First serological and molecular detection of Toxoplasma gondii in guinea pigs (Cavia porcellus) used for human consumption in Nariño, Colombia, South America.

Consumption of undercooked meat is one of the main transmission routes for Toxoplasma gondii worldwide. In the South American Andes, the guinea pig (Cavia porcellus) is a domestic rodent representing one of the main sources of animal proteins for indigenous communities. Although T. gondii infects a wide range of rodents worldwide, the natural impact of the infection on guinea pig populations is still unknown. Our study conducted in guinea pigs that were bred in traditional systems located in the village of José María Hernández (Nariño, Colombia) revealed the presence of T. gondii antibodies in 33.3% (23 out of 69) guinea pigs evaluated, with a cut-off point of 25 for the modified direct agglutination test. Conventional PCR detection of the T. gondii-specific RE fragment (529 bp) in 207 collected tissues demonstrated the presence of T. gondii DNA in several organs, including the brain (16/69), muscle (12/69), and heart (4/69), with an overall molecular detection frequency of 27.5% (19 out of 69 guinea pigs). This is the first report of natural infection of guinea pigs with T. gondii, demonstrating their potential epidemiological role in transmitting the infection to autochthonous populations.

Seroprevalence of Toxoplasma gondii antibodies from wild canids from Brazil.

The prevalence of anti-Toxoplasma gondii antibodies was evaluated by the indirect immunofluorescent-antibody test in serum of 57 wild canids from three different species: Lycalopex gymnocercus, Cerdocyon thous and Dusicyon vetulus from the northeast, southeast and southern regions of Brazil. The prevalence was 35.1%, with 20 of the 57 canids demonstrating antibodies anti-T. gondii at dilutions of 1:16 in 2, 1:32 in 4, 1:64 in 2, 1:128 in 2, 1:256 in 6, 1:512 in 2 and 1:2048 in 2 animals. None of the D. vetulus were positive. Among the L. gymnocercus 11 (91.7%) of the 12 samples were positive and among C. thous 9 (60%) of the 15 had antibodies anti-T. gondii.