The advancement of malaria control is significant; yet, the presence of drug-resistant malarial parasites remains an issue. In Pakistan, nearly one million malaria cases occur each year. A prospective, observational, cohort study was conducted among 354 malaria patients in Karachi, Pakistan. By Day 28, recurrent Plasmodium vivax infection occurred in 10/98 (10.2%) of participants receiving chloroquine (CQ) monotherapy, 17/84 (20.2%) receiving artemether–lumefantrine (AL) monotherapy, 1/93 (1.1%) receiving CQ plus primaquine (CQ + PQ), and 3/79 (3.8%) receiving AL plus primaquine (AL + PQ). The corresponding Kaplan–Meier cumulative incidence estimates at Day 28 were 13.4% (95% CI 5.6–21.2), 24.5% (95% CI 14.3–34.7), 1.5% (95% CI 0.0–4.4), and 5.3% (95% CI 0.0–11.2), respectively. By the end of six months of follow-up, observed recurrence was 15/98 (15.3%) for CQ, 27/84 (32.2%) for AL, 1/93 (1.1%) for CQ + PQ, and 5/79 (6.3%) for AL + PQ; Kaplan–Meier cumulative incidence estimates were 21.0% (95% CI 11.0–31.0), 39.1% (95% CI 26.7–51.4), 1.5% (95% CI 0.0–4.4), and 10.0% (95% CI 1.6–18.4), respectively. In unadjusted Cox proportional hazards models, AL monotherapy was associated with a higher hazard of recurrence than CQ monotherapy, while primaquine-containing regimens showed lower recurrence hazards than the corresponding monotherapies during follow-up.
Khan et al. (2026) studied this question.