Evaluation of Seropositivity of Toxoplasmosis Suspected Patients Admitted to the National Parasitology Reference Laboratory Between 2009 and 2019

Abstract
Toxoplasmosis caused by Toxoplasma gondii (T. gondii), which is an obligatory intracellular parasite, is a worldwide zoonotic parasitic disease. In this study, results of T. gondii test conducted between January 2009 and May 2019 were analysed. This study aimed to evaluate the results of T. gondii test of patients who were admitted to the General Directorate of Public Health, National Parasitology Reference Laboratory between 2009 and 2019. The results of anti-T. gondii IgG, IgM, IgG avidity and Sabin-Feldman dye tests (SFDT), which are used to detect the presence of T. gondii, were examined. ELISA was used for anti-T. gondii IgG, IgM and IgG avidity tests. SFDT, which is the reference test in the diagnosis of T. gondii, is still the gold standard. In addition to laboratory analyses, information on gender, age, city of origin, year distribution of all cases and type of sample sent was also collected. Of the 2.778 patients evaluated, 25.4% were males and 74.6% were females. Moreover, 47.1% and 10.2% of the patients were positive for anti-T. gondii IgG and anti-T. gondii IgM antibodies, respectively. In SFDT, 1.228 (52%) patients were found to be positive, including 319 (59.4%) of 537 men and 909 (49.8%) of 1.824 women. In this 10-year study, the most common seropositivity titre of SFDT was at the level of 1/64. In our study, IgG levels were found to be positive in all cases in which IgG avidity was studied when all the cases in which all three of the anti-T. gondii IgG, IgM and IgG avidity tests were studied together in one patient were evaluated. In addition, of the 293 patients with positive anti-T. gondii IgG, 62.8% had high avidity, 24.2% had a limit value and 13% had a low avidity. In cases involving both mother and baby, anti-T. gondii IgG and IgM seropositivity rates were 80% and 5% for both, respectively. These high rates support the transfer of antibodies from the mother to the baby. Regarding the distribution of provinces from which the samples originated, the highest number of cases came from Ankara (80.7%). Blood is the most predominant sample, followed by cerebrospinal fluid. T. gondii maintains its importance in public health, owing to its high positivity rates. This study, in which 10-year data were collected, showed that despite an increase in awareness, high seropositivity still continues. Therefore, systematic collection and evaluation of laboratory analysis results for toxoplasmosis diagnosis will contribute in taking control measures.