Greater Sage-Grouse survival varies with breeding season events in West Nile virus non-outbreak years

The Condor ◽  
2021 ◽  
Author(s):  
Lindsey A Parsons ◽  
Travis J Runia ◽  
Geoffrey P Vincent ◽  
Andrew J Gregory ◽  
Jonathan A Jenks
Keyword(s):  
West Nile Virus ◽  
South Dakota ◽  
Breeding Season ◽  
Mosquito Species ◽  
Sage Grouse ◽  
West Nile ◽  
Species Of Conservation Concern ◽  
Mammalian Predators ◽  
Antibody Titers ◽  
Conservation Concern

Abstract Greater Sage-Grouse (Centrocercus urophasianus) is a species of conservation concern and is highly susceptible to mortality from West Nile virus (WNV). Culex tarsalis, a mosquito species, is the suspected primary vector for transmitting WNV to sage-grouse. We captured, radio-tagged, and monitored female sage-grouse to estimate breeding season (April 15 to September 15) survival, 2016–2017. Deceased sage-grouse were tested for active WNV; live-captured and hunter-harvested sage-grouse were tested for WNV antibody titers. Additionally, we trapped mosquitoes with CO2-baited traps 4 nights per week (542 trap nights) to estimate WNV minimum infection rate (MIR). Eight sage-grouse mortalities occurred during the WNV seasons of 2016 and 2017, 5 had recoverable tissue, and 1 of 5 tested positive for WNV infection. Survival varied temporally with sage-grouse biological seasons, not WNV seasonality. Survival was 0.68 (95% CI: 0.56–0.78; n = 74) during the reproductive season (April 1 to September 15). Mammalian predators were the leading suspected cause of mortality (40%), followed by unknown cause (25%), avian predation (15%), unknown predation (15%), and WNV (5%). These results indicate WNV was not a significant driver of adult sage-grouse survival during this study. Three sage-grouse (1.9%; 95% CI: 0.5–5.9%) contained WNV antibodies. We captured 12,472 mosquitoes of which 3,933 (32%) were C. tarsalis. The estimated WNV MIR of C. tarsalis during 2016 and 2017 was 3.3 and 1.6, respectively. Our results suggest sage-grouse in South Dakota have limited exposure to WNV, and WNV was not a significant source of sage-grouse mortality in South Dakota during 2016 and 2017. Based on our finding that a majority of sage-grouse in South Dakota are susceptible to WNV infection, WNV could potentially have an impact on the population during an epizootic event; however, when WNV is at or near-endemic levels, it appears to have little impact on sage-grouse survival.

scholarly journals Epidemic West Nile Virus Infection Rates and Endemic Population Dynamics Among South Dakota Mosquitoes: A 15-yr Study from the United States Northern Great Plains

2019 ◽  
Vol 57 (3) ◽  
pp. 862-871
Author(s):  
Geoffrey P Vincent ◽  
Justin K Davis ◽  
Matthew J Wittry ◽  
Michael C Wimberly ◽  
Chris D Carlson ◽  
...  
Keyword(s):  
United States ◽  
West Nile Virus ◽  
South Dakota ◽  
Relative Abundance ◽  
Mosquito Species ◽  
Abundant Species ◽  
The United States ◽  
Northern Great Plains ◽  
Infection Rates ◽  
West Nile

Abstract Mosquito surveillance has been conducted across South Dakota (SD) to record and track potential West Nile virus (WNV) vectors since 2004. During this time, communities from 29 counties collected nearly 5.5 million mosquitoes, providing data from over 60,000 unique trapping nights. The nuisance mosquito, Aedes vexans (Meigen) was the most abundant species in the state (39.9%), and most abundant in most regions. The WNV vector, Culex tarsalis Coquillett (Diptera: Culicidae), was the second most abundant species (20.5%), and 26 times more abundant than the other Culex species that also transmit WNV. However, geographic variation did exist between WNV vector species, as well as relative abundance of vector and nuisance mosquitoes. The abundance of Ae. vexans decreased from east to west in South Dakota, resulting in an increase in the relative abundance of Cx. tarsalis. Other species are reported in this study, with various relative abundances throughout the different regions of South Dakota. WNV infection rates of mosquitoes showed that Cx. tarsalis had the most positive sampling pools and the highest vector index of all the species tested. This study addressed the need for an updated summary of the predominant mosquito species present in the United States Northern Great Plain and provides infection rate data for WNV among these predominant species.

