-length DENV genome (FL-DENV/GFP), and the other consisted of 4 types of DNA-launched DENV subgenomic replicons with GFP replacement at various structural genes (Δ-DENV/GFP). The FL-DENV/GFP resulted in GFP expression in transfected cells with no viable DENV being recovered from the transfection. The Δ-DENV/GFP constructs with partial structural gene deletion (ΔC-, ΔCprM/M-, ΔprM/M-, or ΔE-) expressed bright and long lasting GFP. The GFP expression ...

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Dengue Virus Infection in AfricaDengue Virus Infection in Africa

Medscape Today Headlines — Thu, 15 Dec 2011 04:00:00 +0100

Surveillance is needed in Africa to determine the epidemiology and public health role of dengue. Emerging Infectious Diseases (Source: Medscape Today Headlines)

How The Body Fights Dengue Fever - New Discovery

Health News from Medical News Today — Wed, 14 Dec 2011 08:00:00 +0100

Worldwide, dengue fever strikes roughly 50 million people every year and takes the lives of thousands, but specific therapies or a vaccine for this mosquito-borne illness remain unavailable. A report in the online journal mBio® describes a new discovery about how the body fights the dengue virus, a finding that could explain differences in the ability to fight off the virus and help in developing a drug to boost this response. Dengue is relatively unknown here in the U.S... (Source: Health News from Medical News Today)

The entomopathogenic fungus Beauveria bassiana activate toll and JAK-STAT pathway-controlled effector genes and anti-dengue activity in Aedes aegypti.

Insect Biochemistry and Molecular Biology — Tue, 13 Dec 2011 05:00:00 +0100

Authors: Dong Y, Morton JC, Ramirez JL, Souza-Neto JA, Dimopoulos G Abstract Here we investigated the effect of Beauveria bassiana infection on the survival of Aedesaegypti mosquitoes and the modulation of their susceptibility to dengue virus infection. Application of B. bassiana caused a reduction in the life span of A. aegypti and hindered dengue virus replication in the mosquito midgut. Fungus infection induced the expression a variety anti-microbial and dengue virus restriction factor genes. Transient reverse genetic analyses showed that the JAK-STAT pathway is implicated anti-fungal defense of Aedes mosquitoes. Our data suggest that this B. bassiana-mediated anti-dengue activity is likely to be at least partly indirectly mediated through the activation of the mosquito's ant...

Use of parallel validation high-throughput screens to reduce false positives and identify novel dengue NS2B-NS3 protease inhibitors.

Antiviral Research — Tue, 13 Dec 2011 05:00:00 +0100

In this study, proof-of-concept high-throughput screenings (HTSs) were performed to unambiguously identify dengue 2 virus (DEN2V) NS2B-NS3pro inhibitors from a library of 2000 compounds. Validation screens were performed in parallel to concurrently eliminate insoluble, auto-fluorescing, and/or nonspecific inhibitors. Kinetic analyses of the hits revealed that parallel substrate fluorophore (AMC) interference controls and trypsin inhibition controls were able to reduce false positive rates due to solubility and fluorophore interference while the trypsin inhibition control additionally eliminated non-specific inhibitors. We identified five DEN2V NS2B-NS3pro inhibitors that also inhibited the related West Nile virus (WNV) protease (NS2B-NS3pro), but did not inhibit the trypsin protease. Bioch...

New Discovery on How the Body Fights Dengue Fever

American Society for Microbiology — Mon, 12 Dec 2011 20:49:00 +0100

WASHINGTON, DC -- December 12, 2012 -- Worldwide, dengue fever strikes roughly 50 million people every year and takes the lives of thousands, but specific therapies or a vaccine for this mosquito-borne illness remain unavailable. A report coming out in the online journal mBio® on December 13 describes a new discovery about how the body fights the dengue virus, a finding that could explain differences in the ability to fight off the virus and help in developing a drug to boost this response. Read more... (Source: American Society for Microbiology)

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New discovery on how the body fights dengue fever

EurekAlert! - Infectious and Emerging Diseases — Mon, 12 Dec 2011 05:00:00 +0100

(American Society for Microbiology) A report coming out in the online journal mBio on Dec. 13 describes a new discovery about how the body fights the dengue virus, a finding that could explain differences in the ability to fight off the virus and help in developing a drug to boost this response. (Source: EurekAlert! - Infectious and Emerging Diseases)

Comparison of wing geometry data and genetic data for assessing the population structure ofAedes aegypti

Journal of Dentistry — Sat, 10 Dec 2011 00:32:51 +0100

Publication year: 2011Source: Infection, Genetics and Evolution, Available online 8 December 2011Paloma Oliveira Vidal, Lincoln SuesdekAedes aegyptiis the most important vector of dengue viruses in tropical and subtropical regions. Because vaccines are still under development, dengue prevention depends primarily on vector control. Population genetics is a common approach in research involvingAe. aegypti. In the context of medical entomology, wing morphometric analysis has been proposed as a strong and low-cost complementary tool for investigating population structure. Therefore, we comparatively evaluated the genetic and phenotypic variability of population samples ofAe. aegyptifrom four sampling sites in the metropolitan area of São Paulo city, Brazil. The distances between the sites r...

Characterization of Bacillus thuringiensis isolates with potential for control of Aedes aegypti (Linnaeus, 1762) (Diptera: Culicidae).

Acta Tropica — Fri, 09 Dec 2011 05:00:00 +0100

Authors: Santos FP, Lopes J, Vilas-Bôas GT, Zequi JA Abstract Aedes aegypti (Linnaeus) is the vector of dengue virus in Brazil. Bioinsecticides based on Bacillus thuringiensis have shown satisfactory results in the control of Diptera, due to the production of proteins called Cry and Cyt. The aim of the present study was to select B. thuringiensis isolates carrying the cry and cyt genes, which are efficient in the control of Ae. aegypti. A collection of 27 isolates of B. thuringiensis, derived from various regions in Brazil, was evaluated using selective bioassays against A. aegypti larvae. Of the 27 isolates, five showed 100% larval mortality at a concentration of 0.05ppm and the toxicity of these isolates in quantitative bioassays did not differ significantly at temperatures of 1...

