[Malaria imported to Norway 1989-98]

Abstract

Background: Increasing numbers of imported cases of malaria have been reported from several European countries.

Material and methods: By analysing data from the Norwegian Surveillance System for Communicable Diseases (MSIS) from 1989 to 1998, the incidence of imported malaria and the most important risk groups for acquiring the disease in endemic areas are assessed.

Results: In the ten-year period a total of 744 cases of malaria imported into Norway were reported. An increase in incidence has been observed during the period. Since 1992 Plasmodium falciparum has been the most common reported parasite. 58% of the cases were among people of non-Norwegian origin, and 41% among people of Norwegian origin. Immigrants from Pakistan, India and Sri Lanka constitute 26% of all imported cases. During the five year period from 1994 to 1998, 60% of patients of non-Norwegian origin, and 19% of patients of Norwegian origin took no chemoprophylaxis prior to their illness. From 1994 to 1998, 23% of the patients developed malaria despite taking recommended chemoprophylaxis. The majority of these patients used chloroquine and proguanil and developed falciparum malaria after visiting sub-Saharan Africa.

Interpretation: Increased emphasis should be put on avoiding exposure to mosquitoes while in endemic areas. Mefloquine should be recommended as prophylaxis to the majority of travellers visiting regions with chloroquine-resistant malaria.