scholarly journals EVALUATION OF MULTIPLE TRAP TYPES FOR THE CAPTURE OF VECTOR MOSQUITOES OF EASTERN EQUINE ENCEPHALITIS VIRUS IN SAINT JOHNS COUNTY, FLORIDA

2021 ◽  
Vol 66 (1) ◽  
pp. 11-19
Author(s):  
Daniel Dixon
Keyword(s):  
Mosquito Species ◽  
Light Trap ◽  
The United States ◽  
Encephalitis Virus ◽  
Eastern Equine Encephalitis Virus ◽  
Vector Surveillance ◽  
Eastern Equine Encephalitis ◽  
Mosquito Abundance ◽  
Equine Encephalitis Virus ◽  
Culex Nigripalpus

Eastern equine encephalitis virus (EEEV) is a highly dangerous alphavirus vectored by multiple mosquito species in the United states. Vector surveillance and control is used to prevent the spread of EEEV, so highly efficient and attractive traps are needed to accurately assess mosquito abundance. Mosquitoes can be captured in various physiological states (host-seeking, gravid, resting, etc.), depending on what trap type is used. this study analyzed 6 trap types to determine which captured the most EEEV vectors in saint Johns county. the trap types analyzed were the biogents sentinel trap, centers for Disease control (cDc) Light trap, the sentinel Mosquito Arbovirus capture Kit, Mosquito Magnet X trap, cDc resting trap, and gravid traps. For the gravid traps, two different infusions were tested: hay infusion and cattail infusion. Aedes atlanticus Dyar and Knab was the most abundant EEEV vector captured in this study. Other EEEV vectors collected were Aedes vexans (Meigen), Culex erraticus (Dyar and Knab), and Culex nigripalpus theobald. bG traps caught the highest abundance of EEEV vectors (1520 ± 743) compared to all the other trap types analyzed. Despite capturing multiple EEEV vectors during the testing period at the chosen site, Culiseta melanura (coquillett) and Coquillettidia perturbans (Walker) were never captured.

scholarly journals 49. Clinical Characteristics of the 2019 Eastern Equine Encephalitis Virus Outbreak in Michigan

2020 ◽  
Vol 7 (Supplement_1) ◽  
pp. S154-S154
Author(s):  
Adam T Ladzinski ◽  
Matthew T Rumschlag ◽  
Aditya Mehta ◽  
Eric Edewaard ◽  
Pimpawan Boapimp ◽  
...  
Keyword(s):  
Clinical Symptoms ◽  
The United States ◽  
Encephalitis Virus ◽  
Eastern Equine Encephalitis Virus ◽  
Radiographic Images ◽  
Eastern Equine Encephalitis ◽  
Male Predominance ◽  
Equine Encephalitis Virus ◽  
Neuroinvasive Disease ◽  
Neurologic Sequelae

Abstract Background Eastern Equine Encephalitis Virus (EEEV) is a mosquito-borne alphavirus responsible for unpredictable outbreaks of severe neurologic disease in humans. While the vast majority of human EEEV infections are either asymptomatic or clinically nonspecific, a minority of patients develops neuroinvasive disease (EEE), which is a devastating illness with a mortality of at least 30%. No treatments are known to be effective. EEEV infection is relatively rare in the United States, with an annual average nationwide incidence of 7 cases between 2009 and 2018. However, 2019 was an exceptionally active year for human EEEV disease, yielding 38 nationwide confirmed cases, including 10 in Michigan, comprising the state’s largest outbreak to date. Methods EEE cases were identified by a regional network of physicians. Cases were defined by presentation with clinical symptoms of encephalitis, and by identification of EEEV IgM antibodies or RNA in cerebrospinal fluid (CSF), or EEEV-specific IgM in serum as confirmed by plaque reduction neutralization test. Radiographic images were evaluated and clinical data abstracted through chart review and clinical follow-up where possible. Results Records from 7 patients were identified and reviewed. The median age was 64, with a male predominance, and all presented in August. Notably, commercial arboviral CSF serology was uniformly negative on the initial CSF sample, and diagnosis was not made until a mean of 23 days (range: 12–38 days) after presentation. Testing in public health laboratories yielded the diagnosis in 5 out of 7 cases. Imaging findings were heterogeneous, but most patients exhibited abnormal findings in the thalamus and/or basal ganglia, and one patient displayed prominent pons and midbrain abnormalities. 4 patients died, while 2 patients survived with severe neurologic sequelae, and 1 patient recovered without sequelae. One patient underwent a limited postmortem examination, which revealed diffuse meningoencephalitis and focal vascular necrosis. Conclusion EEE is a frequently fatal condition whose diagnosis is often delayed, and for which no effective treatments are known. Improved diagnostics are needed to facilitate further clinical studies of EEE and encourage the development of potential therapies. Disclosures All Authors: No reported disclosures

scholarly journals Ecology and Epidemiology of Eastern Equine Encephalitis Virus in the Northeastern United States: An Historical Perspective

