Serosurveillance of pathogenic Leptospira in ruminants from a veterinary teaching hospital

Leptospirosis can affect livestock health and production, potentially causing abortion, stillbirth, and infertility. An endemic presentation of infection in ruminants most likely occurs in southern Chile. A pilot study was conducted in a veterinary hospital in Puerto Montt to perform epidemiological surveillance to determine the seropositivity of pathogenic Leptospira in different ruminant species using a microscopic agglutination test (panel of eight serogroups) and to identify the most common serogroups and antibody titers in seropositive animals. Serum samples were collected from 43 ruminants (20 cattle, 18 sheep, 4 goats, and 1 alpaca). The overall seropositivity was 69.7% (95% confidence interval (CI) = 56.0–83.4), which is the highest rate reported so far in ruminants in the country. Elevated seropositivity was recorded in cattle (85.0%; 95% CI = 69.3%–100%), followed by sheep (66.7%; 95% CI = 45.0%–87.0%) and goats (25.0%; 95% CI = 0%–67.4%). The predominant serogroups were Tarassovi and Sejroe, followed by Autumnalis and Canicola, with different antibody titers according to the serogroup. It is recommended to consider the implementation of epidemiological surveillance for pathogenic Leptospira in different settings, such as other veterinary hospitals and farms, to elucidate the reproductive and economic consequences that the disease may cause in different ruminant species, and to apply preventive measures due to the zoonotic potential of the bacterium.