Scientists Lift Hopes in Malaria War

European scientists have identified a new way to stop malaria in its tracks. Instead of preventing the malaria parasite from infecting humans, they could instead stop the parasite from infecting the mosquito that spreads the lethal disease.

Researchers are working on prophylactics, vaccines, mosquito eradication programmes and preventive measures such as nets. In 2002, scientists completed the entire DNA sequences of both the Anopheles mosquito and the plasmodium parasite that it carries, in the hope that genetic research might open new avenues.

Now a team from the European Molecular Biology Laboratory (EMBL) in Heidelberg report in the US journal Science today that they have homed in on four mosquito proteins that affect the ability of the malaria parasite to survive in its host.

"Many researchers focus on the direct effects of plasmodium on the human body, but the mosquito is an equally important battleground in fighting the disease," said Fotis Kafatos, director of EMBL and leader of the malaria research team. "We see a way to potentially stop the parasite in its tracks."

The mosquito picks up the parasite by feeding on an infected human. After three weeks in the mosquito's gut, the parasite moves to its salivary glands. The next time the mosquito drinks blood, the parasite infects a new victim. But researchers have been puzzled because some species transmit malaria while some do not. The latest research has delivered the answer: two of the newly-identified proteins, TEP1 and LRIM1, kill the parasite in the mosquito's gut. Two others have the opposite effect.

"These studies are the first to show the power of the mosquito's immune system and give us some options for fighting the disease in the insect before it has a chance to be passed to a human," said Prof Kafatos.