scholarly journals Surveillance of West Nile virus infection in Kashgar Region, Xinjiang, China, 2013–2016

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Yanping Zhang ◽  
Wenwen Lei ◽  
Yali Wang ◽  
Haitian Sui ◽  
Bo Liu ◽  
...  
Keyword(s):  
West Nile Virus ◽  
Neutralizing Antibodies ◽  
Culex Pipiens ◽  
Mosquito Species ◽  
Mainland China ◽  
West Nile Virus Infection ◽  
Viral Meningitis ◽  
Immunoglobulin M ◽  
West Nile ◽  
Epidemiological Characteristics

AbstractWest Nile virus (WNV) was first isolated in mainland China from mosquitoes in Jiashi County, Kashgar Region, Xinjiang in 2011, following local outbreaks of viral meningitis and encephalitis caused by WNV. To elaborate the epidemiological characteristics of the WNV, surveillance of WNV infection in Kashgar Region, Xinjiang from 2013 to 2016 were carried out. Blood and CSF samples from surveillance human cases, blood of domestic chicken, cattle, sheep and mosquitoes in Kashgar Region were collected and detected. There were human 65 WNV Immunoglobulin M (IgM) antibody positive cases by ELISA screening, 6 confirmed WNV cases by the plaque reduction neutralization test (PRNT) screening. These cases occurred mainly concentrated in August to September of each year, and most of them were males. WNV-neutralizing antibodies were detected in both chickens and sheep, and the positive rates of neutralizing antibodies were 15.5% and 1.78%, respectively. A total of 15,637 mosquitoes were collected in 2013–2016, with Culex pipiens as the dominant mosquito species. Four and 1 WNV-positive mosquito pools were detected by RT-qPCR in 2013 and 2016 respectively. From these data, we can confirm that Jiashi County may be a natural epidemic foci of WNV disease, the trend highlights the routine virology surveillance in WNV surveillance cases, mosquitoes and avian should be maintained and enhanced to provide to prediction and early warning of outbreak an epidemic of WNV in China.

scholarly journals Pre-existing Microfilarial Infections of American Robins (Passeriformes: Turdidae) and Common Grackles (Passeriformes: Icteridae) Have Limited Impact on Enhancing Dissemination of West Nile Virus in Culex pipiens Mosquitoes (Diptera: Culicidae)

2020 ◽  
Author(s):  
Jefferson A Vaughan ◽  
Juanita Hinson ◽  
Elizabeth S Andrews ◽  
Michael J Turell
Keyword(s):  
West Nile Virus ◽  
Viral Infection ◽  
Culex Pipiens ◽  
Mosquito Species ◽  
Immature Stages ◽  
West Nile ◽  
Limited Impact ◽  
Nematode Parasites ◽  
American Robins ◽  
Specific Virus

Abstract Microfilariae (MF) are the immature stages of filarial nematode parasites and inhabit the blood and dermis of all classes of vertebrates, except fish. Concurrent ingestion of MF and arboviruses by mosquitoes can enhance mosquito transmission of virus compared to when virus is ingested alone. Shortly after being ingested, MF penetrate the mosquito’s midgut and may introduce virus into the mosquito’s hemocoel, creating a disseminated viral infection much sooner than normal. This phenomenon is known as microfilarial enhancement. Both American Robins and Common Grackles harbor MF—that is, Eufilaria sp. and Chandlerella quiscali von Linstow (Spirurida: Onchocercidae), respectively. We compared infection and dissemination rates in Culex pipiens L. mosquitoes that fed on birds with and without MF infections that had been infected with West Nile virus (WNV). At moderate viremias, about 107 plaque-forming units (pfu)/ml of blood, there were no differences in infection or dissemination rates among mosquitoes that ingested viremic blood from a bird with or without microfilaremia. At high viremias, >108.5 pfu/ml, mosquitoes feeding on a microfilaremic Grackle with concurrent viremia had significantly higher infection and dissemination rates than mosquitoes fed on viremic Grackles without microfilaremia. Microfilarial enhancement depends on the specific virus, MF, and mosquito species examined. How virus is introduced into the hemocoel by MF differs between the avian/WNV systems described here (i.e., leakage) and various arboviruses with MF of the human filarid, Brugia malayi (Brug) (Spirurida: Onchocercidae) (i.e., cotransport). Additional studies are needed to determine if other avian species and their MF are involved in the microfilarial enhancement of WNV in nature.

