CUMULATIVE AUTHOR INDEX FOR MUTREV 2001

Abstract

A nationwide measles outbreak occurred in Vietnam between 2013 and 2014.To provide an overview on the 2013–2014 measles outbreak in northern Vietnam using epidemiological and molecular analysis of the measles virus (MeV).Epidemiological information was collected from all suspected cases of measles/rubella. Serum and/or throat swabs were collected for laboratory confirmation of measles. MeV genomes were detected and sequenced for phylogenetic analysis.A total of 9577 confirmed measles cases were reported in northern Vietnam with an incidence rate of 116.4/1,000,000 population. Of these, approximately 76.3% had unvaccinated or unknown vaccination history and 55.7% were under five years old. The outbreak started in a minority population from the mountainous area bordering Lao PDR and China and exploded in high-density population areas. Molecular analysis of MeV revealed co-circulation of genotypes H1 and D8, with H1 as the predominant strain, and divided into two clusters: cluster 1, sharing high similarity with those detected in China and Lao PDR, and cluster 2, circulating locally with unidentified origin. The minor D8 strains belonged to the D8-Frankfurt cluster.The outbreak originated in and spread from a population with limited access to vaccines. Molecular analysis revealed co-circulation of MeVs with three different origins during the outbreak. This is the first report to provide an overview of the 2013–2014 measles outbreak in northern Vietnam, demonstrating the need for vaccination strategies against measles that are tailored to local conditions with enhanced molecular surveillance to achieve measles elimination.