scholarly journals West Nile Virus Seroprevalence in the Italian Tuscany Region from 2016 to 2019

Pathogens ◽  
2021 ◽  
Vol 10 (7) ◽  
pp. 844
Author(s):  
Serena Marchi ◽  
Emanuele Montomoli ◽  
Simonetta Viviani ◽  
Simone Giannecchini ◽  
Maria A. Stincarelli ◽  
...  

Although in humans West Nile virus is mainly the cause of mild or sub-clinical infections, in some cases a neuroinvasive disease may occur predominantly in the elderly. In Italy, several cases of West Nile virus infection are reported every year. Tuscany was the first Italian region where the virus was identified; however, to date only two cases of infection have been reported in humans. This study aimed at evaluating the prevalence of antibodies against West Nile virus in the area of Siena Province to estimate the recent circulation of the virus. Human serum samples collected in Siena between 2016 and 2019 were tested for the presence of antibodies against West Nile virus by ELISA. ELISA positive samples were further evaluated using immunofluorescence, micro neutralization, and plaque reduction neutralization assays. In total, 1.9% (95% CI 1.2–3.1) and 1.4% (95% CI 0.8–2.4) of samples collected in 2016–2017 were positive by ELISA and immunofluorescence assay, respectively. Neutralizing antibodies were found in 0.7% (95% CI 0.3–1.5) of samples. Additionally, 0.9% (95% CI 0.4–1.7) and 0.65% (95% CI 0.3–1.45) of samples collected in 2018–2019 were positive by ELISA and immunofluorescence assay, respectively. The prevalence of neutralizing antibodies was 0.5% (95% CI 0.2–1.3). Although no human cases of West Nile infection were reported in the area between 2016 and 2019 and virus prevalence in the area of Siena Province was as low as less than 1%, the active asymptomatic circulation confirms the potential concern of this emergent virus for human health.

Viruses ◽  
2020 ◽  
Vol 12 (10) ◽  
pp. 1099
Author(s):  
Gili Schvartz ◽  
Sharon Tirosh-Levy ◽  
Oran Erster ◽  
Roni Shenhar ◽  
Hadas Levy ◽  
...  

West Nile virus (WNV) and Usutu virus (USUV) are arboviruses transmitted by mosquito vectors. Whereas WNV is endemic in Israel, the Middle East, Europe, and in the Americas, data regarding the prevalence of USUV in the Middle East is limited. While both viruses share similar reservoirs and vectors, exposure of horses in the area to USUV have never been assessed. The aim of this study was to estimate the seroprevalence and co-exposure of WNV and USUV in horses in Israel. A total of 327 serum samples from healthy unvaccinated horses in Israel collected in 2018 were tested for neutralizing antibodies against WNV and USUV. Seroprevalence for neutralizing antibodies against WNV and USUV was 84.1% and 10.8%, respectively. Management and age were significantly associated with WNV and USUV seropositivity. This is the first report describing exposure of horses in Israel to USUV, which indicates that this zoonotic pathogen should be included in the differential diagnosis list of neuroinvasive disease in this country.


2016 ◽  
Vol 47 (1) ◽  
pp. 30-34
Author(s):  
Fatma Aybala Altay ◽  
Hayat Güven ◽  
Gönül Çiçek Şentürk ◽  
Sevgi Ferik ◽  
İrfan Şencan ◽  
...  

Background Myasthenia Gravis (MG) is an autoimmune disease which is characterised by disruption of signal transmission at neuromuscular junction. We aimed to search about a newly reported association between MG and West Nile Virus (WNV) infection. Methods We searched WNV IgG by ELISA in serum samples of 50 available MG patients and 38 controls. Results None of the samples gave positive results for past WNV infection. Conclusion No evidence of past WNV infection was found in our study population of MG patients. This may have been because MG has been showed to be related with neuroinvasive WNV, which none of our study subjects seem to have had based on their stories. New multicentre studies focusing on immunological mechanisms and held with larger groups or especially neuroinvasive disease patients can cast light onto the answer of this question.


2011 ◽  
Vol 16 (33) ◽  
Author(s):  
L Barzon ◽  
M Pacenti ◽  
R Cusinato ◽  
M Cattai ◽  
E Franchin ◽  
...  

In 2010, for the third consecutive year, human cases of West Nile virus (WNV) infection, including three confirmed cases of neuroinvasive disease and three confirmed cases of West Nile fever, were identified in north-eastern Italy. While in 2008 and 2009 all human cases of WNV disease were recorded in the south of the Veneto region, cases of WNV disease in 2010 additionally occurred in two relatively small northern areas of Veneto, located outside those with WNV circulation in the previous years. WNV IgG antibody prevalence in blood donors resident in Veneto was estimated as ranging from 3.2 per 1,000 in areas not affected by cases of WNV disease to 33.3 per 1,000 in a highly affected area of the Rovigo province. No further autochthonous human cases of WNV disease were notified in Italy in 2010. The recurrence of human cases of WNV infection for the third consecutive year strongly suggests WNV has become endemic in north-eastern Italy.


2012 ◽  
Vol 141 (3) ◽  
pp. 591-595 ◽  
Author(s):  
L. R. PETERSEN ◽  
P. J. CARSON ◽  
B. J. BIGGERSTAFF ◽  
B. CUSTER ◽  
S. M. BORCHARDT ◽  
...  

