Transfusion-transmitted malaria in Ghana
Corresponding author: Alex Owusu-Ofori, Address: Komfo Anokye Teaching Hospital, Box 1934, Kumasi, Ghana. Email: email@example.com; Tel: +233 209149370
Background. In sub-Saharan Africa, the prevalence of malaria parasitaemia in blood donors varies from 0·6% to 50%. Althoughthe burden of transfusion-transmitted malaria (TTM) in malaria-endemic countries is unknown, it is recommended that all donated blood is screened for malaria parasites. This study aimed to establish the incidence of TTM and identify a suitable screening test.
Methods. Pregnant women, children and immunocompromised malaria –negative transfusion recipients in a teaching hospital in Ghana were recruited over the course of one year. Parasites detected in recipients within 14 days of the transfusion were genotyped and compared to parasites in the transfused blood. The presence of genotypically identical parasites in the recipient and the transfused blood confirmed transfusion-transmitted malaria. Four malaria screening tests were compared to assess their usefulness in the context of African blood banks.
Results. Of the 50 patients who received transfusions that were positive for P. falciparum by PCR, seven recipients developed PCR-detectable parasitaemia. In only one of the 50 recipients (2%) was the parasite identical to that in the transfused blood. The prevalence of P. falciparum malaria in transfused blood was 4·7% (21/445) by microscopy, 13·7% (60/440) by rapid diagnostic test, 18% (78/436) by polymerase chain reaction and 22·2% (98/442) by enzyme immunoassay.
Conclusions. Although malaria parasites are commonly detected in blood donors in malaria endemic areas, transfusion-transmitted malaria occurs infrequently. Policies recommend screening blood donors for malaria but none of the commonly used methods is sufficiently sensitive to be used by blood banks in malaria endemic countries.