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 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 Predicting the spatio-temporal spread of West Nile virus in Europe

2021 ◽  
Vol 15 (1) ◽  
pp. e0009022
Author(s):  
José-María García-Carrasco ◽  
Antonio-Román Muñoz ◽  
Jesús Olivero ◽  
Marina Segura ◽  
Raimundo Real
Keyword(s):  
West Nile Virus ◽  
Large Scale ◽  
River Basins ◽  
Maximum Temperature ◽  
Environmental Predictors ◽  
Migration Routes ◽  
West Nile Fever ◽  
Environmental Model ◽  
West Nile ◽  
First Case

West Nile virus is a widely spread arthropod-born virus, which has mosquitoes as vectors and birds as reservoirs. Humans, as dead-end hosts of the virus, may suffer West Nile Fever (WNF), which sometimes leads to death. In Europe, the first large-scale epidemic of WNF occurred in 1996 in Romania. Since then, human cases have increased in the continent, where the highest number of cases occurred in 2018. Using the location of WNF cases in 2017 and favorability models, we developed two risk models, one environmental and the other spatio-environmental, and tested their capacity to predict in 2018: 1) the location of WNF; 2) the intensity of the outbreaks (i.e. the number of confirmed human cases); and 3) the imminence of the cases (i.e. the Julian week in which the first case occurred). We found that climatic variables (the maximum temperature of the warmest month and the annual temperature range), human-related variables (rain-fed agriculture, the density of poultry and horses), and topo-hydrographic variables (the presence of rivers and altitude) were the best environmental predictors of WNF outbreaks in Europe. The spatio-environmental model was the most useful in predicting the location of WNF outbreaks, which suggests that a spatial structure, probably related to bird migration routes, has a role in the geographical pattern of WNF in Europe. Both the intensity of cases and their imminence were best predicted using the environmental model, suggesting that these features of the disease are linked to the environmental characteristics of the areas. We highlight the relevance of river basins in the propagation dynamics of the disease, as outbreaks started in the lower parts of the river basins, from where WNF spread towards the upper parts. Therefore, river basins should be considered as operational geographic units for the public health management of the disease.

scholarly journals Up-to-date knowledge of West Nile virus infection

2009 ◽  
Vol 62 (5-6) ◽  
pp. 231-235
Author(s):  
Ivana Hrnjakovic-Cvjetkovic ◽  
Dejan Cvjetkovic ◽  
Dusan Petric ◽  
Vesna Milosevic ◽  
Vera Jerant-Patic ◽  
...  
Keyword(s):  
West Nile Virus ◽  
Virus Infection ◽  
Mosquito Control ◽  
Virus Disease ◽  
West Nile Virus Infection ◽  
The United States ◽  
Flaccid Paralysis ◽  
Adult Mosquito ◽  
West Nile Fever ◽  
West Nile

Virus West Nile virus is a single-stranded RNA virus of the family Flaviviridae, genus Flavivirus. Epidemiology West Nile virus is maintained in the cycle involving culicine mosquitoes and birds .Humans typically acquire West Nile infection through a bite from infected adult mosquito. Person to person transmission can occur through organ transplantation, blood and blood product transfusions, transplacentally and via brest milk. Human cases of West Nile infections were recorded in Africa, Israel, Russia, India, Pakistan. In Romania in 1996 West Nile fever occurred with hundreds of neurologic cases and 17 fatalities. First human cases in the United States were in New York City where 59 persons were infected and had fever, meningitis, encephalitis and flaccid paralysis. Clinical manifestation Most human cases are asymptomatic. The majority of symptomatic patients have a self limited febrile illness. Fatigue, nausea, vomiting, eye pain, headache, myalgias, artralgias, lymphadenopathy and rash are common complaints. Less than 1% of all infected persons develop more severe neurologic illness including meningitis, encefalitis and flaccid paralysis. Laboratory diagnosis Diagnosis of West Nile virus infection is based on serologic testing, isolation of virus from patient samples and detection of viral antigen or viral genom. ELISA test and indirect immunofluorescenceassay are used for detecting IgM and IgG antibodies in serum and cerebrospinal fluid. Treatment In vitro studies have suggested that ribavirin and interferon alfa -2b may be useful in the treatment of West Nile virus disease. Prevention The most important measures are mosquito control program and personal protective measures. .