Antiviral activities of extracts and phenolic components of two Spondias species against dengue virus

Journal of Venomous Animals and Toxins including Tropical Diseases — Thu, 08 Dec 2011 22:39:20 +0100

In recent years, the search for natural plant products to fight viral diseases has been increasing. In this work, two Spondias species, namely S. mombin and S. tuberosa, found in Ceará state (Brazil), and their main phenolic components were evaluated against dengue virus. In vitro antiviral tests were performed against type-2 dengue virus by the MTT method and standard cytopathic effect reduction assay in C6/36 cells. Cytotoxicity was also evaluated by MTT. The presence of phenolic compounds quercetin, rutin, and ellagic acid in plant extracts was characterized by HPLC analysis. Both Spondias species extracts and components were nontoxic to the cells whereas rutin and quercetin displayed relevant antiviral activity with IC50 of 362.68 µg/mL and 500 µg/mL, respectively. (Source: Journal ...

Comparison of wing geometry data and genetic data for assessing the population structure of Aedes aegypti.

Infection, Genetics and Evolution — Thu, 08 Dec 2011 05:00:00 +0100

Authors: Vidal PO, Suesdek L Abstract Aedes aegypti is the most important vector of dengue viruses in tropical and subtropical regions. Because vaccines are still under development, dengue prevention depends primarily on vector control. Population genetics is a common approach in research involving Ae. aegypti. In the context of medical entomology, wing morphometric analysis has been proposed as a strong and low-cost complementary tool for investigating population structure. Therefore, we comparatively evaluated the genetic and phenotypic variability of population samples of Ae. aegypti from four sampling sites in the metropolitan area of São Paulo city, Brazil. The distances between the sites ranged from 7.1 to 50km. This area, where knowledge on the population genetics of this m...

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Dengue in the Middle East: a neglected, emerging disease of importance

Transactions of the Royal Society of Tropical Medicine and Hygiene — Mon, 05 Dec 2011 22:39:32 +0100

Abstract: Dengue transmission has increased worldwide, particularly in Asia and Latin America since the 1970s, but limited information on the disease is available from the Middle East. Saudi Arabia and Yemen have reported a few epidemics of dengue. Three of the four dengue virus serotypes (DENV-1–3) have been reported in the region. Climate conditions in the Middle East are not favourable for the disease vector, but all other risk factors for dengue are potentially increasing. The existence of a large immigrant work force from dengue-endemic countries, increased travel from and to dengue-endemic countries and increased urbanization are expected to increase the likelihood of the emergence of dengue in the Middle East. (Source: Transactions of the Royal Society of Tropical Medicine and Hyg...

Internally Controlled, Generic Real-Time PCR for Quantification and Multiplex Real-Time PCR with Serotype-Specific Probes for Serotyping of Dengue Virus Infections

Journal of Biophysics — Mon, 05 Dec 2011 14:36:58 +0100

Dengue has become a global public health problem and a sensitive diagnostic test for early phase detection can be life saving. An internally controlled, generic real-time PCR was developed and validated by testing serial dilutions of a DENV positive control RNA in the presence of a fixed amount of IC with results showing a good linearity (R2=0.9967) and a LOD of at least 1.95×104 copies/mL. Application of the generic PCR on 136 patient samples revealed a sensitivity of 95.8% and specificity of 100%. A newly developed multiplex real-time PCR with serotype-specific probes allowed the serotyping of DENV for 80 out of 92 (87%) generic real-time PCR positive patients. Combined these real-time PCRs offer a convenient diagnostic tool for the sensitive and specific quanti...

CD16+ natural killer cells play a limited role against primary dengue virus infection in tamarins

Archives of Virology — Fri, 02 Dec 2011 17:30:16 +0100

Abstract CD16 is a major molecule expressed on NK cells. To directly assess the role of natural killer (NK) cells in dengue virus (DENV) infection in vivo, CD16 antibody-treated tamarins were inoculated with a DENV-2 strain. This resulted in the transient depletion of CD16+ NK cells, whereas no significant effects on the overall levels or kinetics of plasma viral loads and antiviral antibodies were observed in the treated monkeys when compared to control monkeys. It remains elusive whether the CD16− NK subpopulation could play an important role in the control of primary DENV infection. Content Type Journal ArticleCategory Brief ReportPages 1-6DOI 10.1007/s00705-011-1178-6Authors Tomoyuki Yoshida, Tsukuba Primate Research Center, National Institute of Biomedical Innova...

Structural insights into the neutralization mechanism of a higher primate antibody against dengue virus

The EMBO Journal AOP — Fri, 02 Dec 2011 05:00:00 +0100

Authors: Joseph JB Cockburn, M Erika Navarro Sanchez, Ana P Goncalvez, Elena Zaitseva, Enrico A Stura, Carlos M Kikuti, Stéphane Duquerroy, Philippe Dussart, Leonid V Chernomordik, Ching-Juh Lai & Felix A Rey (Source: The EMBO Journal AOP)

A Review of Zoonotic Disease Surveillance Supported by the Armed Forces Health Surveillance Center

Zoonoses and Public Health — Thu, 01 Dec 2011 05:00:00 +0100

SummaryThe Armed Forces Health Surveillance Center (AFHSC), Division of Global Emerging Infections Surveillance and Response System conducts disease surveillance through a global network of US Department of Defense research laboratories and partnerships with foreign ministries of agriculture, health and livestock development in over 90 countries worldwide. In 2010, AFHSC supported zoonosis survey efforts were organized into four main categories: (i) development of field assays for animal disease surveillance during deployments and in resource limited environments, (ii) determining zoonotic disease prevalence in high‐contact species which may serve as important reservoirs of diseases and sources of transmission, (iii) surveillance in high‐risk human populations which are more likely to ...

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Spatial Stability of Adult Aedes aegypti Populations.

The American Journal of Tropical Medicine and Hygiene — Thu, 01 Dec 2011 05:00:00 +0100

This study explored if the number of female adults of Ae. aegypti in BG-Sentinel traps was clustered and if their spatial distribution changed in time in two neighborhoods in San Juan, Puerto Rico. Traps were uniformly distributed across each neighborhood (130 m from each other), and samples were taken every 3 weeks. Global and local spatial autocorrelations were explored. Spatial stability existed if the rank order of trap captures was kept in time. There was lack of global autocorrelation in both neighborhoods, precluding their stratification for control purposes. Hot and cold spots were identified, revealing the highly focal nature of Ae. aegypti. There was significant spatial stability throughout the study in both locations. The consistency in trap productivity in time could be used to...

