Malaria parasitemia in apparently healthy blood donors in north-central Nigeria.

Objective: To determine the prevalence of transmissible malaria in apparently healthy blood donors in the city of Jos in north-central Nigeria.

Methods: We collected blood specimens from individuals who had passed the screening criteria for blood donation. We created thin and thick blood films using the blood film template provided by the World Health Organization (WHO). The films were allowed to air dry; then, we stained them using a 3% Giemsa solution and examined them microscopically. In specimens that tested positive the malaria species was identified.

Results: The highest prevalence of malaria was in donors aged between 31 and 40 years (65.1%), whereas the lowest prevalence was in donors aged 20 years or younger (25.0%). Plasmodium falciparum was the predominant species (98.0%); the least prevalent was Plasmodium malariae (2.0%). In male donors the prevalence of malaria parasitemia was 62.0%; the prevalence in female donors was 62.5%. Among paid donors the malaria parasitemia rate was 82.3%, compared with 22.4% in volunteer donors. Donors who reported their occupation as businessperson (individual who engages in commercial trade, mostly outdoors in a market environment) had the highest prevalence, at 94.3%; students had the lowest prevalence, at 31.9%.

Conclusion: A high percentage of blood donors in Jos, Nigeria, actually harbor malaria, which is cause for concern and more careful donor screening by healthcare professionals in that region is warranted.