Multiple Sclerosis Clustering in a Small Massachusetts Community, with Possible Common Exposure 23 Years before Onset

Abstract

PREVALENCE surveys over the past 50 years have provided data of varying validity concerning the frequency of multiple sclerosis throughout the world. Of interest are the reports of high rates of multiple sclerosis in areas of small population (Table 1). As McAlpine, Lumsden and Acheson4 point out, these rates are derived from small numbers of cases, and the sampling error tends to be large. Although investigations in small populations are limited, they can provide clues on which etiologic hypotheses may be based.Mansfield, Massachusetts, is an industrial-residential town of 10,000 persons, located 45 km from Boston. The suggestion by a . . .