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- IFITM proteins are incorporated onto HIV-1 virion particles and negatively imprint their infectivity.
Tartour K, Appourchaux R, Gaillard J, et al. IFITM proteins are incorporated onto HIV-1 virion particles and negatively imprint their infectivity. [JOURNAL ARTICLE]Retrovirology 2014 Nov 25; 11(1):103.BackgroundInterferon induced transmembrane proteins 1, 2 and 3 (IFITMs) belong to a family of highly related antiviral factors that have been shown to interfere with a large spectrum of viruses including Filoviruses, Coronaviruses, Influenza virus, Dengue virus and HIV-1. In all these cases, the reported mechanism of antiviral inhibition indicates that the pool of IFITM proteins present in target cells blocks incoming viral particles in endosomal vesicles where they are subsequently degraded.ResultsIn this study, we describe an additional mechanism through which IFITMs block HIV-1. In virus-producing cells, IFITMs coalesce with forming virions and are incorporated into viral particles. Expression of IFITMs during virion assembly leads to the production of virion particles of decreased infectivity that are mostly affected during entry in target cells. This mechanism of inhibition is exerted against different retroviruses and does not seem to be dependent on the type of Envelope present on retroviral particles.ConclusionsThe results described here identify a novel mechanism through which IFITMs affect HIV-1 infectivity during the late phases of the viral life cycle. Put in the context of data obtained by other laboratories, these results indicate that IFITMs can target HIV at two distinct moments of its life cycle, in target cells as well as in virus-producing cells. These results raise the possibility that IFITMs could similarly affect distinct steps of the life cycle of a number of other viruses.
- Flavivirus-Mosquito Interactions.
Huang YJ, Higgs S, Horne KM, et al. Flavivirus-Mosquito Interactions. [REVIEW]Viruses 2014; 6(11):4703-4730.The Flavivirus genus is in the family Flaviviridae and is comprised of more than 70 viruses. These viruses have a broad geographic range, circulating on every continent except Antarctica. Mosquito-borne flaviviruses, such as yellow fever virus, dengue virus serotypes 1-4, Japanese encephalitis virus, and West Nile virus are responsible for significant human morbidity and mortality in affected regions. This review focuses on what is known about flavivirus-mosquito interactions and presents key data collected from the field and laboratory-based molecular and ultrastructural evaluations.
- The revised dengue fever classification in German travelers: clinical manifestations and indicators for severe disease.
Hoffmeister B, Suttorp N, Zoller T The revised dengue fever classification in German travelers: clinical manifestations and indicators for severe disease. [JOURNAL ARTICLE]Infection 2014 Nov 25.The number of dengue cases imported to Germany has increased significantly in recent years. Among returning travelers, dengue is now a frequent cause of hospitalization. The aim of this study was to determine the proportion of patients with severe disease hospitalized in a European, non-endemic country applying the revised 2009 WHO classification system and to determine predictors of severe disease.A retrospective single-center analysis of clinical data from 56 patients, 31 (55 %) women and 25 (45 %) men, between 14 and 70 years of age treated in a tertiary care hospital between 1996 and 2010 was conducted.Thirty-nine patients (69.6 %) presented with dengue fever without warning signs, 11 (19.6 %) with warning signs and 6 (10.7 %) with signs for severe dengue fever. Two patients (4 %) developed dengue shock syndrome. Non-European descent (p = 0.001), plasma protein level <6.5 mg/dl (p = 0.001), platelets <30/nl (p = 0.017) and activated partial thromboplastin time (aPTT) >44 s (p = 0.003) were associated with severe disease.A significant proportion of patients hospitalized with symptomatic imported dengue fever in Germany have evidence of severe disease. Simple routine laboratory parameters such as complete blood count, plasma protein level and aPTT are helpful tools for identifying adult patients at risk for severe disease.
- Use of simple clinical and laboratory predictors to differentiate influenza from dengue and other febrile illnesses in the emergency room.
Huang SY, Lee IK, Wang L, et al. Use of simple clinical and laboratory predictors to differentiate influenza from dengue and other febrile illnesses in the emergency room. [JOURNAL ARTICLE]BMC Infect Dis 2014 Nov 25; 14(1):623.BackgroundClinical differentiation of influenza from dengue and other febrile illnesses (OFI) is difficult, and available rapid diagnostic tests have limited sensitivity.MethodsWe conducted a retrospective study to compare clinical and laboratory findings between (i) influenza and dengue and (ii) influenza and OFI.ResultsOf 849 enrolled patients, the mean time between illness onset and hospital presentation was 1.7, 3.7, and 3 days for influenza, dengue, and OFI, respectively. Among pediatric patients (¿18 years) (445 influenza, 24 dengue, and 130 OFI), we identified absence of rashes, no leukopenia, and no marked thrombocytopenia (platelet counts <100¿×¿109 cells/L) as predictors to distinguish influenza from dengue, whereas rhinorrhea, malaise, sore throat, and mild thrombocytopenia (platelet counts 100¿149¿×¿109/L) were predictors that differentiated influenza from OFI. Among adults (>18 years) (81 influenza, 124 dengue, and 45 OFI), no leukopenia and no marked thrombocytopenia distinguished influenza from dengue, while rhinorrhea and malaise differentiated influenza from OFI. A diagnostic algorithm developed to distinguish influenza from dengue using rash, leukopenia, and marked thrombocytopenia showed >90% sensitivity to identify influenza in pediatric patients.ConclusionsThis study identified simple clinical and laboratory parameters that can assist clinicians to distinguish influenza from dengue and OFI. These findings may help clinicians diagnose influenza and facilitate appropriate management of affected patients, particularly in resource-poor settings.
