Cattle used to fight malaria

Treating cattle with insecticides could be cost effective

Scientists have discovered a cheap and effective way of controlling mosquitoes in South Asia - sponging cattle with insecticide.

The usual method of controlling malaria carrying mosquitoes is to spray houses with insecticide.

But this is becoming increasingly expensive for the region, which is looking for new methods of control.

As the region's malarial mosquitoes are zoophilic - they feed predominately on animals and only secondarily on humans - scientists decided to look at treating the cattle instead of people's homes.

The technology is simple and can be safely implemented by the community

Mark Rowland
London School of Hygiene and Tropical Medicine

Six settlements of Afghan refugees in the Hangu Valley, on Pakistan's Northwest Frontier Province, had their cattle sponged periodically with deltamethrin over three malarial seasons.

Mark Rowland, of the disease control and vector biology unit, at the London School of Hygiene and Tropical Medicine, found local strains of mosquito - the Anopheles stephensi and Anopheles culicifacies - preferred to drink the blood of the cattle.

He found that cattle sponging was just as effective as the home spraying, but 80% cheaper.

It could also be carried out quickly and safely by locals.

The flies in South Asia feed mainly on domestic animals

Mr Rowland also found that the deltamethrin was effective in killing ticks and that the cattle thrived - growing plumper and producing far more milk.

"We believe that livestock sponging is a new way to control malaria where vectors are zoophilic and feed predominantly on cattle.

"The technology is simple and can be safely implemented by the community."

Beneficial effects

Dr Pierre Guillet, of the World Health Organisation, said the study, published in The Lancet, was exciting and innovative and could provide the answer to the malaria problem in South Asia.

But he said it would not be applicable in Africa where they have a different sort of mosquito.

"It is very interesting and very effective. The product is safe and does not produce any significant risk.

"It does not contaminate the meat and the cattle put on weight and produced more milk.

"By treating the cattle it is a very strong incentive for people to implement this."

He said he now wanted to see the study extended to the rest of the region.