Evidence of foot-and-mouth disease virus excretion in the milk of apparently healthy vaccinated buffaloes in Islamabad, Pakistan

Abstract

The aim of the study was to determine the seroprevalence of foot-and-mouth disease (FMD) and isolation of the FMD virus (FMDV) in the milk of apparently healthy Asian buffaloes. A cross-sectional study was conducted in periurban dairy farms (n = 20) on ≥ 20 animals per farm in the suburbs of Islamabad, Pakistan. Sera samples (n = 200) were collected to monitor FMDV seroconversions. The analysis of serum samples using ELISA indicated a high seroprevalence of FMD (78%; 156/200) in Asian buffaloes. Milk samples were collected from FMDV seropositive animals only, and virus-specific signals were detected in 12.2% (19/156) of the animals by reverse transcriptase real-time PCR (rRT-PCR). Milk samples positive for FMDV using rRT-PCR were inoculated into LF-BK cells for virus isolation. Two FMDV isolates (serotypes O and Asia-1) were recovered from the milk samples. A high seroprevalence of FMD and isolation of FMDV from the milk of healthy Asian buffaloes may represent a possible role for healthy Asian buffaloes as an FMD reservoir.