Detection of Persistent West Nile Virus RNA in Experimentally and Naturally Infected Avian Hosts

Abstract

Abstract. To determine whether West Nile virus (WNV) persistent infection in avian hosts may potentially serve as an overwintering mechanism, House Sparrows and House Finches, experimentally and naturally infected with several strains of WNV, and two naturally infected Western Scrub-Jays were held in mosquito-proof outdoor aviaries from 2007-March 2008. Overall, 94% (n = 36) of House Sparrows, 100% (n = 14) of House Finches and 2 Western Scrub-Jays remained WNV antibody positive. When combined by species, 37% of the House Sparrows, 50% of the House Finches, and 2 Western Scrub-Jays were WNV RNA positive at necropsy, up to 36 weeks post-infection. Infectious WNV was not detected. Our study supports the hypothesis that some avian hosts support the long-term persistence of WNV RNA, but it remains unresolved whether these infections relapse to restart an avian-arthropod transmission cycle and thereby serve as an overwintering mechanism for WNV.

Development of a strand-specific real-time qRT-PCR for the accurate detection and quantitation of West Nile virus RNA

“…In order to determine permissibility of these cells to infection by WNV, synthesis of the negative strand can be assessed using strand-specific quantitative RT-PCR. Another issue that could be addressed by determining the presence of negative strand is persistence of WNV, which has been described in several organs and animal species (Appler et al, 2010;Murray et al, 2010;Penn et al, 2006;Wheeler et al, 2012;Wu et al, 2008). Specific strand detection can therefore be useful in the elucidation of the mechanisms of persistent infection and may contribute to the further understanding of WNV pathogenesis.…”

Terrestrial Bird Migration and West Nile Virus Circulation, United States

“…WNV RNA has been detected in bird spleen and kidneys as long as 36 weeks after infection ( 10 ) and in brains of Nestor notabilis kea up to 72 months after infection ( 11 ). …”

Detection of Persistent Chikungunya Virus RNA but not Infectious Virus in Experimental Vertical Transmission in Aedes aegypti from Malaysia

“…Long-term persistence of the flavivirus West Nile virus RNA, but not live virus, has been reported in avian hosts up to 36 weeks postinfection. 27 However, it is not known if the virus can recrudesce to render the bird infectious to arthropods once more. Similarly, bluetongue virus RNA but not infectious virus was detected in Culicoides midge larvae from the field.…”