Increased incidence of cycloguanil resistance in malaria cases entering France from Africa, determined as point mutations in the parasites' dihydrofolate-reductase genes

The incidence of cycloguanil resistance in 501 Plasmodium falciparum isolat es from individuals entering France from Africa was estimated by a method b ased on PCR-restriction-fragment-length polymorphisms. None of the subjects had taken antifol prophylaxis. Annual incidence of the resistance, detecte d as a point mutation at codon 108 in the parasite's dihydrofolate-reductas e gene, increased from 19.8% in 1995 to 43.6% in 1997 (P<0.001). The propor tion of isolates found to be susceptible (i.e. wild-type) among travellers returning from the African countries known as Group 2 in France (i.e. Burki na Faso, Cdte d'Ivoire, Gambia, Ghana, Guinea, Liberia, Madagascar, Mali, M auritania, Niger, Senegal, Sierra Leone, Tchad and Togo) was reasonably hig h (62.9%) and much higher than in the other subjects returning from other i dentifiable countries in Africa (35.3%). The antimalarial prophylaxis recom mended in France to those travelling to Group-2 countries, chloroquine-prog uanil, therefore still seems reasonable, although cycloguanil resistance ma y seriously undermine the efficacy of this drug combination in the future.