Malaria parasite reveals old age

A new genetic analysis of the malaria-causing Plasmodium falciparum has thrown into question the origin and evolution of the deadly parasite.

From several recent studies, some biologists had concluded that the mosquitoborne parasite first began killing significant numbers of people within the past 12,000 years or so. This complemented DNA studies of P. falciparum that suggested that the modern form of the parasite had arisen around that time (SN: 11/10/01, p. 296: The Seeds of Malaria).

A research group headed by Xin-zhuan Su of the National Institute of Allergy and Infectious Diseases in Bethesda, Md., conducted a new analysis of the parasite’s DNA and found surprising variability within its genes, indicating a much earlier origin. In the July 18 Nature, Su’s team estimates that P. falciparum dates back 100,000 to 180,000 years. “We have shown that the P. falciparum population is quite ancient and diverse, a result that will be important in the development of drugs and vaccines,” the biologists conclude.