Introduction: Plasmodium falciparum malaria is the most aggressive form of this disease, with 90% of cases occurring in Africa. Only natives of malaria-endemic areas can acquire a certain degree of immunity to the disease. It is not known whether immunity is lost when contact with the parasite is discontinued.
Patients and methods: Retrospective study of cases of falciparum malaria imported from Africa, performed in Hospital Clinic, Barcelona (Spain), from 1999 to 2005. Clinical, epidemiological and laboratory parameters were compared between travelers and African immigrants.
Results: Among 187 patients, 85 were immigrants from an endemic area who had been living in a non-endemic area for more than 5 years. These patients presented fewer complications than travelers.
Discussion: These data may point to a certain persistence of immunity in previously semi-immune persons who migrate to non-endemic areas.