Technical evaluation of serological screening tests for anti-Toxoplasma gondii antibodies to prevent unnecessary transfusion risks

Serological assays to detect anti-Toxoplasma gondii antibodies and specific anamnesis associated with this highly prevalent infection could be necessary in hemotherapy services in order to regulate safer blood supplies thus avoiding unnecessary transfusion risks. Even though, such policies are not yet implemented. In order to evaluate this requirement, our research group designed a questionnaire filled up by 132 volunteer blood donors from Parana Hemotherapy Center (Hemepar) assessing the possible risk factors to toxoplasmic infection. A total of 20 IgG anti-Toxoplasma serological tests were done to check out for positive-reactivity. 60% of the selected serum samples reacted positively; from these, 50% reported having pets (average of 2 animals per person) and 33% of these pets were "semi-free". It suggested the probability of toxoplasmic infection through these animals. Only 2.2% of the interviewed individuals were aware of the correct concept of the disease and only 17% of them were actually approached by the Blood Center concerning the epidemiological importance of this disease. The current procedures established during blood transfusions are not entirely safe when associated to toxoplasmosis. Today there are no rules that standardize a seroscreening protocol, nor preventive measures for this disease related to hemotherapy services in Brazil, as well as in other services worldwide.