Molecular and serological detection of Leptospira spp. in wildlife from Paraíba, Brazil

Leptospirosis is a widespread zoonotic disease caused by pathogenic Leptospira spp., affecting humans, domestic animals, and wildlife. Wild mammals are recognized as potential maintenance hosts for pathogenic Leptospira spp., and some species may act as asymptomatic reservoirs, representing a potential public health risk, especially in areas with increasing human-wildlife interaction. This cross-sectional study investigated the occurrence of pathogenic Leptospira spp. in wild mammals from Paraíba, Brazil, sampled between June 2022 and June 2023 using serological and molecular approaches. Blood samples from 60 animals were analyzed by the microscopic agglutination test (MAT), while tissue samples from 29 animals were evaluated by polymerase chain reaction (PCR) targeting the lipL32 gene, a marker specific for pathogenic Leptospira spp. Seroreactivity was detected in 9/60 animals (15.0%), with reactions against the serogroups Pomona, Hebdomadis, Grippotyphosa, Shermani, Patoc, and Pyrogenes. Pathogenic Leptospira DNA was detected in 6/29 animals (20.7%), with positive PCR results obtained from multiple tissues, including the kidneys, bladder, liver, brain, and reproductive organs. These findings demonstrate exposure to and infection by pathogenic Leptospira spp. in wild mammals from Paraíba and reinforce the importance of wildlife surveillance for a better understanding of the epidemiology of leptospirosis.