scholarly journals Long-term surveillance defines spatial and temporal patterns implicating Culex tarsalis as the primary vector of West Nile virus in Iowa, USA

2018 ◽  
Author(s):  
Brendan M. Dunphy ◽  
Kristofer B. Kovach ◽  
Ella J. Gehrke ◽  
Eleanor N. Field ◽  
Wayne A. Rowley ◽  
...  
Keyword(s):  
West Nile Virus ◽  
Disease Transmission ◽  
Climatic Factors ◽  
Strong Support ◽  
The United States ◽  
Culex Tarsalis ◽  
Mosquito Vectors ◽  
Spatial And Temporal Patterns ◽  
West Nile

AbstractWest Nile virus (WNV) has become the most epidemiologically important mosquito-borne disease in the United States, causing ∼50,000 cases since its introduction in 1999. Transmitted primarily by Culex species, WNV transmission requires the complex interplay between bird reservoirs and mosquito vectors, with human cases the result of epizootic spillover. To better understand the intrinsic factors that drive these interactions, we have compiled infection data from sentinel chickens, mosquito vectors, and human cases in Iowa over a 15 year period (2002-2016) to better understand the spatial and temporal components that drive WNV transmission. Supplementing these findings with mosquito abundance, distribution, and host preferences data, we provide strong support that Culex tarsalis is the most important vector of human WNV infections in the region. Finally, we identify underlying climatic factors (temperature and drought) that are associated with inter-annual trends in WNV intensity. Together, our analysis provides new insights into WNV infection patterns in multiple hosts and highlights the importance of long-term surveillance to understand the dynamics of mosquito-borne-disease transmission.

scholarly journals Long-term surveillance defines spatial and temporal patterns implicating Culex tarsalis as the primary vector of West Nile virus

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Brendan M. Dunphy ◽  
Kristofer B. Kovach ◽  
Ella J. Gehrke ◽  
Eleanor N. Field ◽  
Wayne A. Rowley ◽  
...  
Keyword(s):  
West Nile Virus ◽  
Temporal Patterns ◽  
Culex Tarsalis ◽  
Spatial And Temporal Patterns ◽  
West Nile ◽  
Primary Vector

scholarly journals West Nile Virus Infection in the Central Nervous System

F1000Research ◽  
2016 ◽  
Vol 5 ◽  
pp. 105 ◽  
Author(s):  
Evandro R. Winkelmann ◽  
Huanle Luo ◽  
Tian Wang
Keyword(s):  
Central Nervous System ◽  
Nervous System ◽  
West Nile Virus ◽  
Animal Models ◽  
West Nile Virus Infection ◽  
The United States ◽  
West Nile ◽  
Neurological Sequelae ◽  
The Central Nervous System

West Nile virus (WNV), a neurotropic single-stranded flavivirus has been the leading cause of arboviral encephalitis worldwide.  Up to 50% of WNV convalescent patients in the United States were reported to have long-term neurological sequelae.  Neither antiviral drugs nor vaccines are available for humans.  Animal models have been used to investigate WNV pathogenesis and host immune response in humans.  In this review, we will discuss recent findings from studies in animal models of WNV infection, and provide new insights on WNV pathogenesis and WNV-induced host immunity in the central nervous system.

scholarly journals Spatiotemporal Analysis of West Nile Virus Epidemic in South Banat District, Serbia, 2017–2019

Animals ◽  
2021 ◽  
Vol 11 (10) ◽  
pp. 2951
Author(s):  
Sonja Radojicic ◽  
Aleksandar Zivulj ◽  
Tamas Petrovic ◽  
Jakov Nisavic ◽  
Vesna Milicevic ◽  
...  
Keyword(s):  
West Nile Virus ◽  
Negative Binomial ◽  
Climatic Factors ◽  
The United States ◽  
Wild Birds ◽  
Water Levels ◽  
Maximum Temperature ◽  
Negative Binomial Regression Model ◽  
West Nile Fever ◽  
West Nile

West Nile virus (WNV) is an arthropod-born pathogen, which is transmitted from wild birds through mosquitoes to humans and animals. At the end of the 20th century, the first West Nile fever (WNF) outbreaks among humans in urban environments in Eastern Europe and the United States were reported. The disease continued to spread to other parts of the continents. In Serbia, the largest number of WNV-infected people was recorded in 2018. This research used spatial statistics to identify clusters of WNV infection in humans and animals in South Banat County, Serbia. The occurrence of WNV infection and risk factors were analyzed using a negative binomial regression model. Our research indicated that climatic factors were the main determinant of WNV distribution and were predictors of endemicity. Precipitation and water levels of rivers had an important influence on mosquito abundance and affected the habitats of wild birds, which are important for maintaining the virus in nature. We found that the maximum temperature of the warmest part of the year and the annual temperature range; and hydrographic variables, e.g., the presence of rivers and water streams were the best environmental predictors of WNF outbreaks in South Banat County.

