title: Blood culture and polymerase chain reaction for the diagnosis of the chronic phase of human infection with Trypanosoma cruzi.
abstract: In the present study, we evaluated for the first time the profile of blood parasitism in untreated, chronic Chagas' disease. The study was conducted on 60 patients and a control group of nine serologically negative individuals. Analysis of three blood samples showed 70% cumulative positivity for blood culture and 86.7% positivity for PCR. The comparison of the two tests revealed that 41.1% (74/180) of the samples presented positive results for both PCR and blood culture, 22.2% (40/180) were positive for PCR alone, and 4.4% (8/180) were positive for blood culture and negative for PCR. The addition of the second sample raised positivity significantly for both blood culture ( P=0.0000) and PCR ( P=0.0369). Addition of the third sample was also statistically significant for blood culture ( P=0.0001) but not for PCR ( P=0.1186). These data point to the importance of studying the parasitemia of Trypanosoma cruzi-infected individuals before specific treatment. They also suggest that at least two blood samples should be collected and that two tests should be used, if possible--a procedure that considerably improves the parasitologic diagnosis of Chagas' disease and the evaluation of therapeutic efficacy.
authors.affiliation: Departamento de Microbiologia, Imunologia, Parasitologia e Patologia, Instituto de Patologia Tropical e Saúde Pública--Universidade Federal de Goiás, Goiânia GO, Brazil.
authors.forename: A M
authors.initials: AM
authors.lastname: Castro
authors.forename: A O
authors.initials: AO
authors.lastname: Luquetti
authors.forename: A
authors.initials: A
authors.lastname: Rassi
authors.forename: G G
authors.initials: GG
authors.lastname: Rassi
authors.forename: E
authors.initials: E
authors.lastname: Chiari
authors.forename: L M C
authors.initials: LM
authors.lastname: Galvão
mesh_terms: D000818:Animals; D018929:Cell Culture Techniques / Q000379:methods*; D014355:Chagas Disease / Q000175:diagnosis*; D002908:Chronic Disease; D015342:DNA Probes; D006801:Humans; D018512:Parasitemia / Q000175:diagnosis*; D021261:Parasitic Sensitivity Tests; D016133:Polymerase Chain Reaction / Q000379:methods*; D014349:Trypanosoma cruzi / Q000472:pathogenicity
chemical_list: D015342:DNA Probes