Sero-molecular evaluation of Toxoplasma gondii in patients with coronavirus in patients referred to health laboratories of Tabriz city

Abstract

Co-infection of SARS-CoV-2 with toxoplasmosis among people with covid-19 disease is an emerging concern worldwide. In this case-control study, the possible association between SARS-CoV-2 and Toxoplasma gondii infection was evaluated using serological and molecular methods. Methods: Seventy people with SARS-CoV-2 who were positive by RT-PCR molecular diagnosis method from June to September 1400, who had visited the Jame Salamat Laboratory in the northwest of Iran, in the city of Tabriz, were included in the study. Seventy healthy people with age and gender distribution according to people with covid-19 disease were included in the study by group matching method. Blood samples were taken from all participants in the study and serums were screened for anti-toxoplasma antibodies (IgG and IgM). Nested-PCR method was performed for B1 gene and single round PCR for GRA6 gene of Toxoplasma gondii. The PCR products were sent directly to perform phylogenetic analysis for sequencing. Results: The seroprevalence of toxoplasmosis based on IgG titer was 35.7% in the COVID‑19 patients and 27.1% in the control group, representing not to be associated with the Toxoplasma seropositivity in COVID‑19 patients (P= 0.18) compared to healthy subjects. Anti-T.gondii IgM was not found in any of the patients and healthy individuals. According to PCR amplification of the B1 and GRA6 genes, the frequency of T. gondii in COVID-19 patients was 10% (7/70). However, no T. gondii infection was detected in the healthy group. The CD4+T cell count was relatively lower in toxoplasmosis-infected patients (430–450 cells/mm3) than in control group (500–1500 cells/mm3). High genetic diversity (Hd: 0.710) of the type I strain of T. gondii was characterized in the patients. Present results showed that consumption of raw vegetables and close contact with stray cats can increase the transmission of T. gondii to COVID-19 patients (P< 0.01).