Leptospira serology in small ruminants on St. Croix, U.S. Virgin Islands

A serological survey of 16 serovars of Leptospira interrogans, previously reported in tropical small ruminants, was undertaken to determine the serovars involved and the prevalence of these antibodies in sheep and goats on St. Croix, U. S. Virgin Islands (USVI). Seven of eight goat herds (108 animals) had at least two seropositive animals in each herd with an individual animal seroprevalence of 26%. The 53 sheep tested (one flock only) showed a 32% seroprevalence. Antibodies against seven serovars were detected in goats (autumnalis, ballum, bataviae, bratislava, canicola, icterohemorrhagiae, and pyrogenes). In addition, hardjo antibodies were detected in sheep. Serovar autumnalis accounted for about 30% of seropositive animals in each species. Many animals showed titers against more than one serovar. The number of seropositive animals suggests Leptospira may be a factor in the health of small ruminants on St. Croix.