A downward trend in the incidence of acquired rubella in England and Wales was reversed in 1993 when there were local outbreaks. These affected young adult males in particular, especially those living in college residences. Some spread to local antenatal populations occurred. Twenty-five confirmed infections were reported in pregnant women, most of whom were young and in their first pregnancy; this compares with totals of 12 and two in 1991 and 1992, respectively. Reports of congenital rubella have not risen since the 1993 outbreaks. Diagnosis lags behind birth, however, and further evaluation may be needed. Notifications of 14 infants, including one set of triplets, born with congenital infection since the beginning of 1991 have been received. Nine of the 12 mothers were immigrants, and three of these acquired their infection abroad. Data on antibody prevalence have revealed a large pool of susceptible males aged 10 to 25 years, which indicates that outbreaks in males would continue for some years if no action were taken. The national measles and rubella vaccination campaign in schools this month should abolish the difference in susceptibility between boys and girls up to 16 years of age and hasten progress towards the interruption of rubella transmission in the United Kingdom. Susceptibility in girls aged 13 to 14 years rose to 5.8% in 1993 from an average of 3.6% between 1986 and 1992. This suggests that the vaccination of schoolgirls has recently declined, but this component of the selective rubella vaccination programme will be discontinued after the measles and rubella campaign.(ABSTRACT TRUNCATED AT 250 WORDS)