Mumps in the region of Rijeka, Croatia.

Compulsory vaccination against mumps at 15 months of age in the region of Rijeka, Croatia (340,467 inhabitants in 1990) started in 1976. The incidence and distribution of reported mumps cases during the period from 1976 to 1990 are presented. Two epidemics were reported during this period. The first was in 1977 with an incidence of 434.7 per 100,000 inhabitants. The second lasted throughout 1981 (incidence 432.5) and 1982 (incidence 552.1). An eight-year period, 1983-1990, followed with a low reported incidence. The highest incidence was among 5 to 9-year olds during the first post-vaccination period (1976-1982), while it shifted to 15 to 19-year olds during the second post-vaccination period (1983-1990). Mumps remains a spring-time disease with highest incidence in April. Registered cases were more frequent in males (55%) than in females (45%).