Anti-Malaria Efforts Yield New Success
Friday, February 1, 2008
Widespread use of insecticide-treated mosquito nets and state-of-the-art drugs has succeeded in cutting malaria deaths in half in two countries most heavily affected by the disease, the World Health Organization is reporting today.
The findings from Rwanda and Ethiopia are the first to show a greater than 50 percent reduction in malaria mortality nationwide in "high burden" countries. Such dramatic reductions had been achieved previously only in smaller regions or in countries where the disease is less pervasive.
The results suggest what may be possible in dozens of other countries, and they are likely to spur efforts already underway to roll out the relatively low-cost measures.
Malaria is responsible for 2 percent of all deaths worldwide and 9 percent of deaths in Africa. Each year, about 1.1 million deaths -- almost all in children -- are directly attributable to the disease, and at least a million more occur from complications such as severe anemia. In Africa, where most cases occur, malaria costs $12 billion a year in medical expenses and lost productivity.
"This is the first time we have seen these results with the new tools," said Arata Kochi, head of malaria programs for WHO.
"This is a genuinely historic achievement," said Richard G.A. Feachem, former director of the Global Fund to Fight AIDS, Tuberculosis and Malaria who is now the director of the Global Health Group at the University of California at San Francisco. "This is not theoretical. We do not have to wait for a vaccine or new drugs. If we implement today's technologies aggressively on a national scale, we will have a big impact."
Two key items in the current "tool kit" are bed nets treated with insecticide that lasts as much as five years, and treatment with at least two drugs, one of them artemisinin, a compound derived from a Chinese herbal medicine.
The nets repel or kill mosquitoes and work even if they have holes in them. When used by 80 percent of households, the nets can reduce infections in African villages even among people who do not have them, a phenomenon similar to the "herd immunity" provided by vaccines. Artemisinin-containing therapies (ACTs) are oral drugs that work quickly and are often life-saving when the brain is infected by the malaria parasite.
WHO epidemiologists looked at the effect of nets and medicine in Rwanda, Ethiopia, Zambia and Ghana. Those countries' success in implementing the measures varied, and the drops in cases and deaths differed accordingly.
The most striking results were seen in Rwanda, in Central Africa, where an unplanned "natural experiment" unfolded in 2006.
That September, 3 million nets were given to households with children younger than 5 or pregnant women. The next month, artemisinin-based therapies were stocked in all public hospitals and clinics, where more than three-quarters of Rwanda's more than 9 million people get medical care.
Within two months, malaria cases and deaths were falling steeply. By 2007, the number of hospitalized children younger than 5 was 64 percent lower than in comparable periods in 2005, and deaths were 66 percent lower.