Dengue maculopathy in a traveler.

The American Journal of Tropical Medicine and Hygiene — Thu, 01 Dec 2011 05:00:00 +0100

Authors: Ujiie M, Moi ML, Takeda N PMID: 22144427 [PubMed - in process] (Source: The American Journal of Tropical Medicine and Hygiene)

Seroprevalence of alkhurma and other hemorrhagic Fever viruses, saudi arabia.

Emerging Infectious Diseases — Thu, 01 Dec 2011 05:00:00 +0100

Authors: Memish ZA, Albarrak A, Almazroa MA, Al-Omar I, Alhakeem R, Assiri A, Fagbo S, Macneil A, Rollin PE, Abdullah N, Stephens G Abstract A 2009 deployment of military units from several Saudi Arabian provinces to Jazan Province, Saudi Arabia, enabled us to evaluate exposure to Alkhurma, Crimean-Congo, dengue, and Rift Valley hemorrhagic fever viruses. Seroprevalence to all viruses was low; however, Alkhurma virus seroprevalence was higher (1.3%) and less geographically restricted than previously thought. PMID: 22172587 [PubMed - in process] (Source: Emerging Infectious Diseases)

Guillain-Barré syndrome and dengue.

Revista do Instituto de Medicina Tropical de Sao Paulo — Thu, 01 Dec 2011 05:00:00 +0100

Authors: Wiwanitkit V PMID: 22183462 [PubMed - in process] (Source: Revista do Instituto de Medicina Tropical de Sao Paulo)

Co-infection of Dengue virus by serotypes 3 and 4 in patients from Amazonas, Brazil.

Revista do Instituto de Medicina Tropical de Sao Paulo — Thu, 01 Dec 2011 05:00:00 +0100

We report here four cases of DENV-3/DENV-4 co-infection detected by serological and molecular tests among 674 patients with acute undifferentiated fever from the tropical medicine reference center of Manaus City, Brazil, between 2005 and 2010. Analysis of the sequences obtained indicated the presence of genotype 3 and 1 for DENV-3 and DENV-4 respectively. PMID: 22183455 [PubMed - in process] (Source: Revista do Instituto de Medicina Tropical de Sao Paulo)

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Evaluation of dengue NS1 antigen detection for diagnosis in public health laboratories, São Paulo State, 2009.

Revista do Instituto de Medicina Tropical de Sao Paulo — Thu, 01 Dec 2011 05:00:00 +0100

Authors: Bisordi I, Rocco IM, Suzuki A, Katz G, Silveira VR, Maeda AY, Souza RP, Bassi MG, Del Tedesco EF, Freitas E, Bessa TÁ, Abstract The present work evaluated the diagnostic accuracy of detection of Dengue NS1 antigen employing two NS1 assays, an immunochromatographic assay and ELISA, in the diagnostic routine of Public Health laboratories. The results obtained with NS1 assay were compared with virus isolation and, in a subpopulation of cases, they were compared with the IgM-ELISA results obtained with convalescent samples. A total of 2,321 sera samples were analyzed by one of two NS1 techniques from March to October 2009. The samples were divided into five groups: groups I, II and III included samples tested by NS1 and virus isolation, and groups IV and V included patients ...

[Death from dengue fever as a sentinel event for evaluation of quality of healthcare: a case study in two municipalities in Northeast Brazil, 2008].

Cadernos de Saude Publica — Thu, 01 Dec 2011 05:00:00 +0100

Authors: Figueiró AC, Hartz ZM, Brito CA, Samico I, Siqueira Filha NT, Cazarin G, Braga C, Cesse EÂ Abstract Despite the existing resources for adequate dengue patient care in the Brazilian healthcare system, the case-fatality rate for the disease is still high in the country. In order to identify factors associated with dengue-related death, this study evaluated quality of care according to the degree of implementation of specific measures, the technical and scientific quality of care, and access to health services in two municipalities (counties) in Northeast Brazil. An evaluative study of the implementation analysis type was performed, with death from dengue as the sentinel event for quality of care. To assess the degree of implementation and quality of care, the study scored ...

Dengue vaccines: closer but not there yet.

Memorias do Instituto Oswaldo Cruz — Thu, 01 Dec 2011 05:00:00 +0100

Authors: Galler R, Bonaldo MC, Alves AM PMID: 22241108 [PubMed - in process] (Source: Memorias do Instituto Oswaldo Cruz)

When Less is More: Can We Abandon Prophylactic Platelet Transfusion in Dengue Fever?

Annals of the Academy of Medicine, Singapore — Thu, 01 Dec 2011 05:00:00 +0100

Authors: Kurukularatne C, Dimatatac F, Teo DL, Lye DC, Leo YS Abstract Dengue fever (DF) has several hematological manifestations including thrombocytopenia and increased bleeding risk. Prophylactic platelet transfusion-in the absence of major bleeding-is utilized in DF with thrombocytopenia with the intention of preventing hemorrhagic complications. However, prophylactic platelet transfusion in DF is neither standardized nor supported by clinical evidence. We conclude that risks, costs and poor resource utilization associated with prophylactic platelet transfusion in DF far outweigh any potential hematological benefit, and as such, should not constitute routine clinical practice. PMID: 22294065 [PubMed - in process] (Source: Annals of the Academy of Medicine, Singapore)

Dengue Knowledge, Attitudes, and Practices among Primary Care Physicians in Singapore.

Annals of the Academy of Medicine, Singapore — Thu, 01 Dec 2011 05:00:00 +0100

Conclusions: While no major gaps in knowledge about dengue were identified in PCPs in Singapore, there were significant variations in clinical practice by physician age group and practice setting. The results of this survey provide a useful opportunity to identify strengths and areas in need of improved awareness in primary care management of dengue. PMID: 22294064 [PubMed - in process] (Source: Annals of the Academy of Medicine, Singapore)

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Subcutaneous Infection with Non-mouse Adapted Dengue Virus D2Y98P Strain Induces Systemic Vascular Leakage in AG129 Mice.

