Good efficacy of artemether-lumefantrine for uncomplicated falciparum malaria in eastern Sumba, East Nusatenggara, Indonesia

AIM

to evaluate the safety and efficacy of a fixed combination of artemether-lumefantrine for likely use against failures of the artesunate-amodiaquine first line therapy.

METHODS

the study was an open label single arm uncontrolled trial. we evaluated the safety and efficacy of standard artemether-lumefantrine therapy in 59 subjects with uncomplicated malaria caused by Plasmodium falciparum on the island of Sumba in eastern Indonesia. No treatment failures occurred up to day 35. One subject had recurrent parasitemia on day 42 that showed a genotype consistent with recrudescence. The efficacy of this therapy was thus estimated to be 98.3% (95% confidence interval=95%-100%). Descriptive analysis was done using the SPSS 12 computer software.

RESULTS

two hundred and thirteen P. falciparum patients met the inclusion criteria for in vivo efficacy study, 79 were given artemether-lumefantrine and 134 were treated under another protocol with artesunate-amodiaquine or sulfadoxine-pyrimethamine. Among 79 eligible subjects, 59 successfully completed the 42-day test. As expected, the mean PCT was longer than the mean FCT, i.e. 1.34 ± 0.67 (95% CI 1.21-1.47) and 1.05 ± 0.05 (95% CI 0.95-1.15) days, respectively. On day 3 of treatment, both fever and asexual stage of P. falciparum disappeared in all subjects. Observation until Day 35 showed that all of the 59 subjects treated with artemether-lumefantrine were cured.

CONCLUSION

the findings of this uncontrolled study suggest good safety and efficacy of artemether-lumefantrine for treatment of uncomplicated falciparum malaria on Sumba Island in the Lesser Sundas archipelago of eastern Indonesia.

Real-time PCR for dihydrofolate reductase gene single-nucleotide polymorphisms in Plasmodium vivax isolates

Mutations in the dhfr gene of Plasmodium vivax (pvdhfr) are associated with resistance to the antifolate antimalarial drugs. Polymorphisms in the pvdhfr gene were assessed by hybridization probe technology on the LightCycler instrument with 134 P. vivax-infected blood samples from Turkey (n = 24), Azerbaijan (n = 39), Thailand (n = 16), Indonesia (n = 53), and travelers (n = 19). Double mutations (S58R and S117N) or quadruple mutations (F57L/I, S58R, T61M, and S117N) in the pvdhfr genes were found in all Thai samples (100%). pvdhfr mutant-type alleles were significantly more common in samples from travelers (42%) than in those from patients from Indonesia (5%). Surprisingly, the pvdhfr single-mutation allele (S117N) was identified at a high frequency in parasites from Turkey and Azerbaijan (71 and 36%, respectively), where sulfadoxine-pyrimethamine is not recommended for the treatment of P. vivax malaria by the World Health Organization and the Malaria National Programs.

Comparative efficacy of chloroquine and sulfadoxine-pyrimethamine for uncomplicated Plasmodium falciparum malaria and impact on gametocyte carriage rates in the East Nusatenggara province of Indonesia

The efficacy of chloroquine (CQ) and sulfadoxine-pyrimethamine (SP) was evaluated in 89 subjects greater than one year of age with uncomplicated P. falciparum malaria in the East Nusatenggara Province of Indonesia. Fever clearance time was longer in the SP group than in the CQ group. However, parasite clearance time was extended in subjects who received CQ compared with those who received SP. Major adverse events were not observed in either group, and no hospitalizations were required during the study. Treatment failure rates at day 28 were 69% for CQ and 8.5% for SP. In both treatment groups, gametocytemia developed during the follow-up period, but was more pronounced in the SP group, peaking at 94% on day 7. Regardless of treatment group, children < 10 years of age had significantly higher treatment failure rates than subjects >/=10 years of age (relative risk = 2.49), suggesting that acquired immunity influenced treatment outcomes in the presence of parasite drug resistance. Although a highly effective alternative to CQ for clearing infection, SP treatment also presented some potential drawbacks (e.g., increased and persistent gametocytemia). Replacement of CQ with SP as a first-line therapy, either alone or in combination with CQ, in those areas of Indonesia with high levels of CQ resistance should significantly improve treatment outcomes, particularly in vulnerable populations lacking clinical immunity. More efficacious and rapidly acting asexual stage treatments are generally associated with increased gametocyte clearance and combination therapy in areas where drug resistance is high or emerging may provide an additional means for reducing transmission.