DESCRIBING THE PREVALENCE OF ASYMPTOMATIC MALARIA AND VIRAL INFECTIONS AMONG BLOOD DONORS IN COASTAL KENYA

Abstract

Blood transfusion is a practice that has saved millions of lives of patients with severe anemia. Although blood transfusion is life saving, the practice poses a great threat to the health of the recipient due to transmission of blood borne infections. WHO‘s recommendation of mandatory screening for Transfusion Transmissible Infections (TTIs) namely Human Immunodeficiency Virus (HIV), syphillis, hepatitis B, and C has greatly lowered the risk of their transmission through transfusion. Recent studies have, however, highlighted a number of clinically important arthropod-borne viruses like dengue and chikungunya virus among others; as well as human parvovirus B19 and malaria that are transfusion transmissible and therefore pose a risk to blood safety. Despite the high levels of transmission in sSA, and the evidence of transmission both in sSA, these pathogens do not form part of the pathogen panel that undergo routine screening by blood transfusion services both in Kenya and sSA at large. The present study aimed to determine the prevalence of malaria, dengue, chikungunya and human parvovirus B19 among healthy blood donors at the Kenyan coast. The study adopted a cross-sectional design that involved asymptomatic voluntary blood donors presenting at donor drives in three selected counties along the Kenyan coast. Malaria diagnosis was done using Real-time polymerase chain reaction (RT-PCR) in addition to microscopy and rapid diagnostic test (RDT). RT-PCR was used to screen for both sexual and asexual Plasmodium falciparum stages targeting the Pfs 18 and Pfs 25 genes specifically expressed in asexual and sexual stages respectively. Dengue and Chikungunya virus screening was done using the Pan-flavivirus and Pan-Alphavirus assay respectively which both target the RNA polymerase of the virus using RNA extracted from 100 µl of a blood sample. Screening for Parvovirus B19 was also done by RT-PCR targeting the DNA of the virus extracted from 300 µl of a blood sample. vi We found an overall prevalence of malaria of 0.79%. Parasitaemia by microscopy ranged between 80-3560 parasites/µL. 0.8% (N=9) of the donors were positive for Parvovirus B19 with viremia ranging between 126-121,395 viral copies per mL of blood. None of the blood donors was positive for chikungunya and dengue virus. The detection of malaria and parvovirus B19 among blood donors in coast Kenya has added to the evidence on the growing threat posed by emerging transfusion transmitted infections to blood safety in Kenya. Although the prevalence of these infections was low, the underlying risk of transfusing a single infected pint is immense.