A new quantitative PCR for human parvovirus B19 genotypes.

Parvovirus B19 (B19V) is a minute ssDNA virus associated with a wide range of diseases from childhood erythema to fetal death. After primary infection, the viral genomes persist lifelong in solid tissues of most types. Quantification of the viral DNA is important in the timing of primary infection, assessment of tissue persistence and screening of blood donor plasma. In this study, we present a new PCR assay for detection and quantification as well as for differentiation of all three B19V genotypes. A new B19V qPCR was designed to target a 154-bp region of the NS1 area. Serum, plasma and solid tissue samples were suitable for testing in the assay. The WHO International Reference Panel for Parvovirus B19 Genotypes was utilized to validate the assay for detection of different genotypes of B19V in clinical material. Each panel member yielded, by the new qPCR, a quantity similar to the one reported by National Institute for Biological Standards and Control (NIBSC). The qPCR was specific for B19V and amplified and quantified all three genotypes with detection sensitivities of ≤10 copies/reaction. The differentiation of B19V genotypes was performed by Sanger sequencing of the amplified products.