Malaria in non-endemic areas

Abstract

Globally, Plasmodium vivax and P. falciparum malaria are the most important causes of malaria. Falciparum malaria is generally the most severe form of disease which causes the majority of malaria deaths. Nevertheless, vivax and knowlesi malaria can also result in severe disease and even mortality. In most case series from Europe and North America, malaria frequently comes up as the commonest cause of fever in the returned travellers. Although malaria is not the commonest cause of fever in the returned travellers in Hong Kong, it is a diagnosis that must not be missed because fatalities due to falciparum malaria do occur regularly, and some of these cases in the past had been related to delays in diagnosis or initiating treatment. Malaria must be considered in any sick returned traveller who had stayed in an endemic area. The shortest incubation period for falciparum malaria is 7 to 8 days. There are no pathognomonic symptoms and signs of malaria. Malaria is often mis-diagnosed as other diseases such as respiratory tract infection, gastroenteritis, or bacterial sepsis. The classical periodic fever is present in only a minority of patients at the time of presentation. One should be aware of common pitfalls in the diagnosis and treatment of malaria. Patients with severe malaria should be treated and monitored in intensive care settings. For severe malaria, intravenous artemisinin is the drug of choice because of its rapid clearance of parasitaemia. Radical cure with primaquine should be offered to patients with vivax and ovale malaria after checking the glucose-6-phosphate dehydrogenase status.