Aetiological treatment of congenital Chagas' disease diagnosed and monitored by the polymerase chain reaction

SCHIJMAN AG; ALTCHEH J; BURGOS JM; BIANCARDI M; BISIO M; LEVIN MJ; FREILIJ H

JOURNAL OF ANTIMICROBIAL CHEMOTHERAPY

OXFORD UNIV PRESS

Lugar: Oxford; Año: 2003 vol. 52 p. 441 - 449

0305-7453

This prospective study focused on the evaluation of anti-parasitictherapy in congenital Chagas' disease, diagnosed and monitored by PCR andconventional diagnosis.MATERIALS AND METHODS: We studied 152 children born to seroreactive mothers,living in a non-endemic area. Fifty infants aged 0-6 months (GA) were diagnosedby microhaematocrit and PCR and 102 children aged 7 months to 17 years (GB) were diagnosed by serology and PCR. Forty treated patients were monitored for 2 or 3years by PCR and conventional methods. A competitive-quantitative PCR was used todetermine pre-therapy parasitic loads and follow their post-treatment evolution.RESULTS: In GA, the sensitivities of the PCR and microhaematocrit were 100% and82.4% and their specificities 97% and 100%, respectively. In GB, the sensitivity of the PCR was 73.8% with a specificity of 100%. Pre-therapy parasitic loadsranged from 12.5 to 125,000 and 12.5 to 125 parasite genomic equivalents/mL ofblood in GA and GB, respectively. PCR turned negative in all treated pre-therapy PCR positive patients before or at the end of treatment, which was followed bytheir seronegativation in 10/10 GA, in 3/5 children initiating therapy at 7months to 2 years of age but in 0/16 initiating therapy at an older age. Two out of the latter patients were occasionally PCR positive during post-treatment,suggesting no parasitological response. Out of nine pre-therapy PCR negativepatients, four turned seronegative after treatment, suggesting that inundetermined patients, undetectable parasitic burdens may lead to betterpost-treatment prognosis.CONCLUSIONS: PCR was useful for sensitive diagnosis and therapy monitoring,allowing early detection of refractory cases.