High Rates of Positive Hemocultures in Children and Teenagers Seropositive for Trypanosoma cruzi in the State of Rio Grande do Sul, Brazil

Combined parasitological and molecular-based diagnostic tools improve the detection of Trypanosoma cruzi in single peripheral blood samples from patients with Chagas disease

“…Interestingly, regardless of the clinical form, most cases were positive between 30 and 60 days, corroborating with previous data 4, 21,22,40 . BC may be wrongly considered positive due to in vitro production of motionless amastigotes for extended periods until the detection of moving forms, since a low number of amastigotes may be unnoticed 46,47 .…”

“…Despite these findings, we cannot rule out the possibility that BC variability may be directly related to the rate of T. cruzi infection in our specific patient group 22,39 . Higher positivity by BC has been shown in seroreactive patients between 4 and 20 years old when submitted to blood culture 40 . The period of cultivation also affects BC positivity; in previous studies, BC positivity was increased at 6 months after inoculation 41,21 .…”

Efficacy of benznidazol treatment for asymptomatic chagasic patients from state of Rio Grande do Sul evaluated during a three years follow-up

“…Luz et al (1993) found 90% positivity among untreated chronic chagasic patients from the state of Minas Gerais. Fernandes et al (1999) reported 76% positivity among children from the state of Rio Grande do Sul. Lower rates of sensitivity for chronic patients have been shown by other authors (Chiari et al 1989, 55.8%, Gomes et al 1999, 36.5%, Lages-Silva et al 2006.…”

Comparison of conventional serology and PCR methods for the routine diagnosis of Trypanosoma cruzi infection

“…In this study, hemoculture presented only 10.4% positivity, and the positivity rate is known to vary by geographical region and the stage of illness. While, Luz et al 20 observed 90% positivity in untreated chronic chagasic patients and Fernandes et al 21 observed 76% positivity among children infected with T. cruzi from the state of Rio Grande do Sul. Indeed, parasitological methods usually present low sensitivity during the chronic phase of Chagas disease 12,22,23 .…”