A 3-year pilot study of sentinel dairy herds for vesicular stomatitis in El Salvador.

The occurrence of vesicular stomatitis (VS) was investigated in El Salvador through monthly visits to 12 sentinel cattle operations located in four different departments. Management, environmental, and spatial data were collected. Heifers were enrolled on the operations and were examined and bled monthly for 3 years. Two competitive ELISAs were used to detect antibodies on each sample for each serotype of VS virus (VSV). On 8 of the 12 operations, small terrestrial rodents were trapped, blood samples collected, and antibodies to both VS serotypes evaluated using a serum-neutralization test for each virus serotype. Similar to other studies of VS in Central America, the seroprevalence of the New Jersey serotype was higher than the seroprevalence to the Indiana serotype. An outbreak of VS appeared to occur in the Department of Sonsonate in the summer of 1999. We confirmed that VS is endemic in the four departments investigated in El Salvador.