Plasmodium knowlesi malaria: Overview Focussing on Travel-Associated Infections

In 2004, Plasmodium knowlesi was first recognised as a relevant cause of human malaria in Southeast Asia. Since then, P. knowlesi has been described from all Southeast Asian countries except Laos and has become well-established as the fifth human malaria parasite and the first significant zoonotic Plasmodium species. As countries endemic for P. knowlesi malaria are among the most popular and most highly visited international destinations, travel medicine experts should be aware about disease and risks including prophylactic and therapeutic measures. Between 2005 and 2012, 15 cases of P. knowlesi malaria have been recognised and published in international travellers. Male gender and travel to rural/forested areas with contact to wild monkeys are risk factors for P. knowlesi infection. The present review gives an overview on current literature on the P. knowlesi parasite and summarises recent findings related to epidemiology, diagnostics, treatment and prophylaxis focussing on travellers.