scholarly journals West Nile Virus: Measures against Emergence in Malaysia

2019 ◽  
Vol 4 (1) ◽  
pp. 1-6
Author(s):  
Yasmin AR
Keyword(s):  
Public Health ◽  
West Nile Virus ◽  
Natural Habitat ◽  
The United States ◽  
Global Public Health ◽  
Mosquito Vectors ◽  
West Nile ◽  
Public Health Threat ◽  
Successful Establishment ◽  
Animal Vaccination

West Nile virus has a potential to emerge in new areas and cause large epidemics as was witnessed in the United States following its introduction in 1999. The virus is now a global public health threat, having been detected on every continent except Antarc tica. Once restricted to Africa, its expansion beyond its natural habitat is related to some viral, vectoral, anthropologic and environmental factors. The successful establishment and spread of the virus depend in part on viral adaptations, availability of competent hosts and mosquito vectors and suitable environmental conditions. A combination of measures can be applied to minimise the likelihood of a WN virus epidemic. Available vaccines are only for veterinary use, human vaccines are still in development . Vector control, animal vaccination, targeted surveillance and strong cooperation between relevant authorities are important in preventing a WN virus epidemic in Malaysia.

scholarly journals Identification of microRNAs in the West Nile virus vector Culex tarsalis

2021 ◽  
Author(s):  
Sultan Asad ◽  
Ahmed M Mehdi ◽  
Sujit Pujhari ◽  
Claudia Rueckert ◽  
Gregory D Ebel ◽  
...  
Keyword(s):  
West Nile Virus ◽  
Cell Line ◽  
Rna Sequencing ◽  
Small Rna ◽  
The United States ◽  
Small Rna Sequencing ◽  
Culex Tarsalis ◽  
Sequencing Data ◽  
West Nile

Background: microRNAs (miRNAs) represent a group of small non-coding RNAs that are crucial gene regulators of important biological functions including development and pathogen defense in most living organisms. Presently, there is a lack of availability of information regarding the miRNAs in the mosquito Culex tarsalis, which is one of the most important vectors of West Nile virus (WNV) in the United States. We used small RNA sequencing data and in vitro and in vivo experiments to identify and validate the presence of a repertoire of miRNAs in Cx. tarsalis mosquitoes. Results: Using bioinformatic approaches we analyzed small RNA sequencing data from the Cx. tarsalis CT embryonic cell line to discover 86 miRNAs. Consistent with other mosquitoes such as Aedes albopictus and Cx. quinquefasciatus, mi-184 was found to be the most abundant miRNA in Cx tarsalis. We also identified an additional 20 novel miRNAs from the recently sequenced Cx. tarsalis genome, for a total of 106 miRNAs identified in this study. The presence of selected miRNAs was biologically validated in both cell line and adult Cx. tarsalis mosquitoes using RT-qPCR and sequencing. Conclusions: Cx. tarsalis is an important vector of many medically important pathogens including WNV and Western Equine encephalitis. Here we report a detailed insight into the miRNA population in Cx. tarsalis mosquitoes. These results will open new avenues of research deciphering the role of miRNAs in different Cx. tarsalis biological events such as development, metabolism, immunity and pathogen infection.

scholarly journals Clinical Spectrum of West Nile Virus Neuroinvasive Disease

2019 ◽  
Vol 10 (1) ◽  
pp. 43-47 ◽  
Author(s):  
Andrew Yu ◽  
Emily Ferenczi ◽  
Kareem Moussa ◽  
Dean Eliott ◽  
Marcelo Matiello
Keyword(s):  
Risk Factors ◽  
West Nile Virus ◽  
Febrile Illness ◽  
The United States ◽  
Ocular Involvement ◽  
West Nile ◽  
Presenting Symptoms ◽  
Neuroinvasive Disease ◽  
Neurologic Sequelae

West Nile virus (WNV) is the most common arbovirus infection in the United States. The diagnosis requires consideration of not only a broad spectrum of presenting symptoms, ranging from a mild febrile illness to severe encephalitis and acute flaccid paralysis, but also public health risk factors and seasonality. There is no approved targeted therapy for WNV, so treatment relies on supportive care, management of neurologic sequelae and airway, treatment of other systems including the eye, and aggressive rehabilitation. Here, we describe a series of 3 cases of WNV encountered in September 2018 at one institution. First, we describe a case of WNV encephalitis with worsened dyskinesias and a relatively good recovery. Second, we describe a severe WNV encephalitis with overlying motor neuron involvement with a poor outcome. Finally, we describe a case of a WNV meningitis with significant bilateral chorioretinitis, an underappreciated complication of WNV infections. Through these cases, we review the epidemiology of WNV, risk factors for infection, the neurologic sequalae and long-term outcomes, and the importance of recognizing ocular involvement to prevent ophthalmologic complications.

