Clustering of haemagglutinin gene sequences of measles viruses isolated in the Gambia

Partial nucleotide sequences of the haemagglutinin (H) gene of 18 measles viruses isolated in the Gambia during 1994 and 1995 show a high degree of homology (>98.5%) when compared with each other. These sequences form a cluster distinct from measles viruses isolated from other geographic regions and from the sequences of vaccine strains and two isolates from the Gambia from earlier years. Despite the low level of genetic heterogeneity observed, a common feature of the Gambian isolates is the prescence of three nucleotide changes (at positions 7963, 8649 and 8653) not observed in isolates from other locations.