PCR in Blood Cultures of Individuals With Positive and Inconclusive Serology for Chagas' Disease

T. cruzi infection affects approximately five million people in Brazil. The diagnosis of the chronic phase of infection is performed by indirect serological methods which, nevertheless, leave inconclusive results. One of the direct methods used for T. cruzi identification, blood culture in LIT (liver infusion tryptose) medium, presents low sensitivity in that phase of the disease. A negative result does not eliminate the possibility of infection, but a positive test has high absolute diagnostic value, which enables the indication of antiparasitic treatment. Molecular diagnosis (PCR) in this phase is promising and can be used as a confirmatory test, particularly when individuals present inconclusive results in conventional serological tests, such as ELISA, HAI and IFI. This study aimed at improving blood culture sensitivity in LIT medium by performing PCR in individuals with positive and inconclusive serology for chagasic infection.