New parasite insight could aid anti-malaria fight

By Will Dunham

WASHINGTON, Feb 28 (Reuters) - Scientists have achieved a greater understanding of the internal workings of the deadly malaria parasite with an eye toward developing better drugs to fight the disease, a study published on Wednesday stated.

Malaria, a mosquito-borne disease caused by a parasite, occurs throughout tropical and sub-tropical regions of the world, killing at least a million people annually, most of them young children in sub-Saharan Africa.

A team at Drexel University College of Medicine in Philadelphia led by Akhil Vaidya looked at internal structures called mitochondria in Plasmodium falciparum, the deadliest of the four types of the parasite that cause malaria in people.

Mitochondria generally act as a cell's power plant -- producing usable energy from oxygen taken in by respiration. The researchers said this parasite's mitochondria do not generate energy but still consume oxygen -- and the question was why.

The researchers, writing in the journal Nature, determined that what the parasite's mitochondria were doing instead of producing energy was providing DNA to enable the parasite to replicate itself.

"Cheaper antimalarial drugs are needed to be developed on a continuous basis for us to keep up with the emergent resistant strains. A better understanding of the mitochondrial physiology would guide efforts to derive new antimalarial drugs," wrote Vaidya, a professor of microbiology and immunology, in an e-mail from India.

The findings also help explain how the antimalarial drug, GlaxoSmithKline Plc's (GSK.L) Malarone, works, the researchers said.

Malaria has become resistant to some drugs, and work on a vaccine has been slow. Bed nets to protect against mosquito bites, insecticides and antimalarial drugs are effective ways to combat malaria.

"In general, malaria is a disease of poverty and the populations are caught in the vicious cycle of disease and deprivation," added Vaidya. "The parasite also presents itself as a moving target to our immune system, so the immunity to the parasite is slow to develop and short-lived."

Malaria also is intertwined with the AIDS epidemic in Africa. Recent research showed that people with malaria are more likely to transmit to sex partners the virus that causes AIDS.