Monkey malaria infection in humans: different monkey species are involved

9 June 2015

BPRC - 1. Monkey malaria infection in humans: different monkey species are involved

Humans can be infected with different species of the malaria parasite. These species were originally acquired from other primate hosts. Currently, in Southeast Asia, human infections caused by a primate malaria that has not been seen before in humans, Plasmodium knowlesi, are emerging. Genetic analyses of these infections shed light on the origin and the potential risks for spreading of this new pathogen for humans.

Human malaria is predominantly caused by four malaria species. However, recently, human infections with a fifth malaria parasite species have emerged in Southeast Asia. These infections are caused by Plasmodium knowlesi, a malaria parasite that naturally infects monkeys. This parasite can cause serious disease in humans and is currently responsible for the majority of malaria cases in Malaysia. Given the potential danger of further spreading of this type of malaria, for example through human-to-human mosquito transmission, it is imperative to understand the origin of these infections.

To this end, researchers have performed a genetic characterisation of a large amount of malaria samples from two monkey species and humans. They found that the two monkey species harboured two types of P. knowlesi. In the human samples, they found both parasite forms, which enhances the potential for further adaptation and spreading of this type of malaria. This study (, to which BPRC scientists have contributed, concludes that further studies of adaptations of this parasite and interventions to reduce transmission are urgent priorities.