Efficacy of existing antimalarial drugs for uncomplicated malaria in Timika, Papua, Indonesia

Chloroquine resistant malaria is a serious problem in Indonesia particularly in Papua. A trial of the existing antimalarial drugs was conducted in Timika, Papua. The objective of the study was to determine the efficacy of cloroquine (CQ) + sulfadoxine-pyrimethamine (SP). Patients with uncomplicated malaria due to Plasmodium falciparum, P. vivax, P. ovale or P. malariae were enrolled and treated with supervised CQ+SP (P. falciparum) or CQ (non-P. falciparum). Patients were followed for 28-42 days. Patients failing therapy were retreated with unsupervised quinine±doxycycline. 207 patients were enrolled in the study (88 P. falciparum, 40 P. vivax, 15 mixed infections, 50 P. malariae and 14 P. ovale). Early treatment failures occurred in 4 of 86 (5%) patients with falciparum malaria, 6 of 37 (16%) patients with vivax malaria and none of those with P. ovale or P. malariae infections. The failure rate by day 28 for P. vivax was 22 of 30 (73%) patients, with all recurrences occurring in the presence of plasma chloroquine concentration above the minimum effective concentration (MEC>15ng/ml). After correcting for reinfections the day 42 recrudescence rate for falciparum malaria was 48% [95%CI:31-65] and in 61% of cases this was in the presence of chloroquine levels above 30 ng/ml. Retreatment with unsupervised quinine±doxycycline resulted in further recurrence of malaria in 48% [95%CI:31-65] of P. falciparum infections and 70% [95%CI:37-100] of P. vivax infections. None of the patients with P. ovale or P. malariae had treatment failures within 28 days. There is a high prevalence of antimalarial drug resistance of P. falciparum and P. vivax to the existing antimalarial drugs. However chloroquine retains adequate efficacy against P. ovale and P. malariae in Papua