Socioeconomic vulnerability associated with toxocariasis exposure in southern Brazil: a One Health approach

Although toxocariasis has been listed among the five most neglected parasitic infections worldwide, with higher impact in socioeconomically vulnerable populations, no study has evaluated vulnerable individuals from highly populated urban areas.

Accordingly, human serum samples were collected in Curitiba, the eighth most populated metropolitan area of Brazil, and tested by indirect enzyme-linked immunosorbent assay (ELISA) for anti-Toxocara spp. antibodies. Sociodemographic and environmental information was collected by epidemiological questionnaires and geospatial data to assess associated risk factors and toxocariasis areas.

Overall, 58 of 132 (43.9%) (95% CI: 35.8-52.5%) human samples were seropositive for Toxocara spp., with the final multivariate logistic regression model identifying age as the only predictive factor associated with seropositivity. Individuals aged 53 to 80 years had a 3.46 times higher risk (OR = 3.46; 95% CI: 1.24-10.17; p < 0.05) when compared to the 3 to 20 years group. Kernel analysis revealed an area with a higher density of seropositive individuals in locations lacking access to basic sanitation, highlighting a spatial risk area for Toxocara spp. transmission.

Although age over 53 years was the only predictor in the final logistic regression model, the spatial overlap between asymptomatic seropositive individuals and areas of high environmental vulnerability-marked by low income, flooding, and poor sanitation-was critical. These conditions likely facilitated the Toxocara spp. life cycle, making the identification of such areas pivotal for local public health, effectively targeting toxocariasis intervention and control strategies. In addition, the One Health approach herein highlights human vulnerability to toxocariasis as a life-course risk, beyond pet healthcare and environmental exposure in endemic areas.