Seroepidemiology of Toxoplasma gondii Infection in Tepehuanos in Durango, Mexico

The epidemiology of Toxoplasma gondii infection is known to depend on a number of behavioral factors, including contact with animals and eating habits. The epidemiology in specific populations (i.e., in indigenous ethnic groups) is not well studied. We therefore investigated the presence of anti-Toxoplasma IgG and IgM antibodies in 156 Tepehuanos, an indigenous ethnic group in Durango State in northern Mexico, using ELISAs. Of the 156 Tepehuanos (mean age 31.03 +/- 16.71 years), 35 (22.4%) had anti-Toxoplasma IgG antibodies. IgG levels of 14-99, 100-150, and > 150 IU/mL were found in 15 (42.9%), 1 (2.8%), and 19 (54.3%) anti-Toxoplasma IgG-positive Tepehuanos, respectively. Also, 15 (9.6%) subjects had anti-Toxoplasma IgM antibodies. Male Tepehuanos aged 31-50 years showed a significantly higher frequency of exposure to T. gondii than female Tepehuanos of the same age. Seroprevalence of anti-T. gondii IgM antibodies was significantly higher in Tepehuanos without education than those with 7-12 years of education. Tepehuanos suffering from frequent headaches had significantly higher seroprevalences of anti-T. gondii IgG and IgM antibodies than those without this clinical feature. In addition, Tepehuanos suffering from hearing impairment had significantly higher seroprevalence of anti-T. gondii IgM antibodies than those without this clinical feature. Logistic regression analysis did not show an association of T. gondii exposure with any behavioral characteristics, including contact with cats or eating habits. The seroprevalence of T. gondii exposure in Tepehuanos is comparable to that reported in other populations in North America; however, seroprevalence in the largely rural Tepehuanos is higher than that reported in a nearby urban center. Toxoplasma may be impacting the health of Tepehuanos. This is the first report of T. gondii infection in Tepehuanos, and the results should prove useful for the design of preventive measures.