The number of measles cases confirmed in Japan this year has reached 523.

Although the pace of increase has slowed somewhat, the Ministry of Health, Labor and Welfare says the situation cannot be taken lightly and urging continued vigilance.

According to the ministry, 11 new measles cases were reported nationwide during the week ending May 31.

The cumulative total for 2026 has now reached 523 cases, approximately four times higher than during the same period last year.

Of the 11 newly reported cases, seven were recorded in Tokyo, the highest among prefectures.

Two cases were reported in Saitama Prefecture, while Kanagawa and Ibaraki prefectures each reported one case.

The ministry says no large-scale outbreaks have been reported.

However, measles is highly contagious and despite a slowdown in the rate of increase, health officials say the disease remains a serious concern.

The ministry says it will continue to closely monitor the situation and is urging people to confirm their vaccination status.

Officials also advise anyone who develop symptoms to contact a medical institution in advance before seeking treatment.