- Researchers in west Africa are monitoring a worrying development for malaria-control efforts: the rise of insecticide resistance in mosquitoes in the region. Adele Baleta reports from Burkina Faso.
- Insecticide resistance is one of the biggest threats to sustainable malaria control in Africa. Up to 1 million Africans, mostly children younger than 5 years and pregnant women, die from malaria each year, according to Roll Back Malaria estimates. Meanwhile, 500 million cases of malaria-related illness on the continent have, and will continue to have, a devastating effect on the productivity of African economies.
- Sodiomon Sirima, interim director of the Centre National de Recherche et de Formation sur le Paludisme (CNRFP) based in the Burkinabe capital Ouagadougou, says that with a long history of crop spraying, malaria vectors, mainly the deadly Anopheles gambiae, have developed increasing resistance to dichlorodiphenyltrichloroethane (DDT) and pyrethroids.
- Control of Anopheles mosquitoes relies mainly on the use of pyrethroid-impregnated bednets and there are fears that the emergence of insecticide resistance will compromise their efficacy. DDT is used for indoor residual spraying in many countries but not in Burkina Faso, which has not started spraying.
- “Compared to east and central Africa our rainy season is short and the transmission rates are high. On average there are 300 infective bites per person per year in the rural areas (50 in East Africa) and about 10 per person per year in urban areas”, says Sirima.
- About 15 000 children younger than 5 years die every year from malaria. Sirima says all children in this age group have a minimum of two episodes a year. Malnutrition compounds the problem. During the rainy season and depending on the area, about 76% of children in this age group have been found to be infected using microscopy and this increases to almost 100% using the more expensive PCR test. For the general population these proportions are 40% and 60%, respectively.
- Global Fund to Fight AIDS, Tuberculosis and Malaria has secured 6 million nets (at US$5 per net) but there is a shortfall of $2·5 million that is needed for transporting and distributing the nets. Advocacy and training of staff and volunteers have to be factored in as well.
The Lancet, Volume 374, Issue 9701, Pages 1581 - 1582, 7 November 2009
doi:10.1016/S0140-6736(09)61933-4http://www.thelancet.com/journals/lancet/article/PIIS0140-6736%2809%2961933-4/fulltext#article_upsell
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