Leptospira species infection and seropositivity in domestic livestock and feral swine in Puerto Rico

Authors: DIRSMITH, KATHERINE - Animal And Plant Health Inspection Service (APHIS); Nally, Jarlath; SUTHERLAND, GRAHAM - Centers For Disease Control And Prevention (CDC) - United States; HAMOND, CAMILA - Diagnostic Virology Laboratory/ National Veterinary Services Laboratories; GALLOWAY, RENEE - Centers For Disease Control And Prevention (CDC) - United States; LECOUNT, KAREN - Diagnostic Virology Laboratory/ National Veterinary Services Laboratories; ANDERSON, TAMMY - Diagnostic Virology Laboratory/ National Veterinary Services Laboratories; SOLTERO, FRED - Animal And Plant Health Inspection Service (APHIS); RIVERA-GARCIA, SARAI - Animal And Plant Health Inspection Service (APHIS); NOVAK, VICTORIA - Animal And Plant Health Inspection Service (APHIS); OLIVIERI-CINTRON, GUSTAVO - Animal And Plant Health Inspection Services (APHIS), National Wildlife Center; GRUVER, KENNETH - Animal And Plant Health Inspection Services (APHIS), National Wildlife Center; BROWN, VIENNA - Animal And Plant Health Inspection Services (APHIS), National Wildlife Center; GLASSEY, CLAYTON - Animal And Plant Health Inspection Services (APHIS), National Wildlife Center; MCKINLEY, A. SHANE - Animal And Plant Health Inspection Services (APHIS), National Wildlife Center; CANDELARIA, ONIEL - Animal And Plant Health Inspection Services (APHIS), National Wildlife Center; STEPHENS, LEIF - Animal And Plant Health Inspection Services (APHIS), National Wildlife Center; SCHAFER, ILANA - Centers For Disease Control And Prevention (CDC) - United States

Submitted to: Transboundary and Emerging Diseases
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 3/26/2026
Publication Date: 5/27/2026
Citation: Dirsmith, K.L., Nally, J.E., Sutherland, G., Hamond, C., Galloway, R.L., LeCount, K., Anderson, T., Soltero, F.V., Rivera-Garcia, S., Novak, V., Olivieri-Cintron, G.E., Gruver, K., Brown, V.R., Glassey, C., McKinley, A., Candelaria, O., Stephens, L., Schafer, I.J. 2026. Leptospira species infection and seropositivity in domestic livestock and feral swine in Puerto Rico. Transboundary and Emerging Diseases. https://doi.org/10.1155%2Ftbed%2F2538118.
DOI: https://doi.org/10.1155%2Ftbed%2F2538118

Interpretive Summary: Leptospirosis is an infectious bacterial disease that infects humans and animals and is endemic in the U.S. and its protectorates. Domestic and wildlife animals act as reservoir hosts of infection and shed the causative agent, pathogenic species of Leptospira, via urine into the environment where they can persist in suitable moist conditions. In Puerto Rico, outbreaks of leptospirosis in humans have been associated with hurricanes and subsequent flooding events. In this study, domestic and wildlife animal species in Puerto Rico were tested to determine if they showed evidence of infection with Leptospira. Urine samples were collected and results indicated that 0% of transitional swine, 22.86% (n=24) of dairy cattle, 16.67% (n=1) of beef cattle, and 28.57% (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 study provide valuable information on the circulating Leptospira species, serogroups, and serovars in domestic livestock and feral swine in Puerto Rico and will further inform human and animal disease prevention, preparedness, and response.

Technical Abstract: 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 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 the prevalence and distribution of Leptospira spp. exposure and infection in Puerto Rico. Of all animals sampled and tested, 55.97% (n=375) 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 study provide valuable information on the circulating Leptospira species, serogroups, and serovars in domestic livestock and feral swine in Puerto Rico and will further inform human and animal disease prevention, preparedness, and response.