2021 ◽  
Author(s):  
Philip M Armstrong ◽  
Theodore G Andreadis
Keyword(s):  
United States ◽  
Mosquito Species ◽  
Virus Transmission ◽  
Bird Species ◽  
Disease Outbreaks ◽  
Encephalitis Virus ◽  
Eastern Equine Encephalitis Virus ◽  
Northeastern United States ◽  
Eastern Equine Encephalitis ◽  
Equine Encephalitis Virus

Abstract In the current review, we examine the regional history, ecology, and epidemiology of eastern equine encephalitis virus (EEEV) to investigate the major drivers of disease outbreaks in the northeastern United States. EEEV was first recognized as a public health threat during an outbreak in eastern Massachusetts in 1938, but historical evidence for equine epizootics date back to the 1800s. Since then, sporadic disease outbreaks have reoccurred in the Northeast with increasing frequency and northward expansion of human cases during the last 20 yr. Culiseta melanura (Coquillett) (Diptera: Culicidae) serves as the main enzootic vector that drives EEEV transmission among wild birds, but this mosquito species will occasionally feed on mammals. Several species have been implicated as bridge vectors to horses and humans, with Coquilletstidia perturbans (Walker) as a leading suspect based on its opportunistic feeding behavior, vector competence, and high infection rates during recent disease outbreaks. A diversity of bird species are reservoir competent, exposed to EEEV, and serve as hosts for Cs. melanura, with a few species, including the wood thrush (Hlocichia mustelina) and the American robin (Turdus migratorius), contributing disproportionately to virus transmission based on available evidence. The major factors responsible for the sustained resurgence of EEEV are considered and may be linked to regional landscape and climate changes that support higher mosquito densities and more intense virus transmission.

scholarly journals Large-Scale Complete-Genome Sequencing and Phylodynamic Analysis of Eastern Equine Encephalitis Virus Reveals Source-Sink Transmission Dynamics in the United States

2018 ◽  
Vol 92 (12) ◽  
Author(s):  
Yi Tan ◽  
Tommy Tsan-Yuk Lam ◽  
Lea A. Heberlein-Larson ◽  
Sandra C. Smole ◽  
Albert J. Auguste ◽  
...  
Keyword(s):  
United States ◽  
Genetic Diversity ◽  
Mortality Rate ◽  
The United States ◽  
Encephalitis Virus ◽  
Eastern Equine Encephalitis Virus ◽  
Genome Sequences ◽  
Eastern Equine Encephalitis ◽  
Equine Encephalitis Virus ◽  
Source Sink

ABSTRACTEastern equine encephalitis virus (EEEV) has a high case-fatality rate in horses and humans, and Florida has been hypothesized to be the source of EEEV epidemics for the northeastern United States. To test this hypothesis, we sequenced complete genomes of 433 EEEV strains collected within the United States from 1934 to 2014. Phylogenetic analysis suggested EEEV evolves relatively slowly and that transmission is enzootic in Florida, characterized by higher genetic diversity and long-term local persistence. In contrast, EEEV strains in New York and Massachusetts were characterized by lower genetic diversity, multiple introductions, and shorter local persistence. Our phylogeographic analysis supported a source-sink model in which Florida is the major source of EEEV compared to the other localities sampled. In sum, this study revealed the complex epidemiological dynamics of EEEV in different geographic regions in the United States and provided general insights into the evolution and transmission of other avian mosquito-borne viruses in this region.IMPORTANCEEastern equine encephalitis virus (EEEV) infections are severe in horses and humans on the east coast of the United States with a >90% mortality rate in horses, an ∼33% mortality rate in humans, and significant brain damage in most human survivors. However, little is known about the evolutionary characteristics of EEEV due to the lack of genome sequences. By generating large collection of publicly available complete genome sequences, this study comprehensively determined the evolution of the virus, described the epidemiological dynamics of EEEV in different states in the United States, and identified Florida as one of the major sources. These results may have important implications for the control and prevention of other mosquito-borne viruses in the Americas.

scholarly journals The Structural Biology of Eastern Equine Encephalitis Virus, an Emerging Viral Threat