- The laboratory-confirmed dengue fever and chikungunya fever cases at the Narita Airport Quarantine Station in 2013.
Furuichi M, Makie T, Honma Y, et al. The laboratory-confirmed dengue fever and chikungunya fever cases at the Narita Airport Quarantine Station in 2013. [JOURNAL ARTICLE]Jpn J Infect Dis 2014 Nov 25.Fourteen patients were laboratory-confirmed as cases of imported-infectious diseases at the Narita Airport Quarantine Station in 2013. Blood tests were performed on 283 subjects with suspected of imported-infectious diseases. Of these, 11 were diagnosed as having dengue fever (dengue) and 3 as having chikungunya fever (chikungunya) by real-time RT-PCR. The possible countries from which the dengue virus infection was contracted were Thailand, Laos, Sri Lanka, and some other countries also in Southeast Asia and South Asia. The three chikungunya were also in returnees from Southeast Asia. Most of the patients with dengue had a fever of over 38 ℃. Other symptoms were generalized fatigue, dull headache, pain behind the eyes, arthralgia and digestive symptoms. The Subjects had been unaware of any mosquito bites in 4 cases. The information from and results of the confirmed cases showed that it is important to consider the destination as well as the clinical symptoms, independent of whether the subjects were aware of mosquito bites or not. The detection rate of chikungunya at the Quarantine station was higher than that of dengue in all reported cases in Japan.
- Dengue Virus 4 (DENV-4) re-emerges after 30 years in Brazil: Co-circulation of DENV 2, DENV-3 and DENV-4 in Bahia.
Soares Campos G, Cruz Oliveira Pinho A, Jose de Freitas Brandão C, et al. Dengue Virus 4 (DENV-4) re-emerges after 30 years in Brazil: Co-circulation of DENV 2, DENV-3 and DENV-4 in Bahia. [JOURNAL ARTICLE]Jpn J Infect Dis 2014 Nov 25.Dengue fever (DF), is a mosquito-borne viral disease of great concern in tropical and subtropical regions of the world. One important cause of the increase in DF is rapid development and urbanization, which led to proliferation of the Aedes aegyptis, mosquito, responsible for transmission of the illness. The surveillance of Dengue Virus (DENV) infection up until 2010 in Brazil has predominantly shown the presence of DENV-1, DENV-2 and DENV-3; however, this study reports the reappearance of DENV-4 for the first time in 30 years. The serum samples collected from individuals (n=214) exhibiting fever and muscular pain in Bahia, Brazil during 2011-2012 submitted to RT-PCR/Nested-PCR revealed 82% of the samples positive to DENV-4, mostly in older age groups with serological pattern of primary infection. The co-circulation of multiple DENV serotypes in the same city places the population at risk for a fatal form of the disease. Therefore, with the increasing incidence of severe dengue fever cases, the early diagnosis confirmation will be a priority for the Brazilian public health.
- Spatiotemporal clustering, climate periodicity, and social-ecological risk factors for dengue during an outbreak in Machala, Ecuador, in 2010.
