Clinical and genetic characterization of measles viruses isolated from adult patients in Shanghai in 2006

BackgroundIn recent years there has been an increase in adult measles cases in Shanghai, and an outbreak occurred in 2005. Although there have been many studies analyzing the genotype of measles virus from pediatric patients in various parts of China, there is little information on the clinical findings and genetic makeup of adult measles.ObjectivesClinical information and phylogenetic analysis of adult measles infection in Shanghai.Study designBlood, urine, throat swabs, and clinical information were collected from adult measles patients reporting to three major hospitals in Shanghai. Measles virus was isolated in Vero-SLAM cells. The C-terminus of the N gene of the isolates was sequenced and analyzed with reference to sequences obtained from GenBank.ResultsMore than half of the patients developed severe clinical symptoms. None of the patients knew their measles vaccination history. All measles virus isolates had the same amino acid substitutions as the two standard H1a measles strains at position 484 and were classified as H1a genotype and could be further divided into three small clusters.ConclusionsThe genotype of the predominant measles virus causing disease in adults in Shanghai is H1a.