Seroprevalence of Toxoplasma gondii among animal-associated workers and companion animals in South Korea

Toxoplasma gondii is a widely distributed zoonotic parasite at the human–animal interface. However, studies simultaneously evaluating animal-associated workers and companion animals remain limited in South Korea. This multi-regional cross-sectional study aimed to estimate the apparent seroprevalence of T. gondii and explore associated factors among selected animal-associated workers, shelter animals, and companion animals. A total of 259 human participants and 1259 animals were enrolled. Structured questionnaires were used to assess occupational and behavioral risk factors, and serum samples were tested using commercial ELISA kits. The apparent seroprevalence was 15.1% (95% CI 11.2–19.9) in humans, 20.6% (95% CI 12.5–32.2) in animal shelter workers, and 13.3% (95% CI 9.2–18.7) in livestock disease control workers; the difference between the occupational groups was not statistically significant. Seroprevalence increased significantly with age ( p = 0.0003). A history of dog bites or dog-related injuries outside the workplace was independently associated with seropositivity (adjusted OR, 6.54; 95% CI 1.11–38.48; p = 0.04). The apparent seroprevalence was 14.1% (95% CI 11.5–17.3) in shelter dogs, 16.3% (95% CI 13.2–20.0) in companion dogs, 3.0% (95% CI 0.5–15.3) in shelter cats, and 3.2% (95% CI 1.6–6.4) in companion cats. Because the participants and animals were selected non-randomly, the findings should not be generalized to the overall human or animal populations of South Korea. These results support continued monitoring and targeted risk-awareness and preventive education for animal-associated occupational groups.