Field research, relief work and war: does chloroquine-resistance occur in displaced populations of southern Sudan?

Efficacy of two artemisinin combination therapies for uncomplicated falciparum malaria in children under 5 years, Malakal, Upper Nile, Sudan

Background

The treatment for Plasmodium falciparum malaria in Sudan has been in process of change since 2003. Preceding the change, this study aimed to determine which artemisinin-based combination therapies is more effective to treat uncomplicated malaria in Malakal, Upper Nile, Sudan.

Methods

Clinical trial to assess the efficacy of 2 antimalarial therapies to treat P. falciparum infections in children aged 6–59 months, in a period of 42 days after treatment.

Results

A total of 269 children were followed up to 42 days. Artesunate plus Sulfadoxine/Pyrimethamine (AS+SP) and Artesunate plus Amodiaquine (AS+AQ) were both found to be efficacious in curing malaria infections by rapid elimination of parasites and clearance of fever, in preventing recrudescence and suppressing gametocytaemia. The combination of AS+SP appeared slightly more efficacious than AS+AQ, with 4.4% (4/116) versus 15% (17/113) of patients returning with malaria during the 6-week period after treatment (RR = 0.9, 95% CI 0.81–0.96). PCR analysis identified only one recrudescence which, together with one other early treatment failure, gave efficacy rates of 99.0% for AS+AQ (96/97) and 99.1% for AS+SP (112/113). However, PCR results were incomplete and assuming part of the indeterminate samples were recrudescent infections leads to an estimated efficacy ranging 97–98% for AS+SP and 88–95% for AS+AQ.

Conclusion

These results lead to the recommendation of ACT, and specifically AS+SP, for the treatment of uncomplicated falciparum malaria in this area of Sudan. When implemented, ACT efficacy should be monitored in sentinel sites representing different areas of the country.

History, dynamics, and public health importance of malaria parasite resistance

Despite considerable efforts, malaria is still one of the most devastating infectious diseases in the tropics. The rapid spread of antimalarial drug resistance currently compounds this grim picture. In this paper, we review the history of antimalarial drug resistance and the methods for monitoring it and assess the current magnitude and burden of parasite resistance to two commonly used drugs: chloroquine and sulfadoxine-pyrimethamine. Furthermore, we review the factors involved in the emergence and spread of drug resistance and highlight its public health importance. Finally, we discuss ways of dealing with such a problem by using combination therapy and suggest some of the research themes needing urgent answers.