抄録
A large rubella outbreak has been observed since June 2012 in Tokyo, Japan, and rapid growth of congenital rubella syndrome (CRS) cases have also been reported in Japan since October 2012. All of the clinically diagnosed and laboratory-confirmed rubella cases reported in Tokyo from January 2012 to December 2013 and of the laboratory-confirmed CRS cases from January 2012 to March 2014 were analysed. A total of 4,116 rubella cases were reported in Tokyo. About three quarters were male (n = 3,176; 77.2%); the highest number of cases in male occurred at aged 35–39-year-old and in female 20–24-year-old. Complications included arthralgia/arthritis (19.4%), thrombocytopenic purpura (0.5%), hepatic dysfunction (0.3%) and encephalitis (0.1%). The circulating rubella virus in Tokyo was genotype 2B. The most possible site of transmission was at workplaces. As a consequence of the rubella epidemic, a total of 16 CRS cases were reported in Tokyo from March 2013 to February 2014. Domestic infection of rubella was proven for all mothers of 16 cases. This situation suggests that Japan still is on the way to the rubella elimination.
