Falciparum malaria, imported into The Netherlands, 1979-1988. II. Clinical features.

To study the clinical features in patients with falciparum malaria and the influence of chloroquine chemoprophylaxis on these features, a prospective study was carried out of all non-immune patients with falciparum malaria between 1979 and 1988. Three hundred and sixty-one consecutive non-immune patients with falciparum malaria who were seen at the outpatient-department for Tropical Diseases, Royal Tropical Institute, and Division of Infectious Diseases and Tropical Medicine of the University Hospitals of the University of Amsterdam, The Netherlands. Compliance with the recommended malaria prophylaxis was claimed by 47% (168/361); 24% (86/361) had not taken any chemoprophylaxis. The first group had a milder illness, less often parasitaemia > or = 1% and suffered less from complications. Comparison of the clinical features in patients who did not take prophylaxis and those who, during recommended prophylaxis, appeared to be infected with a chloroquine-resistant strain strengthened the evidence of a protective effect of chloroquine. Complications occurred in 14% of patients; pregnant women were at higher risk of complicated malaria; the case-fatality rate was low (0.3%). It is concluded that chloroquine prophylaxis still may have--depending on the degree of chloroquine-resistance--a protective effect on the clinical features and this modulating effect needs to be further investigated.