Vectorial Competence Potential of Culex Quinquefasciatus (Say, 1923) from the Amazon Region to Transmit West Nile Virus Isolated in Brazil

2021 ◽  
Author(s):  
Lúcia Aline Moura Reis ◽  
Eliana Vieira Pinto da Silva ◽  
Maria Nazaré Oliveira Freitas ◽  
Rossela Damasceno Caldeira ◽  
Pedro Arthur da Silva Araújo ◽  
...  
Keyword(s):  
West Nile Virus ◽  
Culex Quinquefasciatus ◽  
Transmission Rate ◽  
Amazon Region ◽  
West Nile Fever ◽  
West Nile ◽  
Potential Vector ◽  
Brazilian Strain ◽  
Vectorial Competence ◽  
Viral Titers

Abstract The West Nile virus is characterized as a neurotropic pathogen that causes the West Nile fever. It is transmitted by mosquitoes, mainly of the Culex genus. In 2018, the Evandro Chagas Institute carried out the first isolation of WNV strain from a horse brain sample and in 2021 the same institute also isolated the WNV in a pool of mosquitoes of the Culex spp. from the Carajás region (Pará). Thus, this study aimed to determine the vectorial competence of Culex quinquefasciatus from the Amazon region of Brazil for transmission the WNV Brazilian strain. Oral infection of Cx. quinquefasciatus females belonging to F1 generation was performed with infected blood with WNV. Subsequently, analysis of infection, dissemination and transmission rates was performed, as well as verification of viral titers in the samples. The study demonstrated that Cx. quinquefasciatus can act as a potential vector of WNV in Brazil, since it was found that the Brazilian strain was able to overcome the host's anatomical barriers and spread to various regions, among them in saliva, in which, despite the low viral titers identified, it had a transmission rate of 100% on the 21st day after infection.

scholarly journals Increase in human West Nile and Usutu virus infections, Austria, 2018

2018 ◽  
Vol 23 (43) ◽  
Author(s):  
Stephan W. Aberle ◽  
Jolanta Kolodziejek ◽  
Christof Jungbauer ◽  
Karin Stiasny ◽  
Judith H. Aberle ◽  
...  
Keyword(s):  
West Nile Virus ◽  
Blood Donors ◽  
Blood Donation ◽  
Virus Infections ◽  
West Nile Fever ◽  
West Nile ◽  
Usutu Virus ◽  
Neuroinvasive Disease ◽  
Human West Nile Virus ◽  
Imported Cases

Between 28 June and 17 September 2018, 27 cases of human West Nile virus infections were recorded in Austria; four cases of West Nile neuroinvasive disease, 11 cases of West Nile fever, six infections detected by blood donation screening and six imported cases. In addition, 18 cases of human Usutu virus infections (all blood donors) were recorded. This is the highest number of annual infections recorded in Austria since the introduction of both viruses.

scholarly journals Human cases of West Nile Virus Infection in north-eastern Italy, 15 June to 15 November 2010

2011 ◽  
Vol 16 (33) ◽  
Author(s):  
L Barzon ◽  
M Pacenti ◽  
R Cusinato ◽  
M Cattai ◽  
E Franchin ◽  
...  
Keyword(s):  
West Nile Virus ◽  
West Nile Virus Infection ◽  
West Nile Fever ◽  
Antibody Prevalence ◽  
Igg Antibody ◽  
West Nile ◽  
The Third ◽  
Neuroinvasive Disease ◽  
Northern Areas ◽  
North Eastern

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.

scholarly journals WEST NILE FEVER IN THE SARATOV REGION IN 2013-2015

2017 ◽  
Vol 62 (5) ◽  
pp. 219-226
Author(s):  
E. V. Kazorina ◽  
T. Yu. Krasovskaya ◽  
A. V. Kazantsev ◽  
E. V. Naydenova ◽  
I. N. Sharova ◽  
...  
Keyword(s):  
West Nile Virus ◽  
Clinical Samples ◽  
West Nile Fever ◽  
West Nile ◽  
Saratov Region ◽  
Stable Domain ◽  
Field Samples ◽  
Live Stock ◽  
Regional Population ◽  
The City

West Nile virus (WNV) circulation in the territory of Saratov region and its role in the infectious pathology were investigated. For this purpose, in studies conducted in 2013-2015, suspensions of bloodsucking arthropods, organs of birds and small mammals were analyzed for the presence of WNV markers (antigens and/or RNA). The seroprevalence level in live-stock animals and population of the region was evaluated; clinical samples from patients with symptoms compatible with West Nile fever (WNF) were analyzed. As a result of the investigations, WNV markers were detected in field samples gathered in natural biotopes and in the city of Saratov. Immunity to WNV was detected in horses. A stable domain of persons with immunity to this agent was revealed among regional population. Patients with WNF have been annually registered in the region since 2012. The obtained results confirm active circulation of WNF in the Saratov region, as well as formation of stable natural and anthropourgic foci.

