Serosurvey on Toxoplasmosis in Outdoor Pig Production Systems of the Southern Region of Brazil

Pigs out to pasture on a large scale is a fairly new occurrence in Brazil, but it represents an area of growing interest. Antibodies to Toxoplasma gondii were found in 86.08% of 115 pigs. According to the modified agglutination test, the following antibody titers were found: 1:50 (3.47%), 1:100 (6.08%), 1:200 (9.56%), 1:400 (6.95%), 1:800 (6.95%), 1:1600 (6.95%) and 1:3200 (55.65%). The environment fecal contamination by cats or by consumption of infected rodents is probably the most significant source of toxoplasmosis in outdoor-reared pigs. The economic toxoplasmosis impact of outdoor pig production systems, as well as its public health importance, should be assessed. The present results suggest that toxoplasmosis is common in pigs reared outdoors in the region. Health authorities should increase their monitoring and control activities in order to decrease the risk of toxoplasmic infections, especially among pregnant women. This is the first report on T. gondii infection in pigs reared according to the outdoor pig production system in Brazil.