scholarly journals Serological evidence of West Nile Virus infection among humans in the southern Provinces of Morocco

2013 ◽  
Vol 7 (12) ◽  
pp. 999-1002 ◽  
Author(s):  
Hicham El Rhaffouli ◽  
Idriss Lahlou-Amine ◽  
Chafiqua Loutfi ◽  
Abdellilah Laraqui ◽  
Tahar Bajjou ◽  
...  
Keyword(s):  
West Nile Virus ◽  
Virus Infection ◽  
Neutralizing Antibodies ◽  
West Nile Virus Infection ◽  
Serological Evidence ◽  
West Nile ◽  
Specific Antibodies

Introduction: The objective of this study was to determine the prevalence of West Nile Virus infection in the southern provinces of Morocco. Methodology: A total of 250 sera, collected during 2012 in the province of Dakhla, were analyzed by microneutralisation assay. Results: WNV-neutralizing antibodies were detected in 13 samples (5.2%). The participants with WNV-specific antibodies were significantly younger than the rest of the population (p = 0.009). The positivity rate was higher among women (6.3%) than men (3.6%) (p = 0.26). Conclusions: This is the first serological evidence of WNV infection among humans in the southern provinces of Morocco.

scholarly journals Induction of Epitope-Specific Neutralizing Antibodies against West Nile Virus

2007 ◽  
Vol 81 (21) ◽  
pp. 11828-11839 ◽  
Author(s):  
Theodore Oliphant ◽  
Grant E. Nybakken ◽  
S. Kyle Austin ◽  
Qing Xu ◽  
Jonathan Bramson ◽  
...  
Keyword(s):  
West Nile Virus ◽  
Human Serum ◽  
Neutralizing Antibodies ◽  
Immunoglobulin M ◽  
Late Time ◽  
Loss Of Function ◽  
Serum Samples ◽  
West Nile ◽  
E Protein ◽  
Low Levels

ABSTRACT Previous studies have established that an epitope on the lateral ridge of domain III (DIII-lr) of West Nile virus (WNV) envelope (E) protein is recognized by strongly neutralizing type-specific antibodies. In contrast, an epitope against the fusion loop in domain II (DII-fl) is recognized by flavivirus cross-reactive antibodies with less neutralizing potential. Using gain- and loss-of-function E proteins and wild-type and variant WNV reporter virus particles, we evaluated the expression pattern and activity of antibodies against the DIII-lr and DII-fl epitopes in mouse and human serum after WNV infection. In mice, immunoglobulin M (IgM) antibodies to the DIII-lr epitope were detected at low levels at day 6 after infection. However, compared to IgG responses against other epitopes in DI and DII, which were readily detected at day 8, the development of IgG against DIII-lr epitope was delayed and did not appear consistently until day 15. This late time point is notable since almost all death after WNV infection in mice occurs by day 12. Nonetheless, at later time points, DIII-lr antibodies accumulated and comprised a significant fraction of the DIII-specific IgG response. In sera from infected humans, DIII-lr antibodies were detected at low levels and did not correlate with clinical outcome. In contrast, antibodies to the DII-fl were detected in all human serum samples and encompassed a significant percentage of the anti-E protein response. Our experiments suggest that the highly neutralizing DIII-lr IgG antibodies have little significant role in primary infection and that the antibody response of humans may be skewed toward the induction of cross-reactive, less-neutralizing antibodies.

Frequency of Zika Virus Immunoglobulin M Antibody in Persons with West Nile Virus Infection

2021 ◽  
Author(s):  
Susan L. Hills ◽  
Janeen Laven ◽  
Brad J. Biggerstaff ◽  
Olga Kosoy ◽  
J. Erin Staples ◽  
...  
Keyword(s):  
West Nile Virus ◽  
Virus Infection ◽  
Zika Virus ◽  
West Nile Virus Infection ◽  
Immunoglobulin M ◽  
West Nile
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