A simulation study of effects of host availability on the bite rate of Aedes albopictus (Skuse) (Diptera: Culicidae) and the risk of dengue outbreaks in non-endemic areas.

A simulation study of effects of host availability on the bite rate of Aedes albopictus (Skuse) (Diptera: Culicidae) and the risk of dengue outbreaks in non-endemic areas. Jpn J Infect Dis. 2017 Dec 26;: Authors: Sunahara T Abstract Aedes albopictus is an important vector of dengue fever and tends to ambush blood host in a single place. Thus, host contact frequency may affect the bite rate and risk of disease outbreak, although no studies have examined these parameters. The present study used a simple model to clarify the fundamental relationship between host availability, bite rate, and risk of dengue outbreaks in non-endemic areas. A hypothetical isolated mosquito population was divided into "ambush" and "resting" subpopulations, and human hosts were modeled as visiting mosquito population at constant intervals. A single infectious human who only visited the mosquito population once was responsible for mosquito infections and the secondary infections among humans who subsequently visit the area after the incubation period. The results confirmed that the bite rate per host increased with decreasing host availability. The number of secondary infections among hosts exhibited a unimodal relationship with the frequency of host visits, with a maximum value at host visits every 24 h. Furthermore, when host availability was not very low, the bite rate was a good indicator of the potential risk of dengue outbreaks. Therefore, human-bait-swee...
Source: Japanese Journal of Infectious Diseases - Category: Infectious Diseases Authors: Tags: Jpn J Infect Dis Source Type: research

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ConclusionsThe paper describes a strategy that applies newspaper as proxies to monitor outbreaks of infectious diseases and to study the epidemiology. It has potential applicability in some developing countries and regions with relatively poor medical infrastructures and records. Clearly, large national newspapers in India provide a better source of information on diseases than international outlets. This approach has potential with selected diseases in a few selected countries. Article numbers internationally appear to vary in proportion to the perceived health impact.Graphical abstract
Source: Journal of Biomedical Informatics - Category: Information Technology Source Type: research
Publication date: Available online 16 December 2019Source: Antiviral ResearchAuthor(s): Michael W. Gaunt, Duane J. Gubler, John H.-O. Pettersson, Goro Kuno, Annelies Wilder-Smith, Xavier de Lamballerie, Ernest A. Gould, Andrew K. FalconarAbstractSporadic human Zika virus (ZIKV) infections have been recorded in Africa and Asia since the 1950s. Major epidemics occurred only after ZIKV emerged in the Pacific islands and spread to the Americas. Specific biological determinants of the explosive epidemic nature of ZIKV have not been identified. Phylogenetic studies revealed incongruence in ZIKV placement in relation to Aedes-bor...
Source: Antiviral Therapy - Category: Virology Source Type: research
On 1 May 2019, in response to increasing numbers of dengue fever cases in Pakistan and India, health authorities in Afghanistan heightened monitoring for the disease. As part of this increased vigilance, the Central Public Health Laboratory (CPHL) in Kabul began to broaden its investigation for possible cases of the disease, such as reviewing samples that tested negative for Crimean-Congo Hemorrhagic Fever (CCHF) to see if they were positive for dengue. The laboratory performed differential diagnosis and tests on 40 samples that had tested negative for Crimean-Congo Hemorrhagic Fever (CCHF). Between 1 October to 4 December...
Source: WHO Disease Outbreaks - Category: Infectious Diseases Tags: news Source Type: news
Abstract Sporadic human Zika virus (ZIKV) infections have been recorded in Africa and Asia since the 1950s. Major epidemics occurred only after ZIKV emerged in the Pacific islands and spread to the Americas. Specific biological determinants of the explosive epidemic nature of ZIKV have not been identified. Phylogenetic studies revealed incongruence in ZIKV placement in relation to Aedes-borne dengue viruses (DENV) and Culex-borne flaviviruses. We hypothesized that this incongruence reflects interspecies recombination resulting in ZIKV evasion of cross-protective T-cell immunity. We investigated ZIKV phylogenetic i...
