Background: Imported cases of malaria constitute an important public health problem in many countries, even in those with autochthonous cases, where disease could be acquired in these areas and then seen in non-endemic regions. Non-immune populations are susceptible to complications due to malaria infection, particularly in malaria caused by Plasmodium falciparum. However, Plasmodium vivax the predominant Plasmodium spp. in Venezuela can also lead to severe malaria.
Methods: We reviewed retrospectively cases of malaria to identify the clinical features of those imported cases diagnosed at two institutions in Margarita Island (a non-endemic area), Venezuela, in an 8-year period. We conducted a retrospective observational study to identify the clinical and epidemiological features among hospitalized patients at Hospital Central and Hospital Agustin Hernández with malaria acquired at malaria-endemic locations.
Results: We identified eighteen imported cases of malaria confirmed by thin and thick peripheral blood smears at these two institutions over an 8-year period. The mean age of diagnosis was 27 years. P. vivax was responsible for the majority of cases. All patients presented with fever, 89% with malaise, 78% with chills, and 67% with myalgia, among others symptoms. Mean haemoglobin levels on admission were 8.1g/dL (100% <12g/dL); platelets: 79,283cells/mm(3) (89% had platelets below 150,000); and a mean total leukocyte count: 3.4x10(3)cells/mm(3) (78% had leukopenia). Thirty nine percent of patients required blood transfusions. Two fatalities were identified (CFR=11%), one associated to severe malaria due to P. falciparum and the other due to a complicated case of P. vivax malaria.
Discussion: Imported cases of malaria due to P. vivax and P. falciparum in the studied population are associated with significant hematological complications. These findings illustrate the importance of educating non-immune populations about the malaria risk and prevention strategies; and from a pubic health perspective, the need to develop further malaria prevention strategies at a national level.