CURRENT STATE OF EQUINE HERPESVIRUS RESEARCH IN ARGENTINA

MARIA BARRANDEGUY; DAMIANI, ARMANDO MARIO

Workshop; 4th Havemeyer workshop on equinbe herpesviruses; 2018

Argentina has a long tradition in breeding horses (Polo and Thoroughbred); thus, particular attention is given to equine herpesvirus infections leading to reproductive disorders, abortion and neonatal disease. In the last two decades, 129 (7%) of the 1791 aborted fetuses received from 819 breeding farms, resulted positive for Equid herpesvirus 1 (EHV-1), with over 95% characterized as non-neuropathogenic A2254 variants. Abortion storms occurred in 20 outbreaks, with the neuropathogenic G2254 variant isolated from 2 outbreaks which were accompanied by neurological clinical signs. Local EHV-1 isolates are being cloned as bacterial artificial chromosomes (BAC) to facilitate genetic studies of variants associated with varied phenotypes in the mouse model. Extensive studies of the pathogenesis, latency and reactivation of Equid Herpesvirus 3 (EHV-3) in the natural host have been taking place in our laboratory since 2007. Recently, efficacy of nucleoside analogues acyclovir, cidofovir and ganciclovir against EHV-3 was evaluated, with the latter being found the most effective compound to reduce viral replication in vitro. To assess the therapeutic efficacy of topical application of ganciclovir in the outcome of EHV-3 infections, research was conducted using 20 experimentally-infected mares. Mutant variants of EHV-3 are generated for potential use as vaccine candidates. Regarding Equid Herpesvirus 4 (EHV-4) infections, the only clinical sign due to this virus that we have observed is respiratory disease in weanling foals. The first outbreak in which EHV-4 was isolated in Argentina was in 1994. Since then, the virus was detected in 20 respiratory disease outbreaks. EHV-4 has been never isolated from cases of respiratory disease in adult horses, abortions or neurological disease.