Insecticide resistance threat to malaria fight

Wed, May 16, 2012, 01:00

LONDON – Malaria-carrying mosquitoes in Africa and India are becoming resistant to insecticides, putting millions of lives at greater risk and threatening eradication efforts, health experts said yesterday.

While existing prevention measures such as mosquito nets treated with insecticide and indoor spraying are still effective, experts said tight surveillance and rapid response strategies were needed to prevent more resistance from developing.

Despite decades of efforts to beat malaria with insecticides, bednets and combination drugs, the disease still kills more than 650,000 people a year, most of them babies and children in sub-Saharan Africa.

Because the disease is spread by anopheles mosquitoes, insecticides are a vital part of controlling it.

Publishing a plan to help countries tackle the threat, the World Health Organisation’s global malaria programme said resistance had been detected in 64 countries.

“We think we’re ahead of the curve. The tools we have today work extremely well in almost all settings, so we don’t want people throwing their hands up in the air and saying this is a catastrophe,” Robert Newman, the programme’s director, said.

“But we have identified resistance – it is a problem out there – and we need to take urgent and concerted action to make sure we maintain the effectiveness of the tools.”

The WHO recommends four main classes of insecticides, the most common of which are pyrethroids. But resistance to at least one of these classes has now been detected in all regions where the disease is endemic.

A study published last year found that mosquitoes in one region of Senegal swiftly developed resistance to bednets treated with deltamethrin, a pyrethroid.

WHO director general Margaret Chan said the levels of resistance found in Africa and India were of greatest concern. “These countries are characterised by high levels of malaria transmission and widespread reports of resistance,” she said. In some places there was resistance to all four classes of insecticide. – (Reuters)