The number of patients confirmed to have contracted rubella since the start of the year topped 10,000 in early June, far exceeding the total for the whole of 2012, the National Institute of Infectious Diseases said Tuesday.
A total of 517 people were confirmed to have symptoms of the disease after being infected by the virus between June 3 and 9, bringing the tally so far this year to 10,102 cases, compared with 2,392 for the whole of 2012, the institute said.
By prefecture, Osaka had the largest number of new infections — 129 — during the most recent week, followed by 82 in Tokyo, indicating that the focus of the disease's spread may shift to western prefectures, the institute said.
The weekly tally of new patients has been high at around 800 over the past few weeks, but it is not clear whether the spread of the disease has started to tail off, the institute added.