scholarly journals Insecticide resistance genes affect Culex quinquefasciatus vector competence for West Nile virus

2019 ◽  
Vol 286 (1894) ◽  
pp. 20182273 ◽  
Author(s):  
Célestine M. Atyame ◽  
Haoues Alout ◽  
Laurence Mousson ◽  
Marie Vazeille ◽  
Mawlouth Diallo ◽  
...  
Keyword(s):  
West Nile Virus ◽  
Insecticide Resistance ◽  
Culex Quinquefasciatus ◽  
Rift Valley Fever Virus ◽  
Vector Competence ◽  
Resistance Mechanisms ◽  
Transmission Efficiency ◽  
West Nile ◽  
Valley Fever ◽  
Resistant Lines

Insecticide resistance has been reported to impact the interactions between mosquitoes and the pathogens they transmit. However, the effect on vector competence for arboviruses still remained to be investigated. We examined the influence of two insecticide resistance mechanisms on vector competence of the mosquito Culex quinquefasciatus for two arboviruses, Rift Valley Fever virus (RVFV) and West Nile virus (WNV). Three Cx. quinquefasciatus lines sharing a common genetic background were used: two insecticide-resistant lines, one homozygous for amplification of the Ester 2 locus (SA2), the other homozygous for the acetylcholinesterase ace-1 G119S mutation (SR) and the insecticide-susceptible reference line Slab. Statistical analyses revealed no significant effect of insecticide-resistant mechanisms on vector competence for RVFV. However, both insecticide resistance mechanisms significantly influenced the outcome of WNV infections by increasing the dissemination of WNV in the mosquito body, therefore leading to an increase in transmission efficiency by resistant mosquitoes. These results showed that insecticide resistance mechanisms enhanced vector competence for WNV and may have a significant impact on transmission dynamics of arboviruses. Our findings highlight the importance of understanding the impacts of insecticide resistance on the vectorial capacity parameters to assess the overall consequence on transmission.

Experimental Studies on Comparison of the Potential Vector Competence of Four Species of Culex Mosquitoes in China to Transmit West Nile Virus

2010 ◽  
Vol 47 (5) ◽  
pp. 788-790 ◽  
Author(s):  
Shu-Fang Jiang ◽  
Ying-Mei Zhang ◽  
Xiao-Xia Guo ◽  
Yan-De Dong ◽  
Dan Xing ◽  
...  
Keyword(s):  
West Nile Virus ◽  
Vector Competence ◽  
Experimental Studies ◽  
West Nile ◽  
Potential Vector

scholarly journals Key Factors Influencing the Incidence of West Nile Virus in Burleigh County, North Dakota

2018 ◽  
Vol 15 (9) ◽  
pp. 1928 ◽  
Author(s):  
Hiroko Mori ◽  
Joshua Wu ◽  
Motomu Ibaraki ◽  
Franklin Schwartz
Keyword(s):  
West Nile Virus ◽  
North Dakota ◽  
Transmission Rate ◽  
Virus Transmission ◽  
Correlation Coefficients ◽  
West Nile ◽  
Mosquito Abundance ◽  
River Flooding ◽  
Disease Case ◽  
The City

The city of Bismarck, North Dakota has one of the highest numbers of West Nile Virus (WNV) cases per population in the U.S. Although the city conducts extensive mosquito surveillance, the mosquito abundance alone may not fully explain the occurrence of WNV. Here, we developed models to predict mosquito abundance and the number of WNV cases, independently, by statistically analyzing the most important climate and virus transmission factors. An analysis with the mosquito model indicated that the mosquito numbers increase during a warm and humid summer or after a severely cold winter. In addition, river flooding decreased the mosquito numbers. The number of WNV cases was best predicted by including the virus transmission rate, the mosquito numbers, and the mosquito feeding pattern. This virus transmission rate is a function of temperature and increases significantly above 20 °C. The correlation coefficients (r) were 0.910 with the mosquito-population model and 0.620 with the disease case model. Our findings confirmed the conclusions of other work on the importance of climatic variables in controlling the mosquito numbers and contributed new insights into disease dynamics, especially in relation to extreme flooding. It also suggested a new prevention strategy of initiating insecticides not only based on mosquito numbers but also 10-day forecasts of unusually hot weather.

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