Nearly 30 years after safety concerns led to the phasing out of indoor spraying with DDT and other insecticides to control malaria, the United Nations health agency said today it will start promoting this method again to fight the global scourge that kills more than one million people every year, including around 3,000 children everyday.
“The scientific and programmatic evidence clearly supports this reassessment. Indoor residual spraying is useful to quickly reduce the number of infections caused by malaria-carrying mosquitoes,” said Dr Anarfi Asamoa-Baah, World Health Organization (WHO) Assistant Director-General for HIV/AIDS, TB and Malaria.
“Indoor residual spraying has proven to be just as cost effective as other malaria prevention measures, and DDT presents no health risk when used properly.” Indoor residual spraying is the application of long-acting insecticides on the walls and roofs of houses and domestic animal shelters.
“We must take a position based on the science and the data,” said Dr Arata Kochi, Director of WHO’s Global Malaria Programme. “One of the best tools we have against malaria is indoor residual house spraying. Of the dozen insecticides WHO has approved as safe for house spraying, the most effective is DDT.”
WHO actively promoted indoor residual spraying for malaria control until the early 1980s when increased health and environmental concerns surrounding DDT caused the organization to stop promoting its use and to focus instead on other means of prevention. Extensive research and testing has since demonstrated that well-managed indoor residual spraying programmes using DDT pose no harm to wildlife or to humans, the agency said.
Views about the use of insecticides for indoor protection from malaria have been changing in recent years. Environmental Defense, which launched the anti-DDT campaign in the 1960s, now endorses the indoor use of DDT for malaria control, as does the Sierra Club and the Endangered Wildlife Trust.
At a news conference today, the WHO also called on all malaria control programmes around the world to develop and issue a clear statement outlining their position on indoor spraying with long-lasting insecticides such as DDT, specifying where and how spraying will be implemented in accordance with WHO guidelines.
Every year, more than 500 million people suffer from acute malaria, resulting in more than one million deaths. At least 86 per cent of these deaths are in sub-Saharan Africa. Globally an estimated 3,000 children and infants die from malaria every day and 10,000 pregnant women die from malaria in Africa every year. Malaria disproportionately affects poor people, with almost 60 percent of malaria cases occurring among the poorest 20 per cent of the world’s population.