[A fifth plasmodium that can cause malaria].
BACKGROUND
Since 2004, malaria with a "fifth" plasmodium, Plasmodium knowlesi (common in macaque monkeys), has been diagnosed in a number of people in Southeast Asia. This article gives a short overview of the epidemiology, clinical picture, diagnostics and treatment of P. knowlesi infection.


METHODS
The article is mainly based on articles published in international journals during the last five years.


RESULTS
Most cases have been diagnosed in the Malaysian state Sarawak on the island of Borneo. The disease usually presents in the same way as other types of malaria, with the exception that fever spikes comes at 24-hour intervals. Microscopy findings resemble those for P. malariae in the early phase of the disease and many patients have been diagnosed wrongly. Without treatment a serious clinical picture may develop, blood findings may be as serious as for P. falciparum infection and death may occur. Chloroquine tablets are indicated in light infections, while parenteral therapy with artesunate or quinine is necessary in seriously affected patients. P. knowlesi infection has been reported among tourists in Malaysia.


CONCLUSIONS
The risk of contracting P. knowlesi infection as well as other types of malaria is low in Malaysia and other regions where P knowlesi occurs.
Myrvang
Bjørn
B
Kompetansesenter for import- og tropesykdommer, Oslo universitetssykehus, Ullevål 0407 Oslo, Norway. bjmy@uus.no
D000818:Animals; D000962:Antimalarials / Q000627:therapeutic use; D001893:Borneo / Q000453:epidemiology; D006801:Humans; D008251:Macaca / Q000469:parasitology; D008288:Malaria / Q000175:diagnosis / Q000188:drug therapy / Q000453:epidemiology / Q000469:parasitology; D008296:Malaysia / Q000453:epidemiology; D016790:Plasmodium knowlesi / Q000472:pathogenicity*; D012307:Risk Factors; D057236:Travel Medicine
D000962:Antimalarials