scholarly journals Probabilistic Evaluation of Null Models for West Nile Virus in the United States

2021 ◽  
Author(s):  
Alexander C Keyel ◽  
A. Marm Marmaduke Kilpatrick
Keyword(s):  
United States ◽  
West Nile Virus ◽  
Negative Binomial ◽  
Temporal Dynamics ◽  
The United States ◽  
Null Models ◽  
West Nile ◽  
Spatial And Temporal Scales ◽  
New Models ◽  
Future Direction

Null models provide a useful baseline for the development of new models. A variety of options for null models exist. These options have become more sophisticated with the advent of probabilistic modeling approaches. Here, we evaluate 10 different null models for West Nile virus, a primarily mosquito-borne disease introduced to the United States in 1999. The Historical Null was significantly better than all models other than the Negative Binomial. We recommend the use of either of these models as a baseline when developing new models to predict spatial and temporal dynamics of West Nile virus at the county-annual scale. We expect these results to be scale-dependent, and a future direction is to examine performance of null models at finer spatial and temporal scales.

scholarly journals Evidence of West Nile Virus (WNV) Circulation in Wild Birds and WNV RNA Negativity in Mosquitoes of the Danube Delta Biosphere Reserve, Romania, 2016

2019 ◽  
Vol 4 (3) ◽  
pp. 116 ◽  
Author(s):  
Ana Vasić ◽  
Luanda Oșlobanu ◽  
Mihai Marinov ◽  
Luciana Crivei ◽  
Ioana Rățoi ◽  
...  
Keyword(s):  
West Nile Virus ◽  
Biosphere Reserve ◽  
Wild Birds ◽  
Danube Delta ◽  
West Nile Fever ◽  
Mammal Species ◽  
West Nile ◽  
Transmission Cycle ◽  
Reverse Transcription Quantitative Pcr ◽  
Danube Delta Biosphere Reserve

West Nile virus (WNV) is a zoonotic flavivirus whose transmission cycle in nature includes wild birds as amplifying hosts and ornithophilic mosquito vectors. Bridge vectors can transmit WNV to mammal species potentially causing West Nile Fever. Wild bird migration is a mode of WNV introduction into new areas. The Danube Delta Biosphere Reserve (DDBR) is a major stopover of wild birds migrating between Europe and Africa. The aim of this study was to investigate the presence of WNV in the DDBR during the 2016 transmission season in wild birds and mosquitoes. Blood from 68 wild birds (nine different species) trapped at four different locations was analyzed by competitive ELISA and Virus Neutralization Test (VNT), revealing positive results in 8/68 (11.8%) of the wild birds by ELISA of which six samples (three from juvenile birds) were confirmed seropositive by VNT. Mosquitoes (n = 6523, 5 genera) were trapped with CDC Mini Light traps at two locations and in one location resting mosquitoes were caught. The presence of WNV RNA was tested in 134 pools by reverse transcription quantitative PCR (RT-qPCR). None of the pools was positive for WNV-specific RNA. Based on the obtained results, WNV was circulating in the DDBR during 2016.

scholarly journals 338. Analysis of Etiologies of Aseptic Meningitis within a Nation-Wide Hospital Network

2020 ◽  
Vol 7 (Supplement_1) ◽  
pp. S239-S239
Author(s):  
Arunmozhi S Aravagiri ◽  
Scott Kubomoto ◽  
Ayutyanont Napatkamon ◽  
Sarah Wilson ◽  
Sudhakar Mallela
Keyword(s):  
United States ◽  
West Nile Virus ◽  
Aseptic Meningitis ◽  
Epidemiologic Study ◽  
The United States ◽  
Positive Test ◽  
Diagnostic Tools ◽  
West Nile ◽  
Varicella Zoster ◽  
The Us