Annals of the Academy of Medicine, Singapore — Thu, 01 Dec 2011 05:00:00 +0100

Conclusion: We believe that this novel mouse model of DEN-associated vascular leakage will contribute to a better understanding of DEN pathogenesis and represents a relevant platform for testing novel therapeutic treatments and interventions. PMID: 22294063 [PubMed - in process] (Source: Annals of the Academy of Medicine, Singapore)

Dengue Research in Singapore Marking the Inaugural ASEAN Dengue Day.

Annals of the Academy of Medicine, Singapore — Thu, 01 Dec 2011 05:00:00 +0100

Authors: Leo YS, Ng LC, Cutter J PMID: 22294062 [PubMed - in process] (Source: Annals of the Academy of Medicine, Singapore)

Immunological consequences of arthropod vector‐derived salivary factors

European Journal of Immunology — Wed, 30 Nov 2011 23:53:35 +0100

AbstractDiseases, such as malaria, dengue, leishmaniasis and tick‐borne encephalitis, affect a substantial percentage of the world's population and continue to result in significant morbidity and mortality. One common aspect of these diseases is that the pathogens that cause them are transmitted by the bite of an infected arthropod (e.g. mosquito, sand fly, tick). The pathogens are delivered into the skin of the mammalian host along with arthropod saliva, which contains a wide variety of bioactive molecules. These saliva components are capable of altering hemostasis and immune responses and may contribute to the ability of the pathogen to establish an infection. The biological and immunological events that occur during pathogen transmission are poorly understood but may hold the key to n...

Increase of Plasminogen Activator Inhibitor-1 and Decrease of Transforming Growth Factor-B1 in Children with Dengue Haemorrhagic Fever in Indonesia

Journal of Tropical Pediatrics — Wed, 30 Nov 2011 05:00:00 +0100

In conclusion, elevated PAI-1 concentrations in DHF were associated with platelet counts and plasma leakage. (Source: Journal of Tropical Pediatrics)

Risk Factors of Dengue Shock Syndrome in Children

Journal of Tropical Pediatrics — Wed, 30 Nov 2011 05:00:00 +0100

This retrospective hospital-based study was conducted to evaluate the various risk factors associated with dengue shock syndrome (DSS) in patients (≤18 years of age) of dengue hemorrhagic fever (DHF). Medical records of these 483 patients with DHF (IgM serology positive) were analyzed with reference to shock for various clinical and biochemical parameters. Of the 483 children, 405 were categorized in DHF group (grade I, 282 children; grade II, 123 children) and 78 in DSS group (grade III, 59 children; grade IV, 19 children). Using univariate and multivariate logistic regression and p-value of <0.05 as significant, the presence of spontaneous bleeding, hepatomegaly, signs of capillary leakage like ascitis and pleural effusion, leucopenia <4000 mm3 and age >5 years were found out...

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Composition of the sequence downstream of the dengue virus 5' cyclization sequence (dCS) affects viral RNA replication.

Virology — Wed, 30 Nov 2011 05:00:00 +0100

Authors: Friebe P, Peña J, Pohl MO, Harris E Abstract RNA replication of dengue virus (DENV) requires an RNA-RNA mediated circularization of the viral genome, which includes at least three sets of complementary RNA sequences on both ends of the genome. The 5' and the 3' untranslated regions form several additional RNA elements that are involved in regulation of translation and required for RNA replication. Communication between the genomic termini results in a structural reorganization of the RNA elements, forming a functional RNA panhandle structure. Here we report that the sequence composition downstream of the 5' CS element in the capsid gene, designated as downstream CS (dCS) sequence - but not the capsid protein - also influences the ability of the viral genome to circularize...

Dengue Control Works Better With Local Help

Health News from Medical News Today — Tue, 29 Nov 2011 08:00:00 +0100

There is no vaccine against dengue, an emerging tropical disease regularly also hitting tourists, so the only way of controlling it is by suppressing the mosquitoes transmitting the disease. Easier said than done, and cooperation of the local communities is an important factor in the success of a campaign. So observed scientists from the Antwerp Institute of Tropical Medicine (ITG). For her work in dengue control on two continents ITG-researcher Veerle Vanlerberghe obtained a PhD at the ITG and Ghent University... (Source: Health News from Medical News Today)

Wegener’s granulomatosis with dengue fever: an unusual association

APLAR Journal of Rheumatology — Tue, 29 Nov 2011 05:00:00 +0100

(Source: APLAR Journal of Rheumatology)

U18666A, an intra-cellular cholesterol transport inhibitor, inhibits dengue virus entry and replication.

Antiviral Research — Tue, 29 Nov 2011 05:00:00 +0100

Authors: Poh MK, Shui G, Xie X, Shi PY, Wenk MR, Gu F Abstract The level of cholesterol in host cells has been shown to affect viral infection. However, it is still not understood why this level of regulation is important for successful infection. We have shown in this study that dengue virus infection was affected when the cholesterol intake in infected cells was disrupted using a cholesterol transport inhibitor, U18666A. The antiviral effect was found to result from two events: retarded viral trafficking in the cholesterol-loaded late endosomes/lysosomes and suppressed de novo sterol biosynthesis in treated infected cells. We also observed an additive antiviral effect of U18666A with C75, a fatty acid synthase inhibitor, suggesting dengue virus relies on both the host cholesterol...

Arylcyanoacrylamides as inhibitors of the Dengue and West Nile virus proteases.

Bioorganic and Medicinal Chemistry — Tue, 29 Nov 2011 03:54:21 +0100

Authors: Nitsche C, Steuer C, Klein CD Abstract The 3-aryl-2-cyanoacrylamide scaffold was designed as core pharmacophore for inhibitors of the Dengue and West Nile virus serine proteases (NS2B-NS3). A total of 86 analogs was prepared to study the structure-activity relationships in detail. Thereby, it turned out that the electron density of the aryl moiety and the central double bond have a crucial influence on the activity of the compounds, whereas the influence of substituents of the amide residue is less relevant. The para-hydroxy substituted analog was found to be the most potent inhibitor in this series with a K(i)-value of 35.7μM at the Dengue and 44.6μM at the West Nile virus protease. The aprotinin competition assay demonstrates a direct interaction of the inhibitor molec...

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Dengue hemorrhagic fever-associated immunomediators induced via maturation of dengue virus nonstructural 4B protein in monocytes modulate endothelial cell adhesion molecules and human microvascular endothelial cells permeability.

