Haemoparasites of blood donors in Calabar

The study of haemoparasites in our blood donors revealed the following parasite prevalences: microfilaria (mf) of Loa loa (1.3%); Dipetalonema perstans (15.6%); Loa loa and D. perstans (0.2%), Plasmodium falciparum (3.3%), Plasmodium malariae (1.0%) and a mixture of P. falciparum and P. malariae (0.2%). No trypanosomes were observed in the 480 blood samples screened. There were more cases of D. perstans infection in the 24-30 year age group, indicating their increased exposure frequencies. Matching of ABO blood group and mf infection rates shows that the O blood group has a higher prevalence rate with regard to D. perstans than Loa loa. The B blood group, however, had the highest cumulative % of mf infection (23.4%), but these values are consistent with the preponderance of the various blood groups in the study population. Commercial donors, most of whom come from the less affluent social classes, had higher prevalence rates of mf. It is recommended that blood be properly screened for mf before donation for transfusion. Recipients of infected blood should be followed up so that any consequent infection would be treated immediately.