Cross-sectional evaluation of multiple epidemiological cycles of Leptospira species in peri-urban wildlife in California

OBJECTIVE To perform a cross-sectional survey to estimate prevalence of and potential risk factors for Leptospira spp infection and exposure in peri-urban wildlife throughout California. ANIMALS 723 animals representing 12 wildlife species. PROCEDURES Blood and urine samples were obtained from wildlife in California from 2007 to 2017. Live animals were captured in humane traps, anesthetized, and released. Carcasses were donated by wildlife services and necropsied for urine, blood, and kidney tissue samples. Samples were tested for antibodies against 6 serovars of Leptospira spp with a microscopic agglutination test and for pathogenic Leptospira spp DNA with a real-time PCR assay targeting the LipL32 gene. Potential risk factors for Leptospira spp exposure were assessed by logistic regression. Genetic relatedness of Leptospira spp were assessed with DNA sequencing of the rrs2 gene and multiple locus sequence analysis. RESULTS Statewide Leptospira spp seroprevalence was 39.1%, and prevalence of positive PCR assay results for Leptospira spp DNA was 23.0%. Risk factors for Leptospira spp exposure included being an adult, being from northern California, and being a western gray squirrel, coyote, striped skunk, raccoon, gray fox, or mountain lion. Antibodies against serovar Pomona predominated in most species, followed by serovar Copenhageni. Complete rrs2 sequences were identified as Leptospira interrogans and multiple locus sequence type analysis revealed sequence type 140. CONCLUSIONS AND CLINICAL RELEVANCE Pathogenic Leptospira spp appeared to be common and widespread among peri-urban wildlife in California. Our data highlight the potential for exposure to infectious disease for both humans and domestic animals at the urban-wildland interface.