Genetic variants of parvovirus B19 identified in the United Kingdom: Implications for diagnostic testing

BackgroundDiscrepant results in diagnostic parvovirus B19 PCR assays have been observed with strains showing nucleotide sequence variation.Objectives and study designTo perform phylogenetic analysis on two parvovirus B19 strains that gave discrepant PCR results.ResultsOne strain was found to be genotype 2; the second strain was genotype 3.ConclusionsParvovirus B19 genotypes 2 and 3 strains were identified in diagnostic samples of UK origin following the investigation of discrepant PCR results. More structured investigations are needed to estimate the prevalence of these variants. In the meantime, diagnostic PCR results should be interpreted cautiously when they are at variance with serological testing. Manufacturers of PCR kits for the detection of B19 sequences will need to consider re-designing their primers.