Role of Sequencing the Measles Virus Hemagglutinin Gene and Hypervariable Region in the Measles Outbreak Investigations in Sweden During 2013-2014.
Authors: Harvala H, Wiman Å, Wallensten A, Zakikhany K, Englund H, Brytting M
Publication year: 2016
Journal: Journal of Infectious Diseases
Journal name in source: The Journal of infectious diseases
Journal acronym: J Infect Dis
Volume: 213
Issue: 4
First page : 592
Last page: 9
ISSN: 0022-1899
eISSN: 1537-6613
DOI: https://doi.org/10.1093/infdis/jiv434
Abstract
INTRODUCTION\nMETHODS\nRESULTS\nCONCLUSIONS\nIt is increasingly difficult to differentiate measles viruses (MeVs) relating to certain outbreaks on the basis of the nucleoprotein (N) gene sequence only, as the diversity of circulating MeV strains has decreased. We studied genomic regions that could provide better molecular discrimination between epidemiologically linked and unlinked MeV variants identified in Sweden during 2013-2014.\nThe hemagglutinin (H) gene and hypervariable region between the fusion and matrix genes (MF-HVR) from 53 MeV-positive samples were amplified and sequenced. Data on phylogenetic clustering of MeVs on the basis of N, H, and MF-HVR sequences were compared to epidemiological data.\nMeVs were genotyped: 27 were B3, and 26 were D8. One genotype B3 cluster based on the N gene sequence contained epidemiologically unrelated viruses from 4 outbreaks, whereas analysis of H and MF-HVR sequences separated them into phylogenetic clusters consistent with the epidemiological data. Similarly, the single cluster of viruses with a genotype D8 N gene could be divided into the 5 outbreak groups on the basis of the phylogeny of MF-HVR sequences.\nA detailed picture of MeV circulation with more-defined links between outbreaks was obtained by sequencing the H gene and MF-HVR. Further identification and better genetic characterization of MeVs internationally is essential in identifying sources and routes of MeV spread within and beyond Europe in the elimination end game.
INTRODUCTION\nMETHODS\nRESULTS\nCONCLUSIONS\nIt is increasingly difficult to differentiate measles viruses (MeVs) relating to certain outbreaks on the basis of the nucleoprotein (N) gene sequence only, as the diversity of circulating MeV strains has decreased. We studied genomic regions that could provide better molecular discrimination between epidemiologically linked and unlinked MeV variants identified in Sweden during 2013-2014.\nThe hemagglutinin (H) gene and hypervariable region between the fusion and matrix genes (MF-HVR) from 53 MeV-positive samples were amplified and sequenced. Data on phylogenetic clustering of MeVs on the basis of N, H, and MF-HVR sequences were compared to epidemiological data.\nMeVs were genotyped: 27 were B3, and 26 were D8. One genotype B3 cluster based on the N gene sequence contained epidemiologically unrelated viruses from 4 outbreaks, whereas analysis of H and MF-HVR sequences separated them into phylogenetic clusters consistent with the epidemiological data. Similarly, the single cluster of viruses with a genotype D8 N gene could be divided into the 5 outbreak groups on the basis of the phylogeny of MF-HVR sequences.\nA detailed picture of MeV circulation with more-defined links between outbreaks was obtained by sequencing the H gene and MF-HVR. Further identification and better genetic characterization of MeVs internationally is essential in identifying sources and routes of MeV spread within and beyond Europe in the elimination end game.