[Malaria imported by immigrants in Catalonia]

Area of Science:

• Tropical medicine
• Epidemiology
• Infectious diseases

Background:

• Malaria remains a significant global health concern, with imported cases frequently diagnosed in non-endemic regions.
• Immigrants from malaria-endemic areas represent a key population for imported malaria surveillance in Europe.

Purpose of the Study:

• To investigate the epidemiological features and clinical presentations of malaria among immigrants in Catalonia, Spain.
• To identify risk factors and specific Plasmodium species prevalent in this population.

Main Methods:

• Retrospective analysis of malaria cases diagnosed in immigrants at the Unit of Tropical and Imported Diseases "Drassanes", Barcelona (1990-1993).
• Diagnostic methods included thick blood film, peripheral blood smear, and Quantitative Buffy Coat (QBC) analysis.
• Data collected on patient origin, Plasmodium species, and clinical manifestations.

Main Results:

• 103 malaria cases were diagnosed in 100 immigrants (2,453 visited).
• Plasmodium falciparum was the most common species (70%), predominantly in individuals from sub-Saharan Africa (96%).
• Over one-third (36%) of malaria cases were asymptomatic, with P. falciparum infections in semi-immune individuals often being mild.

Conclusions:

• Routine malaria screening is recommended for immigrants from sub-Saharan Africa, irrespective of symptoms, due to high P. falciparum prevalence.
• Asymptomatic malaria, especially P. falciparum, is common in semi-immune immigrants and warrants diagnostic consideration.
• Targeted screening based on geographic origin can optimize resource allocation in imported malaria surveillance.