Use of filter papers to determine seroprevalence of Toxoplasma gondii among hunted ungulates in remote Peruvian Amazon

Abstract

Toxoplasmosis is a zoonosis caused by the protozoan Toxoplasma gondii, and it is found worldwide. To determine whether ungulates are reservoirs of T. gondii in an isolated and remote region of the northeastern Peruvian Amazon, antibodies to T. gondii were determined in 5 species of ungulates by the modified agglutination test (MAT). These animals were hunted by subsistence hunters along the Yavarí-Mirín River, in the northeastern Peruvian Amazon. Blood samples were collected by hunters on filter papers. For determination of T. gondii antibodies, blood was eluted from filter papers, and a titer of 1:25 was considered indicative of exposure to T. gondii. Antibodies to T. gondii were found in 26 (31.0%) peccaries (Pecari tajacu, Tayassu pecari), six (17.1%) brocket deer (Mazama americana, Mazama gouazoubira), and four (40.0%) lowland tapir (Tapirus terrestris). We also introduced a modification to the MAT protocol that allows the extraction of fluid samples from several types of laboratory-grade filter paper, thus enabling researchers to easily adapt their approaches to the materials presented to them.

Keywords: Brocket deer (Mazama americana, Mazama gouazoubira); Filter paper; Lowland tapir (Tapirus terrestris); Modified agglutination test; Peccary (Pecari tajacu, Tayassu pecari); Toxoplasma gondii.

Graphical abstract

Fig. 1

Animals were hunted in the area surrounding the community of Nueva Esperanza, the only permanent settlement located along the Yavarí-Mirín River. The study site’s geographic remoteness reflects extremely limited contact with domestic animals and humans, which eliminates the effect of spillover from domestic animals as a potential source of infection for wildlife. The data from this study are likely to shed light on the maintenance of T. gondii in its natural environment.