2021 ◽  
Author(s):  
S. Saif Hasan ◽  
Debajit Dey ◽  
Suruchi Singh ◽  
Matthew Martin
Keyword(s):  
Structural Biology ◽  
The United States ◽  
Encephalitis Virus ◽  
Eastern Equine Encephalitis Virus ◽  
Host Proteins ◽  
Structural Investigations ◽  
Eastern Equine Encephalitis ◽  
Equine Encephalitis Virus ◽  
Fundamental Biology ◽  
Functional Analyses

Alphaviruses are arboviruses that cause arthritis and encephalitis in humans. Eastern Equine Encephalitis Virus (EEEV) is a mosquito transmitted alphavirus that is implicated in severe encephalitis in humans with high mortality. However, limited insights are available into its fundamental biology of EEEV and residue-level details of its interactions with host proteins. In recent years, outbreaks of EEEV have been reported mainly in the United States, raising concerns about public safety. This review article summarizes recent advances in the structural biology of EEEV based mainly on recent single particle cryogenic electron microscopy (cryoEM) structures. Together with functional analyses of EEEV and related alphaviruses, these structural investigations provide clues to how EEEV interacts with host proteins, which may open avenues for the development of therapeutics.

scholarly journals The Structural Biology of Eastern Equine Encephalitis Virus, an Emerging Viral Threat

Pathogens ◽  
2021 ◽  
Vol 10 (8) ◽  
pp. 973
Author(s):  
S. Saif Hasan ◽  
Debajit Dey ◽  
Suruchi Singh ◽  
Matthew Martin
Keyword(s):  
Structural Biology ◽  
The United States ◽  
Encephalitis Virus ◽  
Eastern Equine Encephalitis Virus ◽  
Host Proteins ◽  
Structural Investigations ◽  
Eastern Equine Encephalitis ◽  
Equine Encephalitis Virus ◽  
Fundamental Biology ◽  
Functional Analyses

Alphaviruses are arboviruses that cause arthritis and encephalitis in humans. Eastern Equine Encephalitis Virus (EEEV) is a mosquito-transmitted alphavirus that is implicated in severe encephalitis in humans with high mortality. However, limited insights are available into the fundamental biology of EEEV and residue-level details of its interactions with host proteins. In recent years, outbreaks of EEEV have been reported mainly in the United States, raising concerns about public safety. This review article summarizes recent advances in the structural biology of EEEV based mainly on single-particle cryogenic electron microscopy (cryoEM) structures. Together with functional analyses of EEEV and related alphaviruses, these structural investigations provide clues to how EEEV interacts with host proteins, which may open avenues for the development of therapeutics.

scholarly journals Ecology of Eastern Equine Encephalitis Virus in the Southeastern United States: Incriminating Vector and Host Species Responsible for Virus Amplification, Persistence, and Dispersal

2021 ◽  
Author(s):  
Nathan D Burkett-Cadena ◽  
Jonathan F Day ◽  
Thomas R Unnasch
Keyword(s):  
North America ◽  
Phylogenetic Analyses ◽  
Mosquito Species ◽  
Severe Disease ◽  
Bird Species ◽  
Encephalitis Virus ◽  
Eastern North America ◽  
Eastern Equine Encephalitis Virus ◽  
Eastern Equine Encephalitis ◽  
Equine Encephalitis Virus

Abstract Eastern equine encephalitis virus (EEEV; family Togaviridae, genus Alphavirus) is a mosquito-borne pathogen found in eastern North America that causes severe disease in humans and horses. The mosquito Culiseta melanura (Coquillett) (Diptera: Culicidae) is the primary enzootic vector of EEEV throughout eastern North America while several mosquito species belonging to diverse genera serve as bridge vectors. The ecology of EEEV differs between northern and southern foci, with respect to phenology of outbreaks, important vertebrate hosts, and bridge vector species. Active transmission is limited to roughly half of the year in northern foci (New York, New Hampshire, Massachusetts, Connecticut), while year-round transmission occurs in the southeastern region (particularly Florida). Multiple phylogenetic analyses indicate that EEEV strains circulating in northern foci are likely transported from southern foci by migrating birds. Bird species that overwinter or migrate through Florida, are bitten by Cs. melanura in late spring, and arrive at northern breeding grounds in May are the most likely candidates to disperse EEEV northward. Available data indicate that common yellowthroat and green heron satisfy these criteria and could serve as virus dispersers. Understanding the factors that drive the phenology of Cs. melanura reproduction in the south and the timing of avian migration from southern foci could provide insight into how confluence of these biological phenomena shapes outbreaks of EEE throughout its range. This information could be used to develop models predicting the likelihood of outbreaks in a given year, allowing vector control districts to more efficiently marshal resources necessary to protect their stakeholders.

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