scholarly journals Population dynamics of mosquito species in a West Nile virus endemic area in Madagascar

Parasite ◽  
2017 ◽  
Vol 24 ◽  
pp. 3 ◽  
Author(s):  
Luciano Michaël Tantely ◽  
Catherine Cêtre-Sossah ◽  
Tsiriniaina Rakotondranaivo ◽  
Eric Cardinale ◽  
Sébastien Boyer
Keyword(s):  
Population Dynamics ◽  
West Nile Virus ◽  
Endemic Area ◽  
Mosquito Species ◽  
West Nile

scholarly journals Epidemiology of West Nile virus in Africa: An underestimated threat

2022 ◽  
Vol 16 (1) ◽  
pp. e0010075
Author(s):  
Giulia Mencattelli ◽  
Marie Henriette Dior Ndione ◽  
Roberto Rosà ◽  
Giovanni Marini ◽  
Cheikh Tidiane Diagne ◽  
...  
Keyword(s):  
West Nile Virus ◽  
Disease Burden ◽  
Vector Competence ◽  
Mosquito Species ◽  
Global Scale ◽  
Reference List ◽  
African Continent ◽  
West Nile ◽  
Scientific Papers ◽  
Epidemiological Pattern

Background West Nile virus is a mosquito-borne flavivirus which has been posing continuous challenges to public health worldwide due to the identification of new lineages and clades and its ability to invade and establish in an increasing number of countries. Its current distribution, genetic variability, ecology, and epidemiological pattern in the African continent are only partially known despite the general consensus on the urgency to obtain such information for quantifying the actual disease burden in Africa other than to predict future threats at global scale. Methodology and principal findings References were searched in PubMed and Google Scholar electronic databases on January 21, 2020, using selected keywords, without language and date restriction. Additional manual searches of reference list were carried out. Further references have been later added accordingly to experts’ opinion. We included 153 scientific papers published between 1940 and 2021. This review highlights: (i) the co-circulation of WNV-lineages 1, 2, and 8 in the African continent; (ii) the presence of diverse WNV competent vectors in Africa, mainly belonging to the Culex genus; (iii) the lack of vector competence studies for several other mosquito species found naturally infected with WNV in Africa; (iv) the need of more competence studies to be addressed on ticks; (iv) evidence of circulation of WNV among humans, animals and vectors in at least 28 Countries; (v) the lack of knowledge on the epidemiological situation of WNV for 19 Countries and (vii) the importance of carrying out specific serological surveys in order to avoid possible bias on WNV circulation in Africa. Conclusions This study provides the state of art on WNV investigation carried out in Africa, highlighting several knowledge gaps regarding i) the current WNV distribution and genetic diversity, ii) its ecology and transmission chains including the role of different arthropods and vertebrate species as competent reservoirs, and iii) the real disease burden for humans and animals. This review highlights the needs for further research and coordinated surveillance efforts on WNV in Africa.

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.

Vector Competence of Australian Mosquito Species for a North American Strain of West Nile Virus

2008 ◽  
Vol 8 (6) ◽  
pp. 805-812 ◽  
Author(s):  
Cassie C. Jansen ◽  
Cameron E. Webb ◽  
Judith A. Northill ◽  
Scott A. Ritchie ◽  
Richard C. Russell ◽  
...  
Keyword(s):  
West Nile Virus ◽  
North American ◽  
Vector Competence ◽  
Mosquito Species ◽  
West Nile ◽  
North American Strain ◽  
American Strain
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