Rubella among the Amish: resurgent disease in a highly susceptible community.

Although the Amish make up less than 0.05% of the United States population, nearly all rubella reported in the United States in 1991 occurred in this population. In early 1991 a large rubella outbreak in a Tennessee Amish community that had experienced no rubella for 17 years afforded an opportunity to describe the epidemiology of rubella in this unique population. Structured interviews were conducted with 54 Amish families. Of 383 persons in the sample 85 (22%) had rubella. Illnesses were mild; 16% of cases lacked fever and 20% of cases reported no symptoms except rash. Children < 17 years of age were 7 times more likely than older individuals to be affected (77 of 214 vs. 8 of 165). All pregnant women in the community were > 20 years of age; none developed rubella. No congenital rubella syndrome was recognized. Although rubella is increasingly a disease of adolescents and young adults, in this outbreak, rubella was again a childhood disease. Illness in this community-based investigation was mild; rubella may be difficult to diagnose and report. Immunity after remote natural infection was durable since the community's last outbreak. Pregnant women probably were protected by the age distribution of immunity; this age distribution may not occur in other Amish populations. If preventable morbidity from rubella and other vaccine preventable diseases is to be avoided in this group, increased attention should be directed to encouraging vaccinations among Amish persons.