Leptospira Species Infection and Seropositivity in Domestic Livestock and Feral Swine in Puerto Rico.

Leptospirosis is a zoonotic disease of global importance that significantly impacts human health and the livestock industry. In Puerto Rico, outbreaks of leptospirosis in humans have been associated with hurricanes and subsequent flooding events. Rodent species in Puerto Rico and feral swine in the continental United States have been implicated as reservoir hosts for Leptospira species and serogroups, with the possibility of transmitting the pathogen to humans. In this cross-sectional investigation, we collected samples from 670 animals, including 375 feral swine, 168 transitional swine, 120 dairy cattle, six beef cattle, and one small ruminant to assess Leptospira spp. exposure and infection in specific regions of Puerto Rico. Of all animals sampled and tested, 55.82% (n = 374) had a positive result to at least one of the following leptospirosis tests performed: microscopic agglutination test (MAT), polymerase chain reaction (PCR), fluorescent antibody test (FAT), and/or culture. Of all animals from which serum samples were tested, 75.90% (n = 126) of transitional swine, 78.72% (n = 37) of dairy cattle, 100% (n = 4) of beef cattle, and 53.13% (n = 195) of feral swine had detectable Leptospira antibodies on MAT. Of all animals from which urine samples were collected and tested on either lipL32 PCR or FAT, 0% of transitional swine, 22.86% (n = 24) of dairy cattle, 16.67% (n = 1) of beef cattle, and 1.71% (n = 2) of feral swine tested positive for Leptospira species on one or both of these tests. L. borgpetersenii serogroup Sejroe serovar Hardjo was isolated from the urine of two dairy cows, and L. santarosai serogroup Pyrogenes was isolated from the urine of another dairy cow. The findings of this investigation provide valuable information on the circulating Leptospira species, serogroups, and serovars in domestic livestock and feral swine in specific regions of Puerto Rico and will further inform human and animal disease prevention, preparedness, and response.