Virology — Mon, 28 Nov 2011 05:00:00 +0100

In this report using primary human microvascular endothelial cells (HMVEC) transwell permeability model and HMVEC monolayer, we demonstrate that the immunomediators secreted in the supernatants of DENV-infected monocytes increase HMVEC permeability and expression of ICAM-1, VCAM-1 and E-selectin. Moreover, maturation of NS4B via cleavage of 2KNS4B is sufficient to induce immunomediators that cause HMVEC phenotypic changes, which appear to be synergistically induced by TNFα and IL-8. These data suggest that therapies targeting the maturation steps of NS4B, particularly 2KNS4B processing, may reduce overall DHF-associated immunomediator levels, thereby reducing DHF-associated morbidity and mortality. Alternatively, TNFα inhibitors may be a valid intervention strategy during the later stage...

Association of platelet count and serological markers of dengue infection- importance of NS1 antigen

Indian Journal of Medical Microbiology — Thu, 24 Nov 2011 05:00:00 +0100

Conclusions: Inclusion of NS1 in the diagnosis of dengue increases the detection rate significantly. In cases of fever, thrombocytopenia is more consistently found in dengue positive rather than dengue negative subjects. It correlates well when NS1 and IgM are detected simultaneously. (Source: Indian Journal of Medical Microbiology)

Comparison of Plaque- and Enzyme-linked Immunospot-based Assays to Measure the Neutralizing Activities of Monoclonal Antibodies Specific to Domain III of Dengue Virus Envelope Protein.

Clinical and Vaccine Immunology — Wed, 23 Nov 2011 05:00:00 +0100

Authors: Liu L, Wen K, Li J, Hu D, Huang Y, Qiu L, Cai J, Che X Abstract The plaque reduction neutralization test (PRNT) is used widely to measure the neutralization activity of anti-dengue virus (DENV) antibodies, but it is time-consuming, labor-intensive and has low sample throughput. For fast and convenient measurement of neutralizing antibodies, especially in evaluating the efficiency of the DENV vaccines on a large scale, a new method is needed to replace PRNT. In recent decades, several microneutralization assays have been developed to overcome the limitations of PRNT. In the present study, we evaluated one of these, enzyme-linked immunospot microneutralization test (ELISPOT-MNT), in comparison with PRNT. ELISPOT-MNT is performed in 96-well format, the plaques are developed a...

Primary and probable secondary dengue virus (DV) infection rates in relation to age among DV IgM-positive patients residing on the United States mainland versus Caribbean islands.

Clinical and Vaccine Immunology — Wed, 23 Nov 2011 05:00:00 +0100

Authors: Prince HE, Yeh C, Lapé-Nixon M Abstract Dengue virus (DV) primary infection and probable secondary infection rates in relation to patient age (years) were determined for DV IgM+ US mainland residents (presumed travelers to endemic areas) and Caribbean Island residents (endemic area) by evaluating IgG status and IgG avidity. Regardless of place of residence, most patients ≤20 exhibited primary infection and most patients >60 exhibited probable secondary infection. Among patients 21-60, the primary infection rate was markedly higher in US residents. PMID: 22116685 [PubMed - as supplied by publisher] (Source: Clinical and Vaccine Immunology)

Clinical characteristics and outcomes of patients with acute lung injury and ARDS

Journal of Postgraduate Medicine — Tue, 22 Nov 2011 05:00:00 +0100

Conclusion : Malaria, leptospirosis, and undiagnosed fever were the main etiologies followed by pneumonia, urinary tract infections, and pancreatitis. Both the PaO 2 /FiO 2 ratio and lung injury score (LIS) at the time of admission were significant predictors of the outcome and of necessity of mechanical ventilation. PaO 2 /FiO 2 was a better predictor of duration of stay at the intensive care unit than the LIS. Sepsis, acidosis, hypotension, and multiorgan failure were individual predictors of mortality in patients with ALI/ARDS while age, sex, anemia, thrombocytopenia, renal failure, hepatic failure, and X-ray picture were not predictors of the outcome. (Source: Journal of Postgraduate Medicine)

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Neuralgic amyotrophy associated with dengue fever: Case series of three patients

Journal of Postgraduate Medicine — Tue, 22 Nov 2011 05:00:00 +0100

R Verma, P Sharma, N Khurana, LN SharmaJournal of Postgraduate Medicine 2011 57(4):329-331Dengue is an acute mosquito borne viral infection caused by one of the four distinct serotype of dengue viruses (type 1-4), belonging to flavivirus family. Dengue fever, an arboviral infection is known to cause various neurological complications. Commonly reported neurological manifestations associated with dengue infection are encephalopathy, myelopathy, stroke, Guillain-Barre syndrome and hypokalemic paralysis. Brachial amyotrophy associated with dengue infection were not described previously. Here, we describe three patients presenting with brachial neuritis associated with dengue infection. Dengue infection should be considered in the etiological list of brachial neuritis in dengue endemic areas, ...

Climate Change May Make Insect-Born Diseases Harder to Control

Scientific American - Official RSS Feed — Mon, 21 Nov 2011 21:50:00 +0100

Climate change can influence how infectious diseases affect the world, particularly illnesses spread by vectors like mosquitoes. Now scientists have developed some understanding about how rainfall and temperature can influence malaria, dengue and West Nile virus infections as well as ways to combat them. [More] (Source: Scientific American - Official RSS Feed)

Climate Change May Make Insect-Borne Diseases Harder to Control

Scientific American - Official RSS Feed — Mon, 21 Nov 2011 21:50:00 +0100

Molecular detection and characterization of West Nile virus associated with multifocal retinitis in patients from southern India

International Journal of Infectious Diseases — Fri, 18 Nov 2011 05:00:00 +0100

Conclusions: The association of West Nile virus with ocular infection in South India during an epidemic of mysterious fever in the first half of 2010 was clearly established through molecular approaches employing envelope gene-specific real-time RT-PCR and RT-LAMP assays followed by nucleotide sequencing. (Source: International Journal of Infectious Diseases)

Q&A: Cuba Advancing Towards a Dengue Vaccine

IPS Inter Press Service - Health — Thu, 17 Nov 2011 15:13:34 +0100

"We don't like to talk about our specific goals," says Cuban virologist María Guadalupe Guzmán, as a subtle way to avoid going into too much detail about the research she is heading up to develop a dengue vaccine. (Source: IPS Inter Press Service - Health)

