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Varying efficacy of artesunate+amodiaquine and artesunate+sulphadoxine-pyrimethamine for the treatment of uncomplicated falciparum malaria in the Democratic Republic of Congo: a report of two in-vivo studies

Maryline Bonnet1*, Ingrid van den Broek23, Michel van Herp4, Pedro Pablo Palma Urrutia5, Chantal van Overmeir6, Juliet Kyomuhendo7, Célestin Nsibu Ndosimao8, Elizabeth Ashley2 and Jean-Paul Guthmann29

Author Affiliations

1 Epicentre, Rue de Lausanne 78, CH-1211 Geneva 21, Switzerland

2 Epicentre, 8 rue Saint Sabin, 70011, Paris, France

3 Center for Infectious Disease Control, National Institute for Public Health and the Environment, PO Box 1, 3720 BA Bilthoven, the Netherlands

4 Médecins Sans Frontières, Medical department, Brussels, Belgium

5 Médecins Sans Frontières, Medical department, Barcelona, Spain

6 Prince Leopold Institute of Tropical Medicine, Department of Parasitology, Antwerp, Belgium

7 Mbarara University of Science and Technology, Mbarara, Uganda

8 National Malaria Control Programme, Kinshasa, Democratic Republic of Congo

9 Unité des Maladies à Prévention Vaccinale, Département des Maladies Infectieuses, Institut de Veille Sanitaire (INVS), 12, rue du Val d'Osne, 94415 Saint-Maurice cedex, France

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Malaria Journal 2009, 8:192  doi:10.1186/1475-2875-8-192

Published: 10 August 2009



Very few data on anti-malarial efficacy are available from the Democratic Republic of Congo (DRC). DRC changed its anti-malarial treatment policy to amodiaquine (AQ) and artesunate (AS) in 2005.


The results of two in vivo efficacy studies, which tested AQ and sulphadoxine-pyrimethamine (SP) monotherapies and AS+SP and AS+AQ combinations in Boende (Equatorial province), and AS+SP, AS+AQ and SP in Kabalo (Katanga province), between 2003 and 2004 are presented. The methodology followed the WHO 2003 protocol for assessing the efficacy of anti-malarials in areas of high transmission.


Out of 394 included patients in Boende, the failure rates on day 28 after PCR-genotyping adjustment of AS+SP and AS+AQ were estimated as 24.6% [95% CI: 16.6–35.5] and 15.1% [95% CI: 8.6–25.7], respectively. For the monotherapies, failure rates were 35.9% [95% CI: 27.0–46.7] for SP and 18.3% [95% CI: 11.6–28.1] for AQ. Out of 207 patients enrolled in Kabalo, the failure rate on day 28 after PCR-genotyping adjustment was 0 [1-sided 95% CI: 5.8] for AS+SP and AS+AQ [1-sided 95% CI: 6.2]. It was 19.6% [95% CI: 11.4–32.7] for SP monotherapy.


The finding of varying efficacy of the same combinations at two sites in one country highlights one difficulty of implementing a uniform national treatment policy in a large country. The poor efficacy of AS+AQ in Boende should alert the national programme to foci of resistance and emphasizes the need for systems for the prospective monitoring of treatment efficacy at sentinel sites in the country.