Background: Imported malaria remains an important, but often unrecognised, health problem in Europe. Little information exists on the incidence of imported malaria with respect to exposure. This study aimed to estimate the incidence of malaria in a cohort of travellers with respect to protection measures.
Method: In all 13,017 participants enrolled in a French general population cohort (SU.VI.MAX cohort) and followed-up over 8 years were investigated. All participants received a retrospective questionnaire about travel to malaria-endemic countries relating to countries visited, duration of stay, use of protection measures and chemoprophylaxis. Malaria cases was confirmed from medical records.
Results: Data were obtained for 752 individuals who made 1,393 trips to malaria-endemic areas. This sample was predominantly middle-class and high-risk groups such as migrants were not represented. Mechanical protection was used in 589 trips (42.3%) and chemoprophylaxis in 1,017 trips (73.0%). This was appropriate for the zone in 615 trips (44.0%) and adequate compliance was reported in the case of 497 trips (35.6%). Appropriate chemoprophylaxis and physical protection measures were used in 21.7% of the trips. Six laboratory-confirmed cases of imported malaria yielded an estimated incidence density of 148 cases/month of exposure/10,000 travellers. In five cases, appropriate protection measures had not been taken.
Conclusion: Appropriate chemoprophylaxis and physical protection measures against malaria infection are used by less than one-quarter of a sample of predominantly middle-class travellers from France to endemic areas. More intense education measures need to be implemented to reduce the risk of imported malaria.