Course of serological tests in treated subjects with chronic Trypanosoma cruzi infection: a systematic review and meta-analysis of individual participant data.

OBJECTIVE: To determine the course of serological tests in subjects with chronic T. cruzi infection treated with antitrypanosomal drugs. METHODS: We conducted a systematic review and meta-analysis using individual participant data. Survival analysis and Cox proportional hazards regression model with a random effect to adjust for covariates were applied. The protocol was registered at www.crd.york.ac.uk/PROSPERO (CRD42012002162). RESULTS: We included 27 studies (1296 subjects) conducted in eight countries. The risk of bias was low for all domains in 17 studies (63.0%). We assessed 913 subjects (149 seroreversion events, 83.7% censored data) for ELISA, 670 subjects (134 events, 80.0% censored) for IIF, and 548 subjects (99 events, 82.0% censored) for IHA. A higher probability of seroreversion was observed in subjects aged 1-19 years compared to adults at a shorter time span. The chance of seroreversion also varied according to the country where the infection might have been acquired. For instance, the pooled adjusted hazard ratio between children/adolescents and adults for IIF test was 1.54 (95% CI 0.64-3.71) and 9.37 (3.44-25.50) in some countries of South America and Brazil, respectively. CONCLUSIONS: The disappearance of anti-T. cruzi antibodies was demonstrated along the follow-up. An interaction between age at treatment and country setting was shown.