Prevalence of Toxoplasma gondii Infection among Healthy Blood Donors in Northeast of Iran

Background: This cross-sectional investigation aimed to evaluate the prevalence of IgM and IgG anti-Toxoplasma gondii antibodies and the associated risk factors among healthy blood donors in Khorasan Razavi Province, northeast of Iran from Nov 2014 to May 2015. Methods: Overall, 491 serum samples from apparently healthy blood donors referred the six biggest blood centers in Razavi Khorasan, Iran, were screened for IgG and IgM anti-T. gondii antibodies by enzyme-linked immunosorbent assay (ELISA). A structured questionnaire was used to obtain information on risk factors for T. gondii infection. Nested PCR was also used to detect DNA of T. gondii in the IgM-positive samples by using of B1 and RE (Repetitive Element) as marker for amplifying fragment size of 531 bp and 164 bp in PCR method. Results: Totally, 200 (40.7%) samples were seropositive for anti-T. gondii antibodies; 184 ( 37.5%) donors tested seropositive for only IgG antibody, 8 (1.6%) tested seropositive for both IgM and IgG and 8 ( 1.6%) were positive for IgM antibody alone. Several risk factors significantly related to T. gondii seropositivity in the univariate analysis at P<0.05 included age (P<0.001), and raw/half-cocked meat consumption (P=0.015). T. gondii DNA was found in all sixteen IgM-positive samples. Conclusion: T. gondii infection was present among healthy blood donors in northeast of Iran. Thus, it is suggested to design screening programs for preventing transfusion-transmitted toxoplasmosis.