eastern equine encephalomyelitis in panama: the epidemiology of the 1973 late june 1973, a small outbreak of equine encephalitis caused by eastern equine encephalomyelitis (eee) virus occurred in the republic of panama. at least 100 horses were affected by the disease and 40 died. more than 1,700 human sera were obtained from areas of virus activity but no serological evidence for infection was found. four isolates of eee virus were recovered, one of which was from a small pool of culex taeniopus mosquitoes. serologic studies of infected horses and classification ...19807352621
molecular epidemiology of group c viruses (bunyaviridae, orthobunyavirus) isolated in the date, no molecular studies on group c viruses (bunyaviridae, orthobunyavirus) have been published. we determined the complete small rna (srna) segment and partial medium rna segment nucleotide sequences for 13 group c members. the full-length srna sequences ranged from 915 to 926 nucleotides in length, and revealed similar organization in comparison with other orthobunyaviruses. based on the 705 nucleotides of the n gene, group c members were distributed into three major phylogenetic groups, ...200516051848
evolutionary patterns of eastern equine encephalitis virus in north versus south america suggest ecological differences and taxonomic revision.the eastern equine encephalitis (eee) complex consists of four distinct genetic lineages: one that circulates in north america (na eeev) and the caribbean and three that circulate in central and south america (sa eeev). differences in their geographic, pathogenic, and epidemiologic profiles prompted evaluation of their genetic diversity and evolutionary histories. the structural polyprotein open reading frames of all available sa eeev and recent na eeev isolates were sequenced and used in evolut ...201019889755
blood feeding patterns of mosquitoes: random or structured?abstract:201020205866
vector competence of culex (melanoconion) taeniopus for equine-virulent subtype ie strains of venezuelan equine encephalitis virus.the mosquito culex (melanoconion) taeniopus is a proven vector of enzootic venezuelan equine encephalitis virus (veev) subtype ie in central america. it has been shown to be highly susceptible to infection by this subtype, and conversely to be highly refractory to infection by other veev subtypes. during the 1990s in southern coastal mexico, two vee epizootics in horses were attributed to subtype ie veev. these outbreaks were associated with veev strains with an altered infection phenotype for t ...201020519599
tissue barriers to arbovirus infection in mosquitoes.arthropod-borne viruses (arboviruses) circulate in nature between arthropod vectors and vertebrate hosts. arboviruses often cause devastating diseases in vertebrate hosts, but they typically do not cause significant pathology in their arthropod vectors. following oral acquisition of a viremic bloodmeal from a vertebrate host, the arbovirus disease cycle requires replication in the cellular environment of the arthropod vector. once the vector has become systemically and persistently infected, the ...201526184281
vector-borne transmission imposes a severe bottleneck on an rna virus population.rna viruses typically occur in genetically diverse populations due to their error-prone genome replication. genetic diversity is thought to be important in allowing rna viruses to explore sequence space, facilitating adaptation to changing environments and hosts. some arboviruses that infect both a mosquito vector and a mammalian host are known to experience population bottlenecks in their vectors, which may constrain their genetic diversity and could potentially lead to extinction events via mu ...201223028310
rapid selection against arbovirus-induced apoptosis during infection of a mosquito vector.millions of people are infected each year by arboviruses (arthropod-borne viruses) such as chikungunya, dengue, and west nile viruses, yet for reasons that are largely unknown, only a relatively small number of mosquito species are able to transmit arboviruses. understanding the complex factors that determine vector competence could facilitate strategies for controlling arbovirus infections. apoptosis is a potential antiviral defense response that has been shown to be important in other virus-ho ...201525713358
arboviral bottlenecks and challenges to maintaining diversity and fitness during mosquito transmission.the term arbovirus denotes viruses that are transmitted by arthropods, such as ticks, mosquitoes, and other biting arthropods. the infection of these vectors produces a certain set of evolutionary pressures on the virus; involving migration from the midgut, where the blood meal containing the virus is processed, to the salivary glands, in order to transmit the virus to the next host. during this process the virus is subject to numerous bottlenecks, stochastic events that significantly reduce the ...201425341663
epidemiology of emergent madariaga encephalitis in a region with endemic venezuelan equine encephalitis: initial host studies and human cross-sectional study in darien, panama.neurotropic arboviral infections are an important cause of encephalitis. a zoonotic, vector-borne alphavirus, madariaga virus (madv; formerly known as south american eastern equine encephalitis virus), caused its first documented human outbreak in 2010 in darien, panama, where the genetically similar venezuelan equine encephalitis virus (veev) is endemic. we report the results of a seroprevalence survey of animals and humans, illustrating contrasting features of madv and veev ecology and epidemi ...201627101567
west nile virus ecology in a tropical ecosystem in guatemala.west nile virus ecology has yet to be rigorously investigated in the caribbean basin. we identified a transmission focus in puerto barrios, guatemala, and established systematic monitoring of avian abundance and infection, seroconversions in domestic poultry, and viral infections in mosquitoes. west nile virus transmission was detected annually between may and october from 2005 to 2008. high temperature and low rainfall enhanced the probability of chicken seroconversions, which occurred in both ...201223149586
