[Falciparum malaria in Oslo and Akerhus].

Background: Imported falciparum malaria in an increasingly frequent health problem in many areas in which it is not endemic. Complications are commonly seen, and reported case-fatality rates may exceed 3%.

Material and Methods: The study is a medical chart-based retrospective study of all cases of falciparum malaria diagnosed in Oslo and Akershus counties, south-eastern Norway, 1988-1997.

Results: We identified 232 diagnosed cases; of these, records were available for 222 cases (95%). The incidence rate almost quadrupled during the study period. The two largest groups were immigrants visiting their country of origin (35%) and Norwegian tourists (29%). 95% of the cases were infected in Sub-Saharan Africa. There were no fatal cases, and only eight cases (3.6%) developed complicated falciparum malaria. In a statistical analysis, the following factors were found to be significantly associated with complicated disease: higher age, noncompliance to recommended chemoprophylaxis in assumed non-immune subjects, prolonged doctor's delay and prolonged diagnostic delay.

Interpretation: The study suggests that complications in imported falciparum malaria may largely be prevented by a high rate of chemoprophylaxis compliance in non-immune travellers and a high awareness of this possibility among physicians evaluating febrile travellers from endemic areas.