STATE COLLEGE, Pa., Apr 7, 2009 (UPI via COMTEX) -- A U.S.-led study suggests
insecticides that would kill just older mosquitoes would be a better way of
controlling malaria.
Pennsylvania State University Professor Andrew Read said such an approach would
be a more sustainable way of controlling the disease and might lead to
evolution-proof insecticides that never become obsolete.
Each year malaria kills about a million people, but many of the chemicals used
to kill the insects become ineffective, the scientists said, since repeated
exposure to an insecticide breeds a new generation of mosquitoes that are
resistant to that particular chemical.
"Insecticides sprayed on house walls or bed nets are some of the most successful
ways of controlling malaria," said Read. "But they work by killing the insects
or denying them the human blood they turn into eggs. This imposes an enormous
selection in favor of insecticide-resistant mosquitoes."
Read, Penn State Professor Matthew Thomas and doctoral student Penelope Lynch of
The Open University in the United Kingdom say chemical or biological
insecticides that kill only older mosquitoes are a more effective way to fight
the deadly disease.
"It is one of the great ironies of malaria," said Read. "Most mosquitoes do not
live long enough to transmit the disease. To stop malaria, we only need to kill
the old mosquitoes."
The research appears in the journal PLoS Biology.
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