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Seroprevalence of dengue infection: a cross-sectional survey in mainland Tanzania and on Pemba Island, Zanzibar

International Journal of Infectious Diseases — Wed, 16 Nov 2011 05:00:00 +0100

Conclusion: These findings provide the first baseline data on dengue seroprevalence in the country. No recent dengue virus circulation in Tanzania and in the Zanzibar archipelago up until the early 1990s is reported. (Source: International Journal of Infectious Diseases)

DRACO drug effective against most viruses (Double-stranded RNA Activated Caspase Oligomerizer)

Clinical Cases and Images — Tue, 15 Nov 2011 13:41:00 +0100

"New drug could cure nearly any viral infection", proclaimed the media. The drug works by targeting a type of RNA (dsRNA) produced only in cells that have been infected by viruses. “In theory, it should work against all viruses."Currently there are relatively few antiviral therapeutics, and most which do exist are highly pathogen-specific.The MIT researchers developed a new broad-spectrum antiviral approach, called Double-stranded RNA (dsRNA) Activated Caspase Oligomerizer (DRACO).DRACO selectively induces apoptosis in cells containing viral dsRNA, rapidly killing infected cells without harming uninfected cells.The drugs were nontoxic to mammalian cells and effective against 15 different viruses, including dengue flavivirus, arenaviruses, bunyavirus, and H1N1 influenza.DRACOs have the po...

PD 404,182 is a virucidal small molecule that disrupts hepatitis C virus and human immunodeficiency virus.

Antimicrobial Agents and Chemotherapy — Mon, 14 Nov 2011 05:00:00 +0100

We describe a virucidal small molecule, PD 404,182, effective against hepatitis C virus (HCV) and human immunodeficiency virus (HIV). The median IC(50) values for the antiviral effect of PD 404,182 against HCV and HIV in cell culture are 11 μM and 1 μM, respectively. The antiviral activity of PD 404,182 is due to physical disruption of virions that is accompanied to varying degrees (depending on the virus and exposure temperature/time) by release of viral nucleic acids into the surrounding medium. PD 404,182 does not directly lyse liposomal membranes even after extended exposure and shows no attenuation in antiviral activity when pre-incubated with liposomes of various lipid compositions, suggesting that the compound inactivates viruses through interaction with a non-lipid structural com...

Filgrastim as a Rescue Therapy for Persistent Neutropenia in a Case of Dengue Hemorrhagic Fever with Acute Respiratory Distress Syndrome and Myocarditis

Advances in Pharmacological Sciences — Thu, 10 Nov 2011 08:04:48 +0100

We present a novel use of filgrastim as a rescue therapy in a patient with dengue hemorrhagic fever (DHF) with acute respiratory distress syndrome (ARDS), myocarditis, and febrile neutropenia and not responding to standard management. (Source: Advances in Pharmacological Sciences)

Enhancement of the detection limit for lateral flow immunoassays: Evaluation and comparison of bioconjugates.

Journal of Immunological Methods — Thu, 10 Nov 2011 05:00:00 +0100

Authors: Linares EM, Kubota LT, Michaelis J, Thalhammer S Abstract There is an increasing demand for convenient and accurate point-of-care tools that can detect and diagnose different stages of a disease in remote or impoverished settings. In recent years, lateral flow immunoassays (LFIA) have been indicated as a suitable medical diagnostic tool for these environments because they require little or no sample preparation, provide rapid and reliable results with no electronic components and thus can be manufactured at low costs and operated by unskilled personnel. However, even though they have been successfully applied to acute and chronic disease detection, LFIA based on gold nanoparticles, the standard marker, show serious limitations when high sensitivity is needed, such as early...

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Binding of Low Molecular Weight Inhibitors Promotes Large Conformational Changes in the Dengue Virus NS2B-NS3 Protease: Fold Analysis by Pseudocontact Shifts

Journal of the American Chemical Society — Wed, 09 Nov 2011 14:56:41 +0100

Journal of the American Chemical SocietyDOI: 10.1021/ja208435s (Source: Journal of the American Chemical Society)

Mosquitoes Engineered To Kill Their Own Kind

NPR Health and Science — Fri, 04 Nov 2011 17:00:00 +0100

Reporting in Nature Biotechnology, researchers write of genetically engineering mosquitoes to pass lethal genes to their offspring, in hopes of crashing populations of one dengue-transmitting species. Science writer Bijal Trivedi talks about recent tests of the bugs, and the concerns of critics.» E-Mail This » Add to Del.icio.us (Source: NPR Health and Science)

Epidemic: Control of dengue fever in Pakistan

Nature — Wed, 02 Nov 2011 04:00:00 +0100

Nature 479, 7371 (2011). doi:10.1038/479041d Author: Mohammad A. Rai Five years ago the Indian subcontinent experienced its first epidemic of dengue fever, with more than 5,000 people in India and more than 2,000 in Pakistan hospitalized (M. A.Rai and H.KhanJ. Clin. Virol.38, 269–270; doi:10.1016/j.jcv.2006.12.010 (Source: Nature)

Do viral infections mimic bacterial sepsis? The role of microvascular permeability: A review of mechanisms and methods.

Antiviral Research — Wed, 02 Nov 2011 04:00:00 +0100

Authors: Steinberg BE, Goldenberg NM, Lee WL Abstract A dysregulated immune response and functional immunosuppression have been considered the major mechanisms of the bacterial sepsis syndrome. More recently, the loss of endothelial barrier function and resultant microvascular leak have been found to be a key determinant of the pathogenesis of bacterial sepsis. Whether a similar paradigm applies to systemic viral syndromes is not known. Answering this question has far-reaching implications for the development of future anti-viral therapeutic strategies. In this review, we provide an overview of the structure and function of the endothelium and how its barrier integrity is compromised in bacterial sepsis. The various in vitro and in vivo methodologies available to investigate vascul...

Validation of probability equation and decision tree in predicting subsequent dengue hemorrhagic Fever in adult dengue inpatients in singapore.

