A systematic review of Leptospira and leptospirosis in wildlife: A global perspective

There are many different pathogenic species of Leptospira that circulate among a wide range of wild and domestic animals. Certain species and serovars can cause disease in some hosts but not in others. Although leptospirosis has been extensively studied in humans and domestic animals, with its epidemiology and economic impact being well characterized, much less is known about its ecological dynamics in wildlife. The host-pathogen associations, transmission pathways, and disease outcomes in wild animal populations remain poorly understood. This review summarizes the current evidence on Leptospira and leptospirosis in wildlife, identifying methodological biases and highlighting key knowledge gaps. It also compiles information on wild animal species in which exposure to the pathogen has been documented. A systematic search of the scientific literature published between 2000 and 2025 was performed across multiple databases in accordance with PRISMA guidelines. Following screening and an assessment of eligibility, data were extracted from 389 peer-reviewed articles reporting exposure to, infection with, or detection of the pathogen in wildlife species worldwide. An analysis of study locations and publication trends was also performed. The reviewed studies revealed substantial heterogeneity in diagnostic methods, sampling effort, and geographic coverage, as well as a wide taxonomic diversity of wildlife species exposed to or infected with Leptospira. Clinical cases were most frequently reported in the orders Carnivora and Rodentia, with mortality documented in marine mammals, large felids and primates, particularly in untreated cases. Analysis of carriage and exposure studies revealed a strong sampling bias toward mammals compared to birds and reptiles. Molecular detection was reported in 155 articles, with lipL32 being the most commonly used marker. Sequencing of amplicons enabled identification of Leptospira at the level of the species. Meanwhile, serological testing predominantly relied on MAT reporting.