Detection of anti-Toxoplasma gondii antibodies in experimentally and naturally infected non-human primates by Indirect Fluorescence Assay (IFA) and indirect ELISA

The Indirect Fluorescence Assay (IFA) and the indirect ELISA were comparatively used to detect IgG and IgM antibodies for Toxoplasma gondii in experimentally and naturally infected primates In the experimentally infected group, antibodies of diagnostic value were detected at day 9 post-infection (PI) with the IFA (IgG and IgM) and with IgG-ELISA IgM-ELISA detected antibodies for T gondii starting at day 3 PI until the end of the experiment (102 days PI) Of the 209 naturally infected sera tested, from many loos of State of Sao Paulo, 64 59 and 67 94% were positive in the IgG-IFA test and IgG-ELISA respectively IgM-ELISA test detected seropositivity in 52 63% of the sera although IgM-IFA test detected it in only in 0 96% of the samples The differential toxoplasmosis diagnosis was accomplished with Neospora caninum by IFA, observing 61 (29 2%) seropositive animals for this parasite and 149 (70 8%) negative Sixty animals were positive for both T gondii and N caninum Pneumonia, splenomegaly, and intestinal ulcers were macroscopically observed Unremarkable interstitial pneumonia enteritis, colitis, splenitis, and glomerulitis were microscopically observed The immunohistochemical stain could not detect the presence of T gondii In the tissues of the animals infected experimentally