Seroepidemiology of infection with Toxoplasma gondii in migrant agricultural workers living in poverty in Durango, Mexico

Cosme Alvarado-Esquivel, Federico Campillo-Ruiz, Oliver Liesenfeld

BACKGROUND: Migrant agricultural workers are a group of people living in poverty with poor housing, sanitary conditions and hygiene practices. Little is known about the epidemiology of infection with Toxoplasma gondii in migrant agricultural workers. METHODS: We investigated the presence of anti-Toxoplasma IgG and IgM antibodies in 173 migrant workers hired for seasonal agricultural work in Durango State in northern Mexico using enzyme-linked immunoassays. RESULTS: Of the 173 migrant workers (mean age 34.82 +/- 14.01 years), 50 (28.9%) had anti-Toxoplasma IgG antibodies and 36 (20.8%) had anti-Toxoplasma IgM antibodies. Seroprevalence was not influenced by gender, age, birth place, or educational level. In contrast, seroprevalence was significantly higher in workers residing in rural areas than those in urban or suburban areas. Migrant workers suffering from memory impairment, dizziness, or syncope had significantly higher seroprevalence of anti-T. gondii IgG antibodies than those without such clinical features. Logistic regression analysis showed that T. gondii exposure was positively associated with consumption of unwashed raw vegetables (OR = 2.39; 95% CI: 1.06-5.35; P = 0.03) and low frequency of eating out of home (OR = 3.87; 95% CI: 1.43-10.42; P = 0.007), and negatively associated with national trips (OR = 0.30; 95% CI: 0.13-0.65; P = 0.003) and consumption of raw milk (OR = 0.40; 95% CI: 0.18-0.87; P = 0.02). Other behavioral characteristics including consumption of meat or untreated water were not associated with T. gondii infection. CONCLUSIONS: This is the first report of T. gondii infection in internal migrant agricultural workers living in poverty. Results deserve further investigation of causal relations between clinical symptoms and infection, and may be useful for optimal planning of preventive measures.