A four-year serological survey of Leptospira spp. in stray dogs from northwest Mexico

The presence of stray dogs in a community represents a significant risk factor in the spread and maintenance of Leptospira by acting as pathogen reservoirs and potentially transmitting the bacteria to household dogs and the peri-domestic environment, increasing the risk of zoonotic transmission of the disease. Here, we utilized an indirect ELISA employing recombinant LipL32 protein to detect IgG antibodies to Leptospira in serum samples from stray dogs in Mexicali, Northwest Mexico. Serum samples (n = 331) from stray dogs were collected from 2017 to 2020 and tested with the ELISA-LipL32. The results showed an overall seroprevalence of 46.52 % (154/331) over the four years, 46.36 % (51/110) in 2017, 57.95 % (51/88) in 2018, 28.85 % (15/52) in 2019, and 45.68 % (37/81) in 2020. The high prevalence of serum antibodies to Leptospira among the stray dog population indicates that Mexicali provides optimal ecological conditions for maintaining and disseminating leptospire throughout the city, increasing the risk of infection to other domestic or companion animals and the human population. Further epidemiological research is necessary to identify the serovars in the region and propose strategies to control the stray dog population and the propagation of Leptospira in the Northwest region of Mexico.