[Transfusion-induced malaria: risks, prevention and cost (1 year's experience)]

Area of Science:

• Medical Parasitology
• Transfusion Medicine
• Epidemiology

Background:

• Transfusion-induced malaria (paludism) poses a risk, with cases documented in Rouen.
• Previous prevention strategies relied on donor history, such as time elapsed since return from endemic areas.

Purpose of the Study:

• To evaluate the effectiveness of serological screening for identifying blood donors at risk of transmitting malaria.
• To compare serological screening with the existing 5-year exclusion rule for blood donors returning from malarial zones.

Main Methods:

• A survey of 51,000 blood samples identified 1,020 donors with a history of living in malarial endemic zones.
• Indirect immunofluorescence testing was used to detect antibodies against malaria parasites in selected donors.
• Results were analyzed based on geographical origin, ethnicity, time since return, and chemoprophylaxis use.

Main Results:

• 92 out of 1,020 screened donors (approximately 9%) had a positive indirect immunofluorescence titer (> 1:20) and their blood was excluded.
• The 5-year exclusion rule would have incorrectly excluded 1.4% of donors, while serological screening identified only 0.18% of donors requiring exclusion.
• Fourteen donors returning from endemic areas for over 5 years had positive serology, highlighting limitations of the current exclusion period.

Conclusions:

• Serological screening, specifically indirect immunofluorescence, is a more accurate method for identifying blood donors potentially carrying malaria parasites.
• The current 5-year exclusion rule is both overly restrictive and insufficiently protective.
• A combined approach of donor inquiry and malarial serology is recommended for improved prevention of transfusion-induced malaria.