Bird Species Involved in West Nile Virus Epidemiological Cycle in Southern Québec.

Ludivine Taieb,Carl A Gagnon,Nick H Ogden,Antoinette Ludwig,Dominique J Bicout,Robbin L Lindsay,Mahmood Iranpour

doi:10.3390/ijerph17124517

Abstract

Despite many studies on West Nile Virus (WNV) in the US, including the reservoir role of bird species and the summer shifts of the Culex mosquito, feeding from birds to mammals, there have been few equivalent studies in the neighboring regions of Canada where WNV is endemic. Here, a priority list of bird species likely involved in WNV transmission in the greater Montréal area is constructed by combining three sources of data: (i) from WNV surveillance in wild birds (2002–2015); (ii) blood meal analysis of Culex pipiens–restuans (CPR), the primary enzootic vectors of WNV in the region, collected from surveillance in 2008 and 2014; (iii) literature review on the sero-prevalence/host competence of resident birds. Each of these data sources yielded 18, 23 and 53 species, and overall, 67 different bird species were identified as potential WNV amplifiers/reservoirs. Of those identified from CPR blood meals, Common starlings, American robins, Song sparrows and House sparrows ranked the highest and blood meal analysis demonstrated a seasonal shift in feed preference from birds to mammals by CPR. Our study indicates that there are broad similarities in the ecology of WNV between our region and the northeastern US, although the relative importance of bird species varies somewhat between regions.

Highlights

First described in Uganda in 1937 [1], West Nile Virus (WNV) is an arbovirus of the Flaviviridae virus family, genus Flavivirus
We found a list L = 53 that was sorted based on the relative ratio of sero-positives, as shown in Figure 7, as follows: 22 bird species were found most often sero-positive for WNV and the top five species were Red-shouldered hawk, Merlin, Green heron, Eastern meadowlark and Cooper’s hawk
The distribution of the species we identified among the lists is as follows: L1 = 18, L2 = 23 and L3 = 53 with the number of common species, L1 ∩ L2 = 2, L1 ∩ L3 = 7 and L2 ∩ L3 = 20, and L1 ∩ L2 ∩ L3 = 2 species (American crow and Cooper’s hawk) belonging to all three lists

Summary

Introduction

First described in Uganda in 1937 [1], West Nile Virus (WNV) is an arbovirus of the Flaviviridae virus family, genus Flavivirus. It has a transmission cycle involving mosquitoes as vectors and birds as amplifying hosts or reservoirs, with humans and horses being primarily dead-end hosts [2,3]. The early symptoms of WNV include fever, headache, skin rash, nausea and muscle aches. Most of the affected people recover fully, but approximately 1% develops severe illness Res. Public Health 2020, 17, 4517; doi:10.3390/ijerph17124517 www.mdpi.com/journal/ijerph

Objectives

Methods

Discussion

Conclusion