Human Toxoplasma gondii Seroprevalence in the Canary Islands: Implications for One Health Surveillance and Control

Toxoplasma gondii is a globally significant foodborne parasite, yet epidemiological data in Spain are limited. This study provides the first comprehensive assessment of human T. gondii seroprevalence across the Canary Islands and identifies key risk factors. A total of 1223 serum samples were tested for anti-T. gondii IgG antibodies using ELISA. Demographic and geographic data were recorded. Overall seroprevalence was 32.3%, with no significant differences between sexes. Geographic variation was notable: the highest seroprevalence occurred in the western islands (La Palma 52.4%) and the lowest in the eastern islands (Gran Canaria 17.6%). Seropositivity increased progressively with age, ranging from 0% in children (0-15 years) to 51.3% in individuals over 60 years. Climatic factors also influenced exposure, with the temperate cold isoclimate associated with higher seroprevalence and arid zones showing more seronegative cases. Logistic regression confirmed age and isoclimate as significant predictors of seropositivity. The observed decline in prevalence compared to historical data suggests improvements in hygiene, dietary practices, and public health measures. Nevertheless, moderate-to-high risk persists, particularly among older adults and in favourable environmental conditions. These findings underscore the importance for One Health strategies, i.e., food safety and education, feral cat control and human and animal surveillance.