T. gondii is a life-threatening infection in immunocompromised patients which may be transmitted through blood transfusion. The present study aimed to evaluate the seroprevalence and molecular detection of T. gondii infection and the associated risk factors among young healthy blood donors in the central part of Mazandaran province, northern Iran. Blood samples were taken from 500 participants and the serum was separated. All serum samples were tested for the presence of anti-T. gondii antibodies (IgG) and then all positive samples were evaluated for IgM antibodies using commercial ELISA kits. All IgM positive samples and 66 randomly selected IgG positive samples were further tested by PCR of the REP-529 gene. Anti-Toxoplasma antibodies (IgG) avidity test was performed for 142 IgG positive samples which were randomly selected. In the current study, anti-T. gondii antibodies (IgG) and (IgM) were found in 316 (63.2%) and 3 (0.95 %) participants, respectively. Seropositivity rate of Toxoplasma was higher among blood donors living in rural areas (P=0.000) and those with a history of soil and animal contact (P<0.05). PCR of the REP-529 gene showed T. gondii DNA in 21 out of 66 samples. The REP-529 gene was not detected in IgM positive samples. Low avidity antibodies (IgG) was found in 23.2% of the IgG positive samples. In conclusions, this study found that the prevalence of toxoplasmosis among young healthy blood donors in north of Iran was high. To reduce the risk of parasite transmission, leukofilteration method are recommended for donated blood used for immunosuppressed patients.
Strongyloides stercoralis is a parasite that causes strongyloidiasis worldwide. It may lead to a life-long infection in immunocompetent people and hyperinfection in immunosuppressed patients. A point-of-care (POC) rapid test is helpful for patient diagnosis in resource-limited settings and as a detection tool in elimination/control programs. Previously, we reported a rapid IgG4 dipstick test (Ss Rapid®) for Strongyloides suitable for a laboratory setting. A POC cassette format of the test, which is field-applicable, has since been developed. Here, we report on a laboratory-based evaluation of the Ss Rapid® cas sette test on 285 sera. We assessed the diagnostic sensitivity of the Ss Rapid® cas sette with 32 sera, comprising samples from larval and/or DNA positive individuals from three countries. Additionally, we also tested samples from 33 seropositive endemic areas residents. We evaluated the diagnostic specificity of the test using 220 samples, comprising sera from other infections (n = 101), allergy cases with high IgE antibodies (n = 4), and blood donors (n = 115). The test showed high diagnostic sensitivity (97%, 31/32), and all sera of the seropositive endemic residents were reactive. It also showed high diagnostic specificity (94.5%, 208/220), and all false-positive samples tested negative after sera adsorption using recombinant NIE-coated microsphere beads. Additionally, we showed that the test worked with spiked whole blood samples. The study results showed that the SsRapid® cas sette test merits further laboratory and field evaluations.