SUMMARYWest Nile virus (WNV) was first recognized in the USA in 1999. We estimated the cumulative incidence of WNV infection in the USA from 1999 to 2010 using recently derived age- and sex-stratified ratios of infections to WNV neuroinvasive disease (WNND) and the number of WNND cases reported to national surveillance. We estimate that over 3 million persons have been infected with WNV in the USA, with the highest incidence rates in the central plains states. These 3 million infections would have resulted in about 780 000 illnesses. A substantial number of WNV infections and illnesses have occurred during the virus' first decade in the USA.


2013 ◽  
Vol 7 (12) ◽  
pp. 999-1002 ◽  
Author(s):  
Hicham El Rhaffouli ◽  
Idriss Lahlou-Amine ◽  
Chafiqua Loutfi ◽  
Abdellilah Laraqui ◽  
Tahar Bajjou ◽  
...  

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.


2007 ◽  
Vol 81 (21) ◽  
pp. 11828-11839 ◽  
Author(s):  
Theodore Oliphant ◽  
Grant E. Nybakken ◽  
S. Kyle Austin ◽  
Qing Xu ◽  
Jonathan Bramson ◽  
...  

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.


2014 ◽  
Vol 8 (07) ◽  
pp. 914-918 ◽  
Author(s):  
Strahinja Medić ◽  
Rene Van den Hoven ◽  
Tamaš Petrović ◽  
Diana Lupulović ◽  
Norbert Nowotny

Introduction: This study was conducted to evaluate the seroprevalence of West Nile virus (WNV) in the horse population of northern Serbia. Furthermore, it aimed to provide insight and an updated overview on the circulation of this re-emerging pathogen in this part of southeastern Europe. At the time of manuscript preparation, no clinical cases of WNV infection in horses were reported in this area. Methodology: Between 2007 and 2011, a total of 252 equine serum samples were collected from seven different locations in northern Serbia. The presence of WNV-reactive IgG antibodies was examined by using commercial and in-house ELISAs. Selected ELISA-positive samples were re-tested by a WNV lineage 2 plaque reduction neutralization test 90% (PRNT-90). Results: In 28.6% of the 252 tested equine serum samples antibodies against WNV were detected. The results obtained with the in-house ELISA corresponded to the outcome of the commercial kit in 90% of the samples. All selected WNV antibody ELISA-positive samples were confirmed by PRNT-90 with neutralizing antibody titers of 1:23 to > 1:512. Conclusion: This study confirms the circulation of WNV in northern Serbia. No striking regional differences in seroprevalences were identified suggesting WNV circulation also in other parts of Serbia. Distances between wetlands or forests and stud farms do not appear to have an influence on WNV seroprevalence.


2003 ◽  
Vol 198 (12) ◽  
pp. 1853-1862 ◽  
Author(s):  
Michael S. Diamond ◽  
Elizabeth M. Sitati ◽  
Lindzy D. Friend ◽  
Stephen Higgs ◽  
Bimmi Shrestha ◽  
...  

In humans, the elderly and immunocompromised are at greatest risk for disseminated West Nile virus (WNV) infection, yet the immunologic basis for this remains unclear. We demonstrated previously that B cells and IgG contributed to the defense against disseminated WNV infection (Diamond, M.S., B. Shrestha, A. Marri, D. Mahan, and M. Engle. 2003. J. Virol. 77:2578–2586). In this paper, we addressed the function of IgM in controlling WNV infection. C57BL/6J mice (sIgM−/−) that were deficient in the production of secreted IgM but capable of expressing surface IgM and secreting other immunoglobulin isotypes were vulnerable to lethal infection, even after inoculation with low doses of WNV. Within 96 h, markedly higher levels of infectious virus were detected in the serum of sIgM−/− mice compared with wild-type mice. The enhanced viremia correlated with higher WNV burdens in the central nervous system, and was also associated with a blunted anti-WNV IgG response. Passive transfer of polyclonal anti-WNV IgM or IgG protected sIgM−/− mice against mortality, although administration of comparable amounts of a nonneutralizing monoclonal anti-WNV IgM provided no protection. In a prospective analysis, a low titer of anti-WNV IgM antibodies at day 4 uniformly predicted mortality in wild-type mice. Thus, the induction of a specific, neutralizing IgM response early in the course of WNV infection limits viremia and dissemination into the central nervous system, and protects against lethal infection.


2005 ◽  
Vol 79 (12) ◽  
pp. 7466-7477 ◽  
Author(s):  
Erin Mehlhop ◽  
Kevin Whitby ◽  
Theodore Oliphant ◽  
Anantha Marri ◽  
Michael Engle ◽  
...  

ABSTRACT Infection with West Nile virus (WNV) causes a severe infection of the central nervous system (CNS) with higher levels of morbidity and mortality in the elderly and the immunocompromised. Experiments with mice have begun to define how the innate and adaptive immune responses function to limit infection. Here, we demonstrate that the complement system, a major component of innate immunity, controls WNV infection in vitro primarily in an antibody-dependent manner by neutralizing virus particles in solution and lysing WNV-infected cells. More decisively, mice that genetically lack the third component of complement or complement receptor 1 (CR1) and CR2 developed increased CNS virus burdens and were vulnerable to lethal infection at a low dose of WNV. Both C3-deficient and CR1- and CR2-deficient mice also had significant deficits in their humoral responses after infection with markedly reduced levels of specific anti-WNV immunoglobulin M (IgM) and IgG. Overall, these results suggest that complement controls WNV infection, in part through its ability to induce a protective antibody response.


Sign in / Sign up

Export Citation Format

Share Document