Meta-analysis of published frequencies of the first decade of field-based mortality and seropositivity in avian species affected by West Nile virus in the United States
- Published
- Accepted
- Subject Areas
- Veterinary Medicine, Epidemiology, Global Health, Infectious Diseases
- Keywords
- West Nile virus, birds, meta-analysis, seropositivity, mortality, flavivirus, reservoir host, Blomberg's K, phylogenetic difference
- Copyright
- © 2016 Verdugo et al.
- Licence
- This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, reproduction and adaptation in any medium and for any purpose provided that it is properly attributed. For attribution, the original author(s), title, publication source (PeerJ PrePrints) and either DOI or URL of the article must be cited.
- Cite this article
- 2016. Meta-analysis of published frequencies of the first decade of field-based mortality and seropositivity in avian species affected by West Nile virus in the United States. PeerJ PrePrints 4:e1665v1 https://doi.org/10.7287/peerj.preprints.1665v1
Abstract
A meta-analysis approach was used to extract the frequency of avian seropositivity to West Nile Virus (WNV) (fS) and mortality from WNV (fM) from the literature published between the years 2001-2010. The indices, fS and fM, were used to represent states of resistance (seropositivity with no or limited mortality) and susceptibility in birds (detection of WNV with mortality), respectively. The indices fS and fM were calculated for each species across publications into different taxonomic strata, year, combined time intervals, and geographic location. The data were analyzed by logistic regression to assess the status of WNV infection amongst different avian taxonomic strata and infer changes of WNV infection status over time. Using level of peak viremia as a proxy for host competence among the avian species, the value of the phylogenetic signal was tested by Blomberg´s K after transformation of the branch lengths. Sixty-three publications were used for the final dataset representing studies performed from 1999 to 2008 and published between 2001-2010. Analysis of both fS and fM demonstrated variability in avian responses to WNV across order, family, and species. When the data were analyzed for fS, the families and species of the orders Ciconiiformes, Galliformes, and Columbiformes had significantly higher fS than that of the Passeriformes (P < 0.0001). Within the Passeriformes, the Corvidae and Cardinalidae families had higher fS than any other family. When the data were analyzed for fM, dead Corvidae and Paridae were most likely to test positive for virus. Temporally, a positive trend of increasing fS was detected in several avian species while the American crow (Corvus brachyrhynchos) was the only species with a significant negative trend in fM (P = 0.042). Little to no interaction of geographic location with time was detected within species of birds. A weak but significant phylogenetic signal corresponded to host range, suggesting that the rate of spread of WNV through the avian community was partially dependent of the relatedness of hosts. The meta-data predicted that species within families, and even order, were heterogeneous in their disease susceptibility traits to WNV. The Passeriformes contributed most to this variation. Several trends in various families and orders of birds were observed from which new studies could be pursued. The pooling of data was key in detecting areas where data was lacking and identified aspects of avian responses to WNV could be expanded.
Author Comment
This is a preprint submission to PeerJ Preprints.