Imported malaria in Bordeaux: evaluation of the risk of infection with Plasmodium falciparum as a function of country visited

This study of imported cases of malaria, which was carried out in Bordeaux (France) in 1987-89, emphasizes the major part played by Plasmodium falciparum, especially in areas lying south of the Sahara in Africa, from where falciparum malaria is mainly imported to other countries. The study of these imported cases is strengthening our understanding of the epidemiology of malaria in relation to the country or area, whether the transmission occurs without interruptions or seasonally. The number of cases of P. falciparum per 1000 travellers (seen for vaccination against yellow fever at Bordeaux) gives an index for evaluating the risk of malaria. This risk changes with the epidemiological profile of falciparum malaria in the three major African ecosystems (rain forest, savannah, and sahelian belts), and is related to the progression of chloroquine resistance in Africa and influenced by the type of chemoprophylaxis proposed to travellers. The use of mefloquine for stays shorter than one month in Central Africa reduced the risk of malaria in 1988 and 1989, compared to 1987. [Editorial note. Recent data indicate some undesirable side-effects of mefloquine, e.g., its use during early pregnancy could lead to congenital defects.] Appropriate chemoprophylaxis and advice to travellers to areas lying south of the Sahara are therefore more and more necessary in order to arrest the increase in the number of imported falciparum malaria cases and reduce the number of serious cases, which are costly in terms of public health.