Abstract Background Aseptic meningitis can be caused by an array of microorganisms, both bacterial and non-bacterial, as well as non-infectious conditions. Some etiologies of aseptic meningitis require treatment with antibiotics, antiviral, antifungals, anti-parasitic agents, immunosuppressants, and or chemotherapy. There are limited diagnostic tools for diagnosing certain types of aseptic meningitis, therefore knowing the differential causes of aseptic meningitis, and their relative percentages may assist in diagnosis. Review of the literature reveals that there are no recent studies of etiologies of aseptic meningitis in the United States (US). This is an epidemiologic study to delineate etiologies of aseptic meningitis in a large database of 185 HCA hospitals across the US. Methods Data was collected from January 2016 to December 2019 on all patients diagnosed with meningitis. CSF PCR studies, and CSF antibody tests were then selected for inclusion. Results Total number of encounters were 3,149 hospitalizations. Total number of individual labs analyzed was 10,613, and of these 262 etiologies were identified. 23.6% (62) of cases were due to enterovirus, 18.7% (49) due to HSV-2, 14.5% (38) due to West Nile virus, 13.7% (36) due to Varicella zoster (VZV), 10.5% (27) due to Cryptococcus. Additionally, we analyzed the rate of positive test results by region. Nationally, 9.7% of tests ordered for enterovirus were positive. In contrast, 0.5% of tests ordered for HSV 1 were positive. The southeastern United States had the highest rate of positive tests for HSV 2 (7% of tests ordered for HSV 2 were positive). The central United States had the highest rate of positive test for West Nile virus (11% of tests ordered for West Nile were positive). The northeastern region and the highest rate of positive tests for varicella zoster (18%). Table 1: Percentage of positive CSF tests (positive tests/tests ordered) Table 2: Lists the number of HIV patients and transplant patients that had positive CSF PCR/serologies Figure 1: Percentage of positive CSF tests in each region Conclusion Approximately 40% of aseptic meningitis population had treatable etiologies. A third of the Cryptococcus meningitis population had HIV. Furthermore, enteroviruses had the majority of cases within the US, which are similar to studies done in other parts of the world. Disclosures All Authors: No reported disclosures

scholarly journals Meteorological Conditions Associated with Increased Incidence of West Nile Virus Disease in the United States, 2004–2012

2015 ◽  
Vol 92 (5) ◽  
pp. 1013-1022 ◽  
Author(s):  
Micah B. Hahn ◽  
Roger S. Nasci ◽  
Mark J. Delorey ◽  
Rebecca J. Eisen ◽  
Andrew J. Monaghan ◽  
...  
Keyword(s):  
United States ◽  
West Nile Virus ◽  
Virus Disease ◽  
The United States ◽  
Meteorological Conditions ◽  
West Nile

A Snapshot Avian Surveillance Reveals West Nile Virus and Evidence of Wild Birds Participating in Toscana Virus Circulation

2017 ◽  
Vol 17 (10) ◽  
pp. 698-708 ◽  
Author(s):  
Sabri Hacioglu ◽  
Ender Dincer ◽  
Cafer Tayer Isler ◽  
Zeynep Karapinar ◽  
Veysel Soydal Ataseven ◽  
...  
Keyword(s):  
West Nile Virus ◽  
Wild Birds ◽  
Toscana Virus ◽  
West Nile

The survey of wild birds for West Nile virus in Poland

2011 ◽  
Vol 14 (4) ◽  
pp. 573-577 ◽  
Author(s):  
J. Niczyporuk ◽  
E. Samorek-Salamonowicz ◽  
W. Kozdruń ◽  
Z. Mizak
Keyword(s):  
West Nile Virus ◽  
Genetic Material ◽  
Early Spring ◽  
Wild Birds ◽  
Rt Pcr ◽  
West Nile ◽  
Late Autumn ◽  
The Brain

The survey of wild birds for West Nile virus in PolandTwo thousand one hundred and forty birds belonging to 39 different species from different locations in Poland were examined. The study has taken place from the early spring till late autumn 2007-2010 when the activity of the mosquitoes was the highest. The brain samples were taken from the birds and whole cellular RNA was isolated, then the RT-PCR and NRT-PCR were performed to detect the presence of West Nile virus (WNV). The obtained results were confirmed by the commercial WNV Kit. No genetic material of WNV was found in the examined samples.

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