Seroprevalence and Toxoplasma gondii-IgG avidity in sheep from Lajes, Brazil.

Sheep are important domestic animals in the Northeast region of Brazil due to their minimal rearing and maintenance costs, and to their production of both meat and milk. In animals, Toxoplasma gondii infection results in significant reproductive and economic losses. The epidemiology of toxoplasmosis in sheep in the Northeast of Brazil has been little studied; particularly in Rio Grande do Norte State. Sera from 102 sheep intended for consumption in Lajes were subjected to the Toxoplasma-ELISA test to detect anti-T. gondii specific IgG confirming a past infection. Of the total tested, 30 (29.41%) sera were positive for IgG with an increasing number of positive animals with advancing age. We used IgG avidity ELISA in 30 positive samples and observed that 6 (20%) had low avidity antibodies and 24 (80%) had high avidity antibodies. Epidemiological studies are required in order to identify sources of infection for these hosts as well as their impact on animal breeding in the region and risk of transmission to humans.