Molecular epidemiology of human respiratory syncytial virus

Human respiratory syncytial virus (HuRSV) is the major viral cause of severe lower respiratory tract disease in babies and infants with epidemics occurring annually in the winter in temperate climates. Analysis of the antigenic and genetic variability of HuRSV isolates has shown that there are two groups of the virus and that each group can be further subdivided into a number of genotypes in which the attachment protein shows the greatest variability together with progressive change. Epidemics are made up of multiple genotypes whose proportions vary from year to year. The various genotypes cocirculate with very similar viruses distributed world-wide.