Seroreduction.
Optical density (OD) values measured by conventional ELISAs decreased over time in both treatment regimens during the study. At the 4-year posttreatment follow-up, the reduction in mean OD values from baseline was 23.72% and 18.68% by recombinant ELISA, and 23.81% and 19.08% by total purified antigen ELISA in the 60-day and 30-day treatment regimens, respectively. In Kaplan–Meier analyses that generated probability estimates for ≥20% to 100% seroreduction in OD values from baseline measured by two conventional ELISAs (recombinant ELISA and total purified antigen ELISA), a progressive reduction was seen in both treatment groups. At the 4-year follow-up, ≥20% to 100% seroreduction of around 50% and 40% was observed in the 60- and 30-day treatment regimen groups, respectively (Kaplan–Meier curves of ≥20% to 100% seroreduction in patients receiving 60-day or 30-day nifurtimox treatment regimens (full analysis set, Kaplan–Meier curves of ≥20% to 100% seroreduction by age in patients receiving (a) 60-day and (b) 30-day nifurtimox treatment regimens (full analysis set, 