Nosocomial rubella--consequences of an outbreak and efficacy of a mandatory immunization program.

An outbreak of rubella in a large metropolitan hospital is described. Nineteen cases among employees and three secondary cases in family members occurred. Nosocomial cases occurred among the 3,900 employees of an adult medical-surgical unit where a voluntary program of rubella immunization was in effect. No cases occurred among the 1,400 employees of the women's and pediatric units with mandatory policies, despite interfacility and community exposure. Ten pregnant women were among the 377 contacts of the cases. Five were sero-negative to rubella. Two who developed clinical rubella, one asymptomatic sero-conversion and one other, all elected to terminate their pregnancies. The remaining woman, exposed in her third trimester delivered a normal infant. We conclude a policy requiring new employees to be rubella immune is more effective in preventing nosocomial rubella than a voluntary program and is desirable in view of the potential consequences of an outbreak to pregnant employees.