Stewart-Ibarra AM, Muñoz AG, Ryan SJ, et al. Spatiotemporal clustering, climate periodicity, and social-ecological risk factors for dengue during an outbreak in Machala, Ecuador, in 2010. [JOURNAL ARTICLE]BMC Infect Dis 2014 Nov 25; 14(1):610.AbstractPublisher Full TextBackgroundDengue fever, a mosquito-borne viral disease, is a rapidly emerging public health problem in Ecuador and throughout the tropics. However, we have a limited understanding of the disease transmission dynamics in these regions. Previous studies in southern coastal Ecuador have demonstrated the potential to develop a dengue early warning system (EWS) that incorporates climate and non-climate information. The objective of this study was to characterize the spatiotemporal dynamics and climatic and social-ecological risk factors associated with the largest dengue epidemic to date in Machala, Ecuador, to inform the development of a dengue EWS.MethodsThe following data from Machala were included in analyses: neighborhood-level georeferenced dengue cases, national census data, and entomological surveillance data from 2010; and time series of weekly dengue cases (aggregated to the city-level) and meteorological data from 2003 to 2012. We applied LISA and Moran¿s I to analyze the spatial distribution of the 2010 dengue cases, and developed multivariate logistic regression models through a multi-model selection process to identify census variables and entomological covariates associated with the presence of dengue at the neighborhood level. Using data aggregated at the city-level, we conducted a time-series (wavelet) analysis of weekly climate and dengue incidence (2003-2012) to identify significant time periods (e.g., annual, biannual) when climate co-varied with dengue, and to describe the climate conditions associated with the 2010 outbreak.ResultsWe found significant hotspots of dengue transmission near the center of Machala. The best-fit model to predict the presence of dengue included older age and female gender of the head of the household, greater access to piped water in the home, poor housing condition, and less distance to the central hospital. Wavelet analyses revealed that dengue transmission co-varied with rainfall and minimum temperature at annual and biannual cycles, and we found that anomalously high rainfall and temperatures were associated with the 2010 outbreak.ConclusionsOur findings highlight the importance of geospatial information in dengue surveillance and the potential to develop a climate-driven spatiotemporal prediction model to inform disease prevention and control interventions. This study provides an operational methodological framework that can be applied to understand the drivers of local dengue risk.
- Internal travel and risk of dengue transmission in Colombia.
Chaparro PE, de la Hoz F, Lozano Becerra JC, et al. Internal travel and risk of dengue transmission in Colombia. [Journal Article]Rev Panam Salud Publica 2014 Sep; 36(3):197-200.Human behavior plays a key role in the dynamics of dengue transmission. However, research on the relationship between human movement and dengue transmission within endemic countries is limited. From January 2008 to December 2011, the authors of this study conducted a retrospective analysis of imported dengue infections in Bogotá, Colombia. Bogotá is a vector-transmission-free city that is also the capital district and most populated municipality in Colombia. The study revealed that 1) Bogotá inhabitants acquired dengue infection in diverse localities throughout the country but the largest proportion of cases (35.6%) were contracted at popular tourist destinations in dengue-endemic areas near Bogotá (<200-km radius from city limits), and 2) the number of imported dengue cases increased after major holidays, a transmission pattern not seen in dengue-endemic areas, where disease incidence correlates with rainy periods. It is therefore recommended that physicians consider the effect of travel when diagnosing their patients' illnesses, especially outside dengue-endemic areas where diagnosis of the disease can be challenging due to its nonspecific symptoms. The study also showed that analysis of dengue cases imported to regions free of vector transmission can generate an evidence-based model for characterizing the impact of human movement on the spread of diseases like dengue in countries where they are endemic.
- [Environmental pollution, climate variability and climate change: a review of health impacts on the peruvian population].
Gonzales GF, Zevallos A, Gonzales-Castañeda C, et al. [Environmental pollution, climate variability and climate change: a review of health impacts on the peruvian population]. [English Abstract, Journal Article]Rev Peru Med Exp Salud Publica 2014 Sep; 31(3):547-56.This article is a review of the pollution of water, air and the effect of climate change on the health of the Peruvian population. A major air pollutant is particulate matter less than 2.5 μ (PM 2.5). In Lima, 2,300 premature deaths annually are attributable to this pollutant. Another problem is household air pollution by using stoves burning biomass fuels, where excessive indoor exposure to PM 2.5 inside the household is responsible for approximately 3,000 annual premature deaths among adults, with another unknown number of deaths among children due to respiratory infections. Water pollution is caused by sewage discharges into rivers, minerals (arsenic) from various sources, and failure of water treatment plants. In Peru, climate change may impact the frequency and severity of El Niño Southern Oscillation (ENSO), which has been associated with an increase in cases of diseases such as cholera, malaria and dengue. Climate change increases the temperature and can extend the areas affected by vector-borne diseases, have impact on the availability of water and contamination of the air. In conclusion, Peru is going through a transition of environmental risk factors, where traditional and modern risks coexist and infectious and chronic problems remain, some of which are associated with problems of pollution of water and air.
- Evaluation of commercially available serologic diagnostic tests for chikungunya virus.
Prat CM, Flusin O, Panella A, et al. Evaluation of commercially available serologic diagnostic tests for chikungunya virus. [Journal Article]Emerg Infect Dis 2014 Dec; 20(12):2129-32.Chikungunya virus (CHIKV) is present or emerging in dengue virus-endemic areas. Infections caused by these viruses share some common signs/symptoms, but prognosis, patient care, and persistent symptoms differ. Thus, accurate diagnostic methods are essential for differentiating the infections. We evaluated 4 CHIKV serologic diagnostic tests, 2 of which showed poor sensitivity and specificity.