West Nile virus encephalomyelitis in eight horses

Detection of West Nile virus using formalin fixed paraffin embedded tissues in crows and horses: quantification of viral transcripts by real-time RT-PCR

“…A monoclonal antibody based enzyme immunosorbent assay that distinguishes WNV from other flaviviruses has now also become available (Hunt et al, 2002). In horses, the disease runs mainly a neurologic course and 60%-70% of the infected horses have been reported to recover from this infection (Bunning et al, 2001Cantile et al, 2001;Snook et al, 2001;Trock et al, 2001). To investigate WNV pathogenesis in horses, we have used a real-time RT-PCR with a Taqman probe for examining tissue distribution of viral transcripts.…”

Incidence and effects of West Nile virus infection in vaccinated and unvaccinated horses in California

“…In 1999, WNV was first detected in North America in New York, and subsequently the virus spread throughout Canada, the USA, Mexico and the Caribbean [13,14,21]. Horses have been the mammalian species most impacted during the current epidemic of WNV infection in North America, with attendant high morbidity and mortality [20,22,[25][26][27][28]. WNV was not detected in California until July 2003, when the virus was identified in Culex tarsalis mosquitoes in the Imperial Valley of southeastern California [24].…”

Diagnosis of West Nile Virus Infection in Horses

“…From a population of over 500 horses in which WNV infection was suspected based on clinical signs, 5,16,17,[20][21][22][23] RTnPCR was performed on RNA extracted from ethylenediaminetetraacetic acid-anticoagulated blood of 140 horses. None of the 140 horses was previously vaccinated against WNV.…”

“…Diagnosis of WNV in horses is currently based on observation of compatible clinical signs, such as ataxia, paresis, paralysis, hyperesthesia, muscle fasciculations, seizures, or fever 5,16,17,[21][22][23] and on one or more of the following: isolation or reverse transcriptasepolymerase chain reaction (RT-PCR) detection of WNV from tissue, blood, or cerebrospinal fluid (CSF); a 4-fold increase in plaque reduction neutralization test (PRNT) antibody titers between paired serum samples taken 2 weeks apart; detection of IgM antibody to WNV by IgM-capture enzyme-linked immunosorbent assay (ELISA) or a neutralizing titer of Ͼ1:10 by PRNT in a single serum sample. However, widespread use of a WNV vaccine coupled with multiple years of natural exposure may make interpretation of PRNT serological results less definitive.…”