A comparison between serological and molecular tests in diagnosis of Toxoplasma gondii infection among stray cats in Ahvaz, southwestern Iran

Abstract

<em>Toxoplasma gondii</em> infects all species of warm-blooded animals, including humans, and domestic cats and other felidae are its definitive hosts. The aim of the present survey was to compare serological and molecular tests in accurate diagnosis of <em>T. gondii</em> infection among stray cats in Ahvaz, Iran. A total of 100 cats were examined for the detection of serum antibodies against<em> T. gondii</em> (chronic phase) by enzyme-linked immunosorbent assay (ELISA) and modified agglutination test (MAT) and for the presence of antigen in the blood (active phase) by polymerase chain reaction (PCR). The studied cats were divided into seven age groups. According to the obtained results from ELISA, MAT, and PCR, the prevalence rates of <em>T. gondii </em>infection were 30%, 39%, and 8%, respectively. Kappa test showed that there was a good agreement between ELISA and MAT results (0.80), but it was obtained 0.24 for MAT and PCR and 0.34 for ELISA and PCR, indicating a fair agreement between them. The seroprevalence of this parasite was 53.33% and 48.71% in male cats and 46.66% and 51.28% in females based on ELISA and MAT, respectively. Gender did not significantly affect the prevalence of this infection (P>0.05), but there was a significant difference between age groups, with the highest rate belonging to cats aged less than three years (P<0.05). It can be concluded that the serologic tests such as ELISA and MAT have a good agreement in diagnosis of toxoplasmosis. Our findings showed that a considerable percentage of the cats were infected with chronic form of toxoplasmosis.