Summary and conclusions: measles elimination meeting, 16-17 March 2000
Katz, S.L.; Hinman, A.R.
Journal of Infectious Diseases 189 Suppl. 1: S43-S47
2004
ISSN/ISBN: 0022-1899 PMID: 15106088 DOI: 10.1086/377696Document Number: 514907
The status of measles elimination is best summarized by evaluation of the effective reproduction number R; maintaining R<1 is necessary and sufficient to achieve elimination. Previously described methods for estimating R from the sizes and durations of chains of measles transmission and the proportion of cases imported were applied to the measles data reported for the United States in 1997-1999. These comprised 338 cases, forming 165 chains of transmission, of which 43 had >1 case. One hundred seven cases were classified as importations. All 3 methods suggested that R was in the range 0.6-0.7. Results were not sensitive to the minimum size and duration of outbreak considered (so long as single-case chains were excluded) or to exclusion of chains without a known imported source. These results demonstrate that susceptibility to measles was beneath the epidemic threshold and that endemic transmission was eliminated.