Imported malaria in adults and children:: Epidemiological and clinical characteristics of 380 consecutive cases observed in Verona, Italy

Background. Since the year 2000, in Italy, there has been a constant decrease in the number of cases of imported malaria in immigrants. Nevertheless, immigrants still account for about 70% of reported cases. To our knowledge, no data are yet available on imported malaria in children. This paper describes the main characteristics of malaria cases observed in recent years in the three main hospitals in Verona (roughly representing 10% of all cases reported in Italy in the period), with a special focus on the poorly known problem of imported malaria in children. Method. All malaria cases occurring from 2000 to 2004 were retrospectively examined. Semi-immune and nonimmune patients were analyzed for clinical, laboratory, and parasitological findings. A separate analysis was carried out for children who traveled to endemic areas to visit relatives and friends (VRF) and children born in endemic countries who came to Italy for immigration purposes. Results. A total of 380 cases of imported malaria occurred in Verona in the 5-year period, 43 being children. Semi-immune patients had a significantly lower parasitemia (p = 0.0032) and parasite clearance time and significantly shorter fever duration than nonimmune (p = 0.025 and p = 0.0026). VRF children presented significantly higher parasitemia and significantly lower platelet count (p = 0.016 and p = 0.042) than recent immigrants. Parasitemia clearance time and fever duration were longer in VRF children than in recent immigrants (p = 0.014 and p = 0.0085). We observed 23 cases of severe malaria, including 4 cases in immigrants. Conclusions. Our data confirm a significant difference both in clinical and in parasitological findings between semi-immune and nonimmune patients. We identified two populations of immigrant children: semi-immune (recent immigrants) and nonimmune (VRF). The latter is a high-risk group for severe malaria. Educational actions should be specially designed for immigrants traveling to VRF, focusing on the risk of severe malaria for both adults and children.