ARS | Publication request: Seroprevalence of Toxoplasma gondii infection in domestic pigs in Durango State, Mexico

Submitted to: Journal of Parasitology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: March 1, 2011
Publication Date: August 1, 2011
Citation: Alvarado-Esquivel, C., Garcia-Machado, C., Alvarado-Esquivel, D., Gonzalez-Salazar, A.M., Briones-Fraire, C., Vitela-Corrales, J., Villena, I., Dubey, J.P. 2011. Seroprevalence of Toxoplasma gondii infection in domestic pigs in Durango State, Mexico. Journal of Parasitology. 97:616-619.

Interpretive Summary: Toxoplasma gondii is a single-celled parasite of all warm-blooded hosts worldwide. It causes mental retardation and loss of vision in children, and abortion in livestock. Cats are the main reservoir of T. gondii because they are the only hosts that can excrete the resistant stage (oocyst) of the parasite in the feces. Humans become infected by eating undercooked meat from infected animals and food and water contaminated with oocysts. In the present study, authors report prevalence of Toxoplasma in pigs destined for human consumption in Mexico. The results will be of interest to biologists, parasitologists, and public health workers.

Technical Abstract: Little is known concerning the prevalence of Toxoplasma gondii infection in pigs in Mexico. Antibodies to T. gondii were determined in 1,077 domestic pigs in Durango, Mexico using the modified agglutination test (MAT). Two groups (A, B) of pigs were sampled: Group A pigs (n=555) were raised in 3 geographical regions in Durango State and Group B pigs (n=522) were from Sonora State but slaughtered in Durango City. Overall, antibodies to T. gondii were found in 137 (12.7%) of 1,077 pigs, with titers of 1:25 in 30, 1:50 in 23, 1:100 in 18, 1:200 in 22, 1:400 in 12, 1:800 in 8, 1:1,600 in 2, and 1:3,200 or higher in 22. Of the pigs raised in Durango State, seroprevalence varied with age, management, and the geographic region; pigs raised in backyards in the mountainous region had a significantly higher seroprevalence (32.1%) than those raised at the valley region (13%) and the semi-desert region (14%). Seroprevalence was lower in younger (<9 mo-old) pigs (10.9%) than older (19.5%) pigs. A significantly higher seroprevalence was observed in pigs raised in Durango State (Group A, 16%) than those from Sonora State (Group B, 9.2%). Toxoplasma gondii infection was higher in mixed breed (15.7%) than in pure bred (10.4%) pigs. This is the first in depth study on the seroprevalence of T. gondii infection of pigs in Mexico, and the first report in pigs from Durango State, Mexico. Results indicate that infected pork is likely an important source of T. gondii infection in humans in Durango State.