Recent advances in the management of Plasmodium knowlesi infection.

Plasmodium knowlesi (P. knowlesi) has been detected to be the fifth malarial parasite that can cause malaria in human beings. The parasite is known to commonly infect macaque monkeys. The infection is highly prevalent in South-East Asia. It has morphologic similarities to Plasmodium malariae and Plasmodium falciparum. P. knowlesi is known to replicate every 24 h in the human host and hence, causes "quotidian malaria." It causes a wide spectrum of clinical manifestations and sometimes can cause fatal illness. Chloroquine is effective in the treatment of uncomplicated P. knowlesi infection. Severe and complicated P. knowlesi malaria can be managed with artemisinin combination therapy.