title: Posttherapeutic cure criteria in Chagas' disease: conventional serology followed by supplementary serological, parasitological, and molecular tests.
abstract: We performed a critical study of conventional serology, followed by supplementary serological, parasitological, and molecular tests, to assess the response to etiologic treatment of Chagas' disease. A group of 94 Chagas' disease patients treated with benznidazole at least 10 years earlier were evaluated from the laboratory and clinical points of view. When conventional serology (enzyme-linked immunosorbent assay [ELISA], indirect immunofluorescence [IIF], and indirect hemagglutination [IHA]) and classic criteria (consistent results with any two of the three tests) or more rigorous criteria (consistent results from the three tests) were used, 10.6% and 8.5% of patients were considered treated and cured (TC) by classic and rigorous criteria, respectively. Patients were then evaluated using supplementary (recombinant ELISA and Trypanosoma cruzi excreted-secreted antigen blotting [TESA-blot]), parasitological (hemoculture), and molecular (PCR) tests. The results of recombinant ELISA were similar to those with the rigorous criterion (three consistent test results). The TESA-blot group showed a higher percentage (21.3%) of negative results than the groups defined by either cure criterion. Hemoculture and PCR gave negative results for all treated and cured (TC) patients, regardless of the criterion used. Recombinant ELISA and TESA-blot tests showed negative results for 70% and 87.5% of the patients categorized as TC by the classic and three-test criteria, respectively. For patients with discordant conventional serology, the supplementary serological and molecular tests were the decisive factor in determining therapeutic failure. Clinical evaluation showed that 62.5% of TC patients presented with the indeterminate form of the disease. Additionally, treated patients with negative TESA-blot results should be reevaluated later with all methodologies used here to verify whether TESA-blot is a reliable way to determine early parasitological cure of Chagas' disease.
authors: Núcleo de Pesquisas em Ciências Biológicas (NUPEB), Instituto de Ciências Exatas e Biológicas (ICEB), Universidade Federal de Ouro Preto (UFOP), Ouro Preto, Brazil. girleyfrancisco@nupeb.ufop.br
authors: G F
authors: GF
authors: Machado-de-Assis
authors: A R
authors: AR
authors: Silva
authors: V A L
authors: VA
authors: Do Bem
authors: M T
authors: MT
authors: Bahia
authors: O A
authors: OA
authors: Martins-Filho
authors: J C P
authors: JC
authors: Dias
authors: P
authors: P
authors: Albajar-Viñas
authors: R M
authors: RM
authors: Torres
authors: M
authors: M
authors: Lana
mesh_terms: D000293:Adolescent; D000328:Adult; D000981:Antiprotozoal Agents / Q000008:administration & dosage; D014355:Chagas Disease / Q000175:diagnosis* / Q000188:drug therapy*; D002648:Child; D002675:Child, Preschool; D016903:Drug Monitoring / Q000379:methods*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D025202:Molecular Diagnostic Techniques / Q000379:methods*; D009593:Nitroimidazoles / Q000008:administration & dosage; D010274:Parasitology / Q000379:methods*; D012680:Sensitivity and Specificity; D012698:Serologic Tests / Q000379:methods; D014349:Trypanosoma cruzi / Q000276:immunology* / Q000302:isolation & purification*; D055815:Young Adult
chemical_list: D000981:Antiprotozoal Agents; D009593:Nitroimidazoles; C009999:benzonidazole