Experimental infection of cliff swallows (Petrochelidon pyrrhonota) with varying doses of West Nile virus.
Cliff swallows (Petrochelidon pyrrhonota) were inoculated with differing doses of West Nile virus (WNV) to evaluate their potential role as reservoir hosts in nature. Swallows often nest in large colonies in habitats and months associated with high mosquito abundance and early WNV transmission in North America. Additionally, cliff swallow diet consists of insects, including mosquitoes, leading to an additional potential route of WNV infection. The average peak viremia titer among infected cliff swallows was 10(6.3) plaque-forming units (PFU)/mL serum and the reservoir competence index was 0.34. There was no correlation between dose and probability of becoming infected or viremia peak and duration. Oral shedding was detected from 2 to 14 days post-inoculation with an average peak titer of 10(4.4) PFU/swab. These results suggest that cliff swallows are competent reservoir hosts of WNV and therefore, they may play a role in early seasonal amplification and maintenance of WNV.
Oesterle
Paul T
PT
United States Department of Agriculture, Wildlife Services, National Wildlife Research Center, Fort Collins, Colorado 80521, USA. Paul.T.Oesterle@aphis.usda.gov
Nemeth
Nicole M
NM
VanDalen
Kaci
K
Sullivan
Heather
H
Bentler
Kevin T
KT
Young
Ginger R
GR
McLean
Robert G
RG
Clark
Larry
L
Smeraski
Cynthia
C
Hall
Jeffrey S
JS
D000818:Animals; D001715:Bird Diseases / Q000821:virology*; D004197:Disease Reservoirs; D046388:Swallows; D014766:Viremia; D017201:Virus Shedding; D014901:West Nile Fever / Q000662:veterinary* / Q000821:virology; D014902:West Nile virus / Q000502:physiology*