T. gondii Infection in Urban and Rural Areas in the Amazon: Where Is the Risk for Toxoplasmosis?

Toxoplasmosis, an infection caused by Toxoplasma gondii, which is found worldwide, can affect human and animal health in different ways. This study aimed to estimate the infection prevalence in humans and to determine risk factors related to urban and rural areas in a municipality in the Brazilian Amazon where an outbreak had been registered. Blood samples for serological analysis were obtained, and interviews were performed to fill out an epidemiological questionnaire. A total of 1140 individuals were included, of which 70.6% (804/1140; 95% CI: 67.9–73.2%) were positive for IgG anti-T. gondii antibodies. In rural areas, the prevalence was 62.6% (95% CI: 58.9–66.3%), while in urban areas, it was 81.9% (95% CI: 78.4–85.4%). The risk of becoming infected in urban areas was 2.7 times higher (95% CI = 2.0–3.6%) than that in rural areas. When comparing the prevalence in the age group from 1 to 10 years in both areas, the rate was 28.6% (42/147; 95% CI: 21.3–35.9%) for rural areas and 69.4% (61/88; CI 95%: 59.7–79.0%) for urban areas. Therefore, it is concluded that parasite exposure starts in the first years of life in urban areas and that disordered urban area expansion may cause an increase in exposure to the different strains of T. gondii present in the Amazon.