Abstract

Toxoplasmosis is a highly prevalent parasitic zoonosis caused by Toxoplasma gondii. It is rated the 4th most important food-borne disease by the Food and Agriculture Organization (FAO). Several diagnostic tests have been used in the detection of toxoplasmosis with varied level of reliability. Among the several diagnostic tests, polymerase chain reaction (PCR) is regarded as the most sensitive. Immunoperoxidase technique has also been used in the diagnosis of toxoplasmosis. This, however, has not been validated in the detection of Toxoplasma gondii in rats. We compared the results of the use of immunoperoxidase technique in the detection of Toxoplasma gondii in wild rats to ascertain the level of agreement with the use of PCR. Results of 75 samples previously tested by PCR for which immunoperoxidase technique was also used to test the presence of Toxoplasma gondii were computed for this study. The sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) were calculated. The use of immunoperoxidase technique in the diagnosis of toxoplasmosis was 84.6% sensitive and 50% specific. The ability of immunoperoxidase technique to detect a positive test for toxoplasmosis was 91.7%. With the high sensitivity and PPV, we conclude that immunoperoxidase technique can be used as a screening tool for Toxoplasma gondii with reliable results.

Key words: Toxoplasma gondii, polymerase chain reaction, immunohistochemistry, sensitivity, specificity