MOLECULAR EPIDEMIOLOGY OF MEASLES-VIRUS - IDENTIFICATION OF PATHWAYS OF TRANSMISSION AND IMPLICATIONS FOR MEASLES ELIMINATION

The nucleotide sequences of either the hemagglutinin or nucleoprotein genes from wild type measles viruses isolated in the United States bet ween 1989 and 1992 differed by <0.5%. This suggests that the majority of viruses associated with resurgence of measles in the United States belonged to a single indigenous genotype, In contrast, wild type virus es isolated from sporadic outbreaks of measles in the United States du ring 1994 were genetically heterogeneous, These viruses were more clos ely related to wild type viruses previously circulating in Europe, Afr ica, or Japan and were epidemiologically linked to importations or no known source, In addition to demonstrating the utility of genetic anal ysis in understanding the epidemiology of measles, these data suggest that the transmission of the indigenous virus was interrupted after th e 1989-1992 epidemic, Measures to further reduce the incidence of meas les in the United States should include efforts to control importation and subsequent spread of measles.