Seroprevalence, molecular epidemiology and quantitation of parvovirus B19 DNA levels in Iranian blood donors.

Human parvovirus B19 (B19) infection is common among blood donors, and healthy blood donors can transmit virus via transfusion. Due to resistance of B19 to viral inactivation methods, there is a potential concern regarding transfusion safety in blood products. We aimed to determine the seroprevalence, molecular epidemiology, and quantitation of B19 DNA levels in blood donors in Tehran, Iran. A total of 500 blood donors from Blood Transfusion Research Center were studied. ELISA was used for detection of B19 IgG and IgM and nested PCR was carried out for detection of B19 DNA. PCR products were subjected to direct sequencing. B19 viral load was determined by real time PCR. B19 IgG, IgM, and DNA were detected in 27.6, 2.6, and 1.2% of donors respectively. Ten samples (2%) were positive for both antibodies while in four cases (0.8%), B19 IgG and DNA detected simultaneously. One case had B19 IgM, IgG, and viremia concurrently. The titers of B19 DNA in four of six donors were more than 106  IU/mL (high level viremia) and all four cases had IgG simultaneously. All B19 isolates categorized in genotype 1A. Our findings indicated that prevalence of B19 DNA in Iranian blood donors was comparable with previous studies throughout the world. High level B19 viremia found in 0.8% of our donors and all viremic donors revealed neutralizing B19 antibody. Therefore implementation of a B19 screening test for each volunteer blood donor does not appear to be necessary but B19 testing for plasma-derived products seems important in Iranian donors.