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. (Med J Indones 2006; 15:251-8)