Epidemiological seroprevalence survey of equine influenza virus (eiv) among the carriage horses of Baguio City, Intramuros, Manila, and Tagaytay City

Abstract

Equine influenza virus (EIV) is considered the most important pathogen of horses that causes acute upper respiratory tract diseases. There is no study assessing the prevalence of EIV in animals used for transportation and recreation. This study aimed to assess the seroprevalence of EIV among the carriage horses of Baguio City, Intramuros, Manila, and Tagaytay City. An enzyme-linked immunosorbent assay (ELISA) was used to detect for the presence of antibodies directed against the influenza A internal nucleocapsid in 114 horse sera. Results showed zero prevalence in Tagaytay City, 21.43% in Intramuros, Manila, and 21.52% in Baguio City. Only 13.33% of the horses that had shown presence of ocular and/or nasal discharge are seropositive in ELISA and 90% of theseropositive samples came from horses with no clinical signs at all. The prevalence in males and females were 16.85% and 8.0%, respectively. This study provides baseline information on the occurrence of EIV among domesticated animals used for transportation and recreation. Surveillance of EIV using ELISA may provide a rapid and reliable evaluation of the transmission status of the infection necessary for the improvement and better enforcement of existing policies concerning appropriate surveillance and implementation of control measures. Further studies are needed for better policy formulation and greater assessment of prevalence of EIV in the Philippines.