The American Journal of Tropical Medicine and Hygiene — Tue, 01 Nov 2011 04:00:00 +0100

This study validated these in a predominantly dengue serotype 2 cohort in 2007. The 1,017 adult dengue patients admitted to Tan Tock Seng Hospital, Singapore had a median age of 35 years. Of 933 patients without DHF on admission, 131 progressed to DHF. The probability equation predicted DHF with a sensitivity (Sn) of 94%, specificity (Sp) 17%, positive predictive value (PPV) 16%, and negative predictive value (NPV) 94%. The decision tree predicted DHF with a Sn of 99%, Sp 12%, PPV 16%, and NPV 99%. Both tools performed well despite a switch in predominant dengue serotypes. PMID: 22049054 [PubMed - in process] (Source: The American Journal of Tropical Medicine and Hygiene)

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Neuroinvasive flavivirus infections

Reviews in Medical Virology — Tue, 01 Nov 2011 04:00:00 +0100

SUMMARYFlaviviruses, including Dengue, West Nile, Japanese encephalitis, and Tick‐borne encephalitis virus, are major emerging human pathogens, affecting millions of individuals worldwide. Many clinically important flaviviruses elicit CNS diseases in infected hosts, including traditional “hemorrhagic” viruses, such as Dengue. This review focuses on the epidemiology, symptomatology, neuropathology, and, specifically, neuropathogenesis of flavivirus‐induced human CNS disease. A detailed insight into specific factors priming towards neuroinvasive disease is of clear clinical significance, as well as importance to the development of antiviral therapies and identification of key mechanisms involved in the (re)emergence of specific flaviviruses, including potentially novel or previously ...

Mosquito-associated Dengue Virus, Key West, Florida, USA, 2010.

Emerging Infectious Diseases — Tue, 01 Nov 2011 04:00:00 +0100

Authors: Graham AS, Pruszynski CA, Hribar LJ, Demay DJ, Tambasco AN, Hartley AE, Fussell EM, Michael SF, Isern S Abstract To the Editor: Except for sporadic cases along the Texas-Mexico border, local transmission of dengue virus (DENV) has not occurred in the contiguous United States since 1946. In 2009, DENV was diagnosed in a vacationer to Key West, Florida (1). Subsequently, 25 other cases were reported that year, transmission was confirmed by detection of DENV serotype 1 (DENV-1) in local mosquitoes, and a random serosurvey showed evidence of recent DENV infection in 5.4% of Key West residents (1). Transmission continued in 2010, and an additional 63 cases were confirmed (2). We used PCR amplification and sequence analysis of virus identified from mosquito collections during 20...

New dengue virus type 1 genotype in colombo, sri lanka.

Emerging Infectious Diseases — Tue, 01 Nov 2011 04:00:00 +0100

Authors: Tissera HA, Ooi EE, Gubler DJ, Tan Y, Logendra B, Wahala WM, de Silva AM, Abeysinghe MR, Palihawadana P, Gunasena S, Tam CC, Amarasinghe A, Letson GW, Margolis HS, De Silva AD Abstract The number of cases and severity of disease associated with dengue infection in Sri Lanka has been increasing since 1989, when the first epidemic of dengue hemorrhagic fever was recorded. We identified a new dengue virus 1 strain circulating in Sri Lanka that coincided with the 2009 dengue epidemic. PMID: 22099096 [PubMed - in process] (Source: Emerging Infectious Diseases)

Sterile Mosquito Bred To Fight Dengue Fever Shows Promise In Field Trial

Health News from Medical News Today — Mon, 31 Oct 2011 17:00:00 +0100

A new study published in the journal Nature Biotechnology on 30 October finds that introducing genetically sterile mosquitoes into the wild shows promise as a way to help fight the dengue-carrying mosquito Aedes aegypti. The publication follows a presentation of the results at an annual meeting of the American Society of Tropical Medicine and Hygiene in Atlanta last November... (Source: Health News from Medical News Today)

Antiviral drugs: Dogfish shark chemical has broad-spectrum activity

Nature Reviews Drug Discovery — Mon, 31 Oct 2011 04:00:00 +0100

Nature Reviews Drug Discovery 10, 816 (2011). doi:10.1038/nrd3596 Author: Charlotte Harrison Zasloff et al. showed that squalamine, a compound first isolated from the dogfish shark and known to have antimicrobial properties, also has broad-spectrum antiviral activity against human pathogens. In vitro the compound was effective against dengue virus and hepatitis, and in vivo (Source: Nature Reviews Drug Discovery)

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Concerns Raised about Genetically Engineered Mosquitoes

NYT Health — Mon, 31 Oct 2011 03:17:32 +0100

Researchers have bred mosquitoes engineered to pass a lethal gene to their offspring, killing them before they reach adulthood. (Source: NYT Health)

GM mosquitoes show fever promise

BBC News | Health | UK Edition — Sun, 30 Oct 2011 20:56:54 +0100

A field study of genetically modified mosquitoes suggests they could be deployed against dengue fever and other tropical diseases. (Source: BBC News | Health | UK Edition)

Field performance of engineered male mosquitoes

Nature Biotechnology — Sun, 30 Oct 2011 04:00:00 +0100

We report data from the first open-field trial involving a strain of engineered mosquito. We demonstrated that genetically modified male mosquitoes, released across 10 hectares for a 4-week period, mated successfully with wild females and fertilized their eggs. These findings suggest the feasibility of this technology to control dengue by suppressing field populations of A. aegypti. (Source: Nature Biotechnology)

Clinicohematological Profile and Platelet Trends in Children with Dengue During 2010 Epidemic in North India

Indian Journal of Pediatrics — Sat, 29 Oct 2011 05:47:20 +0100

Conclusions This study showed shift to higher age of presentation, more number of dengue hemorrhagic fever and associated co-infections in children. The complications and mortality was low and platelet recovery time was not influenced by disease category. Content Type Journal ArticleCategory Original ArticlePages 1-5DOI 10.1007/s12098-011-0586-7Authors Hema Mittal, Department of Pediatrics, University College of Medical Sciences and Guru Tegh Bahadur Hospital, Delhi, IndiaM. M. A. Faridi, Department of Pediatrics, University College of Medical Sciences and Guru Tegh Bahadur Hospital, Delhi, IndiaShilpa Khanna Arora, Department of Pediatrics, University College of Medical Sciences and Guru Tegh Bahadur Hospital, Delhi, IndiaRahul Patil, Department of Pediatrics, Unive...

Single nucleotide polymorphism in the promoter region of the CD209 gene is associated with human predisposition to severe forms of tick-borne encephalitis.

