Prevalence of blood-borne viral infections (cytomegalovirus, human herpesvirus-6, human herpesvirus-7, human herpesvirus-8, human T-cell lymphotropicvirus-I/II, human retrovirus-5) among blood donors in Latvia

The identification of blood-borne viral infections is important in transfus ion medicine. The aim of this study was to evaluate the prevalence of human herpesvirus (HHV) [cytomegalovirus (CMV), HHV-6, HHV-7 HHV-8] and human re trovirus (HRV) (human T-cell lymphotropic virus (HTLV)-I/II, HRV-5) infecti ons among apparently healthy Latvian blood donors. DNA extracted from perip heral blood leukocytes (PBL) of 150 individuals was tested for herpesviruse s by sensitive polymerase chain reaction (PCR) technique. None of the blood donors was positive for HHV-8 infection, while the incidence of latent P-h erpesvirus infections was high: single infection by CMV, HHV-6, and HHV-7 w as detected in 2.6%, 8.0%. and 43.3% of blood donors., respectively. Simult aneous dual and triple infections of these viruses were observed in 28.0% a nd 4.7% of individuals, respectively. Active infection by CMV and HHV-6 was not found. but HHV-7 DNA was present in plasma of 10.6% of the blood donor s. While all blood donors were HTLV-II and HRV-5 negative., 4.6% of HTLV-I seronegative blood donors were positive for the HTLV-I tax gene. although n one of them harbored sequences for structural genes of the provirus. Based on our results, we conclude that monitoring of beta -herpesvirus infe ctions in blood donors can be important in cases of transfusions to immunoc ompromised persons. HHV-8. as well as the retroviruses HTLV-II and HRV-5, w ere not found in blood of Latvian blood donors. More investigations are req uired to explain the presence of the HTLV-I tax sequence in seronegative bl ood donors.