Scientists have identified a new target in the parasite that causes malaria, a
disease that causes more than a half a million deaths annually.
Potential drugs can aim at
a newly-discovered enzyme that the parasite uses to metabolise energy at every
stage of its infection in humans, they said.
The finding, published in
the journal Nature, is important because only a tiny handful of weaknesses have
been found that apply to every stage of the complex process by which the
Plasmodium parasite grows and multiplies in the body.
Most drugs aim at specific
stages in the parasite's cycle, not all.
They notably fail to wipe
out early forms of the parasite called hypnozoites that remain dormant in the
liver and then revive, triggering a malarial relapse.
The new target, called
phosphatidylinositol-4-kinase, or PI4K, is an enzyme that the parasite needs to
survive in host cells.
Most drugs selective
selectively work on certain stages of the (parasite's) life cycle, but not all
stages," said Case McNamara, a genomics specialist at the Novartis
Research Foundation in San Diego, California.
"Inhibitors of this
drug target have the potential to not only cure individuals of a malaria
infection, but also to prevent infections and even block transmission of the
parasite back to the mosquito."
The only drug that is
currently licensed to wipe hypnozoites is primaquine.
Licensed more than half a
century ago, the formula is considered a last-throw-of-the-dice option, as it
can cause potentially life-threatening anaemia for people with an inherited
According to the UN's World
Health Organisation (WHO), 219 million people became infected with malaria in
2010, of whom 660 000 died, most of them African children under the age of