Antiviral Research — Fri, 28 Oct 2011 04:00:00 +0100

Authors: Barkhash AV, Perelygin AA, Babenko VN, Brinton MA, Voevoda MI Abstract Tick-borne encephalitis virus (TBEV) is a neurotropic, positive-sense RNA virus of the genus Flavivirus (family Flaviviridae) which can cause a variety of clinical manifestations in humans. Previously the severity and outcome of dengue fever and hepatitis C (diseases caused by viruses from the family Flaviviridae) were associated with the rs4804803 single nucleotide polymorphism (SNP) located in the promoter region of the human CD209 gene. This gene encodes dendritic cell-specific ICAM3-grabbing nonintegrin (DC-SIGN), a C-type lectin pathogen-recognition receptor expressed on the surface of dendritic cells and some types of macrophages. In the current study, a possible association between two SNPs in th...

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Big Pharma Giving Away Drug Patents To Help Cure Tropical Disease

Scientific American - Official RSS Feed — Thu, 27 Oct 2011 12:22:00 +0100

By Ariel SchwartzBy offering up their drugs for free to developing countries, drug companies hope to make inroads into new markets, and prevent a few diseases along the way. Intellectual property is crucial for pharmaceutical companies to survive; without it, their pricey blockbuster drugs can be replaced with cheap generics. And yet, big companies like AstraZeneca, Novartis, GlaxoSmithKline, Pfizer, Sanofi, and Merck are willingly putting some of their intellectual property information in a public database . The pharmaceutical industry hasn't gone crazy--it's just participating in an initiative that aims to treat neglected tropical diseases. WIPO Re:Search , a collaboration between The World Intellectual Property Organization, BIO Ventures For Global Health, pharmaceutical giants, nonprof...

Estimation of dengue virus IgM persistence using regression analysis.

Clinical and Vaccine Immunology — Wed, 26 Oct 2011 04:00:00 +0100

Authors: Prince HE, Matud JL Abstract Dengue virus IgM persistence was estimated using follow-up sera from 98 patients (60 primary, 38 secondary infections) whose first specimen IgM index was strongly positive, suggesting recent disease onset. Regression analysis of follow-up IgM index versus days between samples yielded a trendline that reached the cut-point index (1.10) at 179 days for the primary group versus 139 days for the secondary group. This difference reflected significantly higher first-sample IgM indices in primary versus secondary infection, rather than differences in IgM decay rates. PMID: 22030368 [PubMed - as supplied by publisher] (Source: Clinical and Vaccine Immunology)

Should Scientists Use Genetically Modified Insects to Fight Disease?

Scientific American Topic - Biotechnology — Mon, 24 Oct 2011 15:00:00 +0100

In the November 2011 issue of Scientific American, author Bijal Trivedi looks at the ongoing controversies surrounding the use of genetically modified mosquitoes to fight dengue fever. We asked biologist Mark Q. Benedict and Helen Wallace, the director of GeneWatch UK , to illuminate the issues surrounding the release of genetically modified insects into the wild. Genetically Modified Mosquitoes Could Be an Important Tool in the Fight against Disease [More] (Source: Scientific American Topic - Biotechnology)

Green Synthesis of Silver Nanoparticles for the Control of Mosquito Vectors of Malaria, Filariasis, and Dengue

Vector-Borne and Zoonotic Diseases — Mon, 24 Oct 2011 13:41:48 +0100

Vector-Borne and Zoonotic Diseases , Vol. 0, No. 0. (Source: Vector-Borne and Zoonotic Diseases)

A Method for Accurate Inference of Population Size from Serially Sampled Genealogies Distorted by Selection

Molecular Biology and Evolution — Sun, 23 Oct 2011 04:00:00 +0100

The serial coalescent extends traditional coalescent theory to include genealogies in which not all individuals were sampled at the same time. Inference in this framework is powerful because population size and evolutionary rate may be estimated independently. However, when the sequences in question are affected by selection acting at many sites, the genealogies may differ significantly from their neutral expectation, and inference of demographic parameters may become inaccurate. I demonstrate that this inaccuracy is severe when the mutation rate and strength of selection are jointly large, and I develop a new likelihood calculation that, while approximate, improves the accuracy of population size estimates. When used in a Bayesian parameter estimation context, the new calculation allows f...

Transfusion transmission risk of dengue viruses in an endemic area

ISBT Science Series — Sat, 22 Oct 2011 23:25:54 +0100

It is believed that dengue virus (DENV) is transfusion transmittable, only a few transfusion associated cases were reported so far in spite of at least 50 million dengue infections occur globally each year. The equation for calculating DENV transfusion transmission probability was proposed following the West Nile Virus model. In consideration of reported case number, population size in the region around the designated cases, symptomatic infection rate, blood donation rate, and mosquito biological characteristics together, a relative low rate of DENV transmittable donations was presumed in a low‐grade endemic area. Both the apparent clinical presentation and the relative short viremia period of DENV infection prevent dengue viruses from being a highly potential transfusion transmittable a...

Dengue virus surveillance in Singapore reveals high viral diversity through multiple introductions andinsituevolution

Journal of Dentistry — Sat, 22 Oct 2011 20:32:51 +0100

This study aims to understand the dynamics of dengue viruses in cosmopolitan Singapore. Envelope protein gene sequences of all four dengue serotypes (DENV-1 – DENV-4) obtained from human sera in Singapore (2008-2010) revealed that constant viral introductions andin situevolution contribute to viral diversity in Singapore and play important roles in shaping the epidemiology of dengue in the island state. The diversity of dengue viruses reported here could be a reflection of the on-going dengue situation in the region given Singapore’s location in a dengue hyperendemic region and its role as the regional hub for travels and trade. Though cosmopolitan genotype of DENV-2 has remained as the predominant strain circulating in Singapore, we uncovered evidence ofinsituevolution which could pos...

Mechanisms Used By Wolbachia Bacteria To Control Vectors Of Deadly Diseases

Health News from Medical News Today — Sat, 22 Oct 2011 07:00:00 +0100

Researchers at Boston University have made discoveries that provide the foundation towards novel approaches to control insects that transmit deadly diseases such as dengue fever and malaria through their study of the Wolbachia bacteria. Their findings have been published in the current issue of Science Express, an online publication of selected papers in advance of the print edition of Science, the main journal of the American Association for the Advancement of Science (AAAS)... (Source: Health News from Medical News Today)