Comparative fitness of West Nile virus isolated during California epidemics.
West Nile virus (WNV) has been circulating in California since its first detection in 2003, causing repeated outbreaks affecting public, wildlife and veterinary health. Epidemics of WNV are difficult to predict due to the multitude of factors influencing transmission dynamics among avian and mosquit...
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ftdoajarticles:oai:doaj.org/article:189dc89078d04f61a3f3a67e90d3ff20 2023-05-15T15:12:21+02:00 Comparative fitness of West Nile virus isolated during California epidemics. Gabriella Worwa Andra A Hutton Aaron C Brault William K Reisen 2019-02-01T00:00:00Z https://doi.org/10.1371/journal.pntd.0007135 https://doaj.org/article/189dc89078d04f61a3f3a67e90d3ff20 EN eng Public Library of Science (PLoS) https://doi.org/10.1371/journal.pntd.0007135 https://doaj.org/toc/1935-2727 https://doaj.org/toc/1935-2735 1935-2727 1935-2735 doi:10.1371/journal.pntd.0007135 https://doaj.org/article/189dc89078d04f61a3f3a67e90d3ff20 PLoS Neglected Tropical Diseases, Vol 13, Iss 2, p e0007135 (2019) Arctic medicine. Tropical medicine RC955-962 Public aspects of medicine RA1-1270 article 2019 ftdoajarticles https://doi.org/10.1371/journal.pntd.0007135 2022-12-31T05:51:59Z West Nile virus (WNV) has been circulating in California since its first detection in 2003, causing repeated outbreaks affecting public, wildlife and veterinary health. Epidemics of WNV are difficult to predict due to the multitude of factors influencing transmission dynamics among avian and mosquito hosts. Typically, high levels of WNV amplification are required for outbreaks to occur, and therefore associated viral strains may exhibit enhanced virulence and mortality in competent bird species resulting in increased mosquito infection prevalence. In our previous study, most WNV isolates made from California during 2007-08 showed increased fitness when competed in House Finches (HOFI, Haemorhous mexicanus) and Culex tarsalis Coquillett mosquitoes against COAV997-5nt, a genetically marked recombinant virus derived from a 2003 California strain. Herein, we evaluated the competitive fitness of WNV strains isolated during California epidemics in 2004, 2005, 2007, 2011 and 2012 against COAV997-5nt. These outbreak isolates did not produce elevated mortality in HOFIs, but replicated more efficiently than did COAV997-5nt based on quantification of WNV RNA copies in sera, thereby demonstrating increased competitive fitness. Oral co-infections in Cx. tarsalis resulted in similar virus-specific infection and transmission rates, indicating that outbreak isolates did not have a fitness advantage over COAV997-5nt. Collectively, WNV isolates from outbreaks demonstrated relatively greater avian, but not vector, replicative fitness compared to COAV997-5nt, similar to previously characterized non-outbreak isolates of WNV. Our results indicated that ecological rather than viral factors may facilitate WNV amplification to outbreak levels, but monitoring viral phenotypes through competitive fitness studies may provide insight into altered replication and transmission potential among emerging WNV strains. Article in Journal/Newspaper Arctic Directory of Open Access Journals: DOAJ Articles Arctic PLOS Neglected Tropical Diseases 13 2 e0007135 |
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Directory of Open Access Journals: DOAJ Articles |
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English |
topic |
Arctic medicine. Tropical medicine RC955-962 Public aspects of medicine RA1-1270 |
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Arctic medicine. Tropical medicine RC955-962 Public aspects of medicine RA1-1270 Gabriella Worwa Andra A Hutton Aaron C Brault William K Reisen Comparative fitness of West Nile virus isolated during California epidemics. |
topic_facet |
Arctic medicine. Tropical medicine RC955-962 Public aspects of medicine RA1-1270 |
description |
West Nile virus (WNV) has been circulating in California since its first detection in 2003, causing repeated outbreaks affecting public, wildlife and veterinary health. Epidemics of WNV are difficult to predict due to the multitude of factors influencing transmission dynamics among avian and mosquito hosts. Typically, high levels of WNV amplification are required for outbreaks to occur, and therefore associated viral strains may exhibit enhanced virulence and mortality in competent bird species resulting in increased mosquito infection prevalence. In our previous study, most WNV isolates made from California during 2007-08 showed increased fitness when competed in House Finches (HOFI, Haemorhous mexicanus) and Culex tarsalis Coquillett mosquitoes against COAV997-5nt, a genetically marked recombinant virus derived from a 2003 California strain. Herein, we evaluated the competitive fitness of WNV strains isolated during California epidemics in 2004, 2005, 2007, 2011 and 2012 against COAV997-5nt. These outbreak isolates did not produce elevated mortality in HOFIs, but replicated more efficiently than did COAV997-5nt based on quantification of WNV RNA copies in sera, thereby demonstrating increased competitive fitness. Oral co-infections in Cx. tarsalis resulted in similar virus-specific infection and transmission rates, indicating that outbreak isolates did not have a fitness advantage over COAV997-5nt. Collectively, WNV isolates from outbreaks demonstrated relatively greater avian, but not vector, replicative fitness compared to COAV997-5nt, similar to previously characterized non-outbreak isolates of WNV. Our results indicated that ecological rather than viral factors may facilitate WNV amplification to outbreak levels, but monitoring viral phenotypes through competitive fitness studies may provide insight into altered replication and transmission potential among emerging WNV strains. |
format |
Article in Journal/Newspaper |
author |
Gabriella Worwa Andra A Hutton Aaron C Brault William K Reisen |
author_facet |
Gabriella Worwa Andra A Hutton Aaron C Brault William K Reisen |
author_sort |
Gabriella Worwa |
title |
Comparative fitness of West Nile virus isolated during California epidemics. |
title_short |
Comparative fitness of West Nile virus isolated during California epidemics. |
title_full |
Comparative fitness of West Nile virus isolated during California epidemics. |
title_fullStr |
Comparative fitness of West Nile virus isolated during California epidemics. |
title_full_unstemmed |
Comparative fitness of West Nile virus isolated during California epidemics. |
title_sort |
comparative fitness of west nile virus isolated during california epidemics. |
publisher |
Public Library of Science (PLoS) |
publishDate |
2019 |
url |
https://doi.org/10.1371/journal.pntd.0007135 https://doaj.org/article/189dc89078d04f61a3f3a67e90d3ff20 |
geographic |
Arctic |
geographic_facet |
Arctic |
genre |
Arctic |
genre_facet |
Arctic |
op_source |
PLoS Neglected Tropical Diseases, Vol 13, Iss 2, p e0007135 (2019) |
op_relation |
https://doi.org/10.1371/journal.pntd.0007135 https://doaj.org/toc/1935-2727 https://doaj.org/toc/1935-2735 1935-2727 1935-2735 doi:10.1371/journal.pntd.0007135 https://doaj.org/article/189dc89078d04f61a3f3a67e90d3ff20 |
op_doi |
https://doi.org/10.1371/journal.pntd.0007135 |
container_title |
PLOS Neglected Tropical Diseases |
container_volume |
13 |
container_issue |
2 |
container_start_page |
e0007135 |
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1766343045599461376 |