Distribution of varicella-zoster virus (VZV) wild-type genotypes in northern and southern Europe: evidence for high conservation of circulating genotypes

Abstract

Phylogenetic analysis of 19 complete VZV genomic sequences resolves wild-type strains into 5 genotypes (E1, E2, J, M1, and M2). Complete sequences for M3 and M4 strains are unavailabl.

Sequence analysis of VZV isolates identified both shared and specific markers for every genotype and validated a unified VZV genotyping strategy. No evidence for intra-genotypic recombination was observed.

Five of seven VZV genotypes were reliably discriminated using only four single nucleotide polymorphisms (SNP) present in ORF22, and the E1 and E2 genotypes were resolved using SNP located in ORF21, ORF22 or ORF50. Sequence analysis of 342 clinical varicella and zoster specimens from 18 European countries identified the following distribution of VZV genotypes: E1, 221 (65%); E2, 87 (25%); M1, 20 (6%); M2, 3 (1%); M4, 11 (3%).

No M3 or J strains were observed