insect-specific viruses detected in laboratory mosquito colonies and their potential implications for experiments evaluating arbovirus vector competence.recently, there has been a dramatic increase in the detection and characterization of insect-specific viruses in field-collected mosquitoes. evidence suggests that these viruses are ubiquitous in nature and that many are maintained by vertical transmission in mosquito populations. some studies suggest that the presence of insect-specific viruses may inhibit replication of a super-infecting arbovirus, thus altering vector competence of the mosquito host. accordingly, we screened our laboratory mo ...201425510714
diversity of mosquito vectors (diptera: culicidae) in caxiuanã, pará, brazil.this paper presents a study based on ecological parameters represented by diversity and richness indices applied in a community of mosquitoes (diptera: culicidae), at the national forest of caxiuanã, melgaço municipality, state of pará, in the brazilian amazon. a total of 25,433 specimens of culicids were collected in the study, from five field collection periods, over 10 months, between 2005 and 2006. specimens were collected in four heights of the forest (ground level, 8 m, 16 m, and 30 m-cano ...201222997514
diversity of mosquitoes and the aquatic insects associated with their oviposition sites along the pacific coast of mexico.the abundance, richness and diversity of mosquitoes and aquatic insects associated with their oviposition sites were surveyed along eight states of the pacific coast of mexico. diversity was estimated using the shannon index (h'), similarity measures and cluster analysis.201424450800
dna barcodes and evidence of cryptic diversity of anthropophagous mosquitoes in quintana roo, mexico.culicidae mosquitoes are potential vectors of pathogens that affect human health. the correct species identification, as well as the discovery and description of cryptic species, is important in public health for the control and management of specific vectors. in the present study, the diversity of anthropophagous mosquitoes in quintana roo, at the border between mexico and belize, was evaluated using morphological and molecular data (coi-dna barcoding). a total of 1,413 adult female specimens w ...201931031936
entomological studies at an enzootic venezuelan equine encephalitis virus focus in guatemala, 1977-1980.the ecology of several potential mosquito vectors of venezuelan equine encephalitis (vee) alphavirus was studied in an enzootic focus of that virus on the pacific coast of guatemala over a four-year period. four species-culex taeniopus, mansonia titillans, culex nigripalpus and aedes taeniorhynchus-were most prevalent during the wet season when transmission normally occurs. however, only cx. taeniopus yielded vee virus. the bloodfeeding patterns of these species revealed that ae. taeniorhynchus ...19862873752
tonate and guama-group viruses isolated from mosquitoes in both a savannah and coastal area in surinam.isolation of arboviruses was attempted from october 1972 till the end of 1973 from mosquitoes caught in both a savannah forest near powaka and a coastal area near "fernandesweg" in surinam. two types of arbovirus were isolated: eleven strains of tonate and ten strains of guama-group. in the savannah area ten strains of tonate and five of guama-group were isolated, whereas in the coastal area the numbers were one and five, respectively. all strains in the savannah area were isolated from pools of ...197941349
mosquito bottlenecks alter viral mutant swarm in a tissue and time-dependent manner with contraction and expansion of variant positions and diversity.viral diversity is theorized to play a significant role during virus infections, particularly for arthropod-borne viruses (arboviruses) that must infect both vertebrate and invertebrate hosts. to determine how viral diversity influences mosquito infection and disseminationculex taeniopusmosquitoes were infected with the venezuelan equine encephalitis virus endemic strain 68u201. bodies and legs/wings of the mosquitoes were collected individually and subjected to multi-parallel sequencing. virus ...201829479479
candidate vectors and rodent hosts of venezuelan equine encephalitis virus, chiapas, 2006-2007.enzootic venezuelan equine encephalitis virus (veev) has been known to occur in mexico since the 1960s. the first natural equine epizootic was recognized in chiapas in 1993 and since then, numerous studies have characterized the etiologic strains, including reverse genetic studies that incriminated a specific mutation that enhanced infection of epizootic mosquito vectors. the aim of this study was to determine the mosquito and rodent species involved in enzootic maintenance of subtype ie veev in ...201122144461
vector competence of mexican and honduran mosquitoes (diptera: culicidae) for enzootic (ie) and epizootic (ic) strains of venezuelan equine encephalomyelitis virus.experimental studies evaluated the vector competence of ochlerotatus taeniorhynchus (wiedemann), culex cancer theobald, culex pseudes (dyar and knab), culex taeniopus dyar and knab, and a culex (culex) species, probably culex quinquefasciatus say, and culex nigripalpus theobald from chiapas, mexico, and tocoa, honduras, for epizootic (ic) and enzootic (ie) strains of venezuelan equine encephalomyelitis (vee) virus. culex pseudes was highly susceptible to infection with both the ic and ie strains ...200312943109
demographics of natural oral infection of mosquitos by venezuelan equine encephalitis virus.the within-host diversity of virus populations can be drastically limited during between-host transmission, with primary infection of hosts representing a major constraint to diversity maintenance. however, there is an extreme paucity of quantitative data on the demographic changes experienced by virus populations during primary infection. here, the multiplicity of cellular infection (moi) and population bottlenecks were quantified during primary mosquito infection by venezuelan equine encephali ...201525589654
Analysis of intrahost variation in venezuelan equine encephalitis virus reveals repeated deletions in the 6-kilodalton protein gene.RNA viruses exist as a spectrum of mutants that is generated and maintained during replication within the host. Consensus sequencing overlooks minority genotypes present in the viral sample that may impact the population's phenotype. In-depth sequencing of an original field isolate of subtype IE Venezuelan equine encephalitis virus (VEEV) demonstrated the presence of multiple deletions within the 6,000-molecular-weight (6K) protein gene. Using in vitro and in vivo experiments, similar deletions ...201121715498
Displaying items 1 - 22 of 22