Source: Antiviral Research - Category: Virology Authors: Tags: Antiviral Res Source Type: research
Dengue virus (DENV) infection is widespread in the tropics and subtropics, and the main vector of transmission is the Aedes aegypti mosquito, although Aedes albopictus may also be a vector. In countries where A. aegypti and/or A. albopictus are present, DENV will either be circulating or can be introduced by viremic travellers from endemic areas.
Source: International Journal of Infectious Diseases - Category: Infectious Diseases Authors: Source Type: research
Abstract Flaviviruses are group of single stranded RNA viruses that cause severe endemic infection and epidemics on a global scale. It presents a significant health impact worldwide and the viruses have the potential to emerge and outbreak in a non-endemic geographical region. Effective vaccines for prophylaxis are only available for several flaviviruses such as Yellow Fever virus, Tick-borne Encephalitis Virus, Dengue Virus and Japanese Encephalitis Virus and there is no antiflaviviral agent being marketed. This review discusses the flavivirus genome, replication cycle, epidemiology, clinical presentation and pat...
Source: Virus Research - Category: Virology Authors: Tags: Virus Res Source Type: research
by Elliott F. Miot, Fabien Aubry, St éphanie Dabo, Ian H. Mendenhall, Sébastien Marcombe, Cheong H. Tan, Lee C. Ng, Anna-Bella Failloux, Julien Pompon, Paul T. Brey, Louis Lambrechts The case-fatality rate of yellow fever virus (YFV) is one of the highest among arthropod-borne viruses (arboviruses). Although historically, the Asia-Pacific region has remained free of YFV, the risk of introduction has never been higher due to the increasing influx of people from endemic regions and the recent outbreaks in Africa and South America. Singapore is a global hub for trade and tourism and therefore at high risk for Y...
Source: PLoS Neglected Tropical Diseases - Category: Tropical Medicine Authors: Source Type: research
lmair Flaviviruses are the most medically relevant group of arboviruses causing a wide range of diseases in humans and are associated with high mortality and morbidity, as such posing a major health concern. Viruses belonging to this family can be endemic (e.g., dengue virus), but can also cause fulminant outbreaks (e.g., West Nile virus, Japanese encephalitis virus and Zika virus). Intense research efforts in the past decades uncovered shared fundamental strategies used by flaviviruses to successfully replicate in their respective hosts. However, the distinct features contributing to the specific host and tissue tropi...
Source: Viruses - Category: Virology Authors: Tags: Review Source Type: research
In recent years, public health threats due to Zika virus (ZIKV) and Ebola virus have increased awareness among the ophthalmic community regarding the visual effect of ocular sequelae identified in association with these emerging infectious diseases. Yellow fever virus (YFV), deemed the “original viral hemorrhagic fever,” resides in the Flavivirus family, which includes other mosquito-borne illnesses, including Dengue (DENV), West Nile (WNV), and ZIKV. Forty-seven countries in Africa (34 [72.3%]) and Central and South America (13 [27.7%]) are endemic for, or have regions endemi c for, YFV, underscoring its globa...
Source: JAMA Ophthalmology - Category: Opthalmology Source Type: research
Publication date: Available online 29 August 2019Source: Molecular Phylogenetics and EvolutionAuthor(s): Ricardo Durães-Carvalho, Louisa F. Ludwig-Begall, Marco Salemi, Roberto D. Lins, Ernesto T.A. MarquesAbstractDengue (DENV) and Zika (ZIKV) viruses are antigenically and evolutionarily related; immunological cross-reactions between them have been associated to both cross-protection and infection-enhanced mechanisms. Here, DENV-1-4 and ZIKV were investigated through Bayesian coalescent-based approaches and selection-driven Darwinian evolution methods using robust datasets. Our findings show that both DENV and ZIKV,...
Source: Molecular Phylogenetics and Evolution - Category: Molecular Biology Source Type: research
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