scholarly journals Parameters of Mosquito-Enhanced West Nile Virus Infection

2015 ◽  
Vol 90 (1) ◽  
pp. 292-299 ◽  
Author(s):  
Lindsey A. Moser ◽  
Pei-Yin Lim ◽  
Linda M. Styer ◽  
Laura D. Kramer ◽  
Kristen A. Bernard
Keyword(s):  
United States ◽  
West Nile Virus ◽  
The United States ◽  
Culex Tarsalis ◽  
West Nile ◽  
Virus Inoculation ◽  
Content Type ◽  
Mosquito Saliva ◽  
Vertebrate Hosts ◽  
Robust System

ABSTRACT The arthropod-borne West Nile virus (WNV) emerged in New York State in 1999 and quickly spread throughout the United States. Transmission is maintained in an enzootic cycle in which infected mosquitoes transmit the virus to susceptible hosts during probing and feeding. Arthropod-derived components within the viral inoculum are increasingly acknowledged to play a role in infection of vertebrate hosts. We previously showed that Culex tarsalis mosquito saliva and salivary gland extract (SGE) enhance the in vivo replication of WNV. Here, we characterized the effective dose, timing, and proximity of saliva and SGE administration necessary for enhancement of WNV viremia using a mouse model. Mosquito saliva and SGE enhanced viremia in a dose-dependent manner, and a single mosquito bite or as little as 0.01 μg of SGE was effective at enhancing viremia, suggesting a potent active salivary factor. Viremia was enhanced when SGE was injected in the same location as virus inoculation from 24 h before virus inoculation through 12 h after virus inoculation. These results were confirmed with mosquito saliva deposited by uninfected mosquitoes. When salivary treatment and virus inoculation were spatially separated, viremia was not enhanced. In summary, the effects of mosquito saliva and SGE were potent, long lasting, and localized, and these studies have implications for virus transmission in nature, where vertebrate hosts are fed upon by both infected and uninfected mosquitoes over time. Furthermore, our model provides a robust system to identify the salivary factor(s) responsible for enhancement of WNV replication. IMPORTANCE Mosquito-borne viruses are a significant class of agents causing emerging infectious diseases. WNV has caused over 18,000 cases of neuroinvasive disease in the United States since its emergence. We have shown that Culex tarsalis mosquito saliva and SGE enhance the replication of WNV. We now demonstrate that saliva and SGE have potent, long-lasting, and localized effects. Our model provides a robust system to identify the salivary factor(s) and characterize the mechanism responsible for enhancement of WNV replication. These studies could lead to the identification of novel prophylactic or treatment options useful in limiting the spread of WNV, other mosquito-borne viruses, and the diseases that they cause.

Models and Surveillance Systems to Detect and Predict West Nile Virus Outbreaks

2019 ◽  
Vol 56 (6) ◽  
pp. 1508-1515 ◽  
Author(s):  
Christopher M Barker
Keyword(s):  
West Nile Virus ◽  
Disease Risk ◽  
The United States ◽  
Surveillance Systems ◽  
Data Systems ◽  
Spatial And Temporal Patterns ◽  
West Nile ◽  
Data Services ◽  
Surveillance Programs ◽  
Electronic Data Systems

Abstract Over the past 20 yr, many models have been developed to predict risk for West Nile virus (WNV; Flaviviridae: Flavivirus) disease in the human population. These models have aided our understanding of the meteorological and land-use variables that drive spatial and temporal patterns of human disease risk. During the same period, electronic data systems have been adopted by surveillance programs across much of the United States, including a growing interest in integrated data services that preserve the autonomy and attribution of credit to originating agencies but facilitate data sharing, analysis, and visualization at local, state, and national scales. At present, nearly all predictive models have been limited to the scientific literature, with few having been implemented for use by public-health and vector-control decision makers. The current article considers the development of models for spatial patterns, early warning, and early detection of WNV over the last 20 yr and considers some possible paths toward increasing the utility of these models for guiding interventions.

Polymorphic microsatellite loci from the West Nile virus vector Culex tarsalis

2006 ◽  
Vol 6 (3) ◽  
pp. 680-682 ◽  
Author(s):  
JASON L. RASGON ◽  
MEERA VENKATESAN ◽  
CATHERINE J. WESTBROOK ◽  
MARY CLAIRE HAUER
Keyword(s):  
West Nile Virus ◽  
Microsatellite Loci ◽  
Virus Vector ◽  
Culex Tarsalis ◽  
The West ◽  
West Nile ◽  
Polymorphic Microsatellite
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