Measles Cases in Japan Rise to 299 This Year, Surpassing Last Year’s Total

Japan is experiencing a significant increase in measles cases, with health officials reporting 299 cases as of early April 2026, according to a preliminary report from the Japan Institute for Health Security. This figure already exceeds the total of 265 cases recorded for all of 2025 and marks a sharp rise in infections nationwide.

The surge is particularly notable in Tokyo, which has reported the highest number of cases by prefecture at 108, followed by Kanagawa (31), Kagoshima (28) and Chiba and Aichi (23 each). During the week through April 12, 56 new cases were reported—the highest weekly total so far this year.

Measles is a highly contagious viral illness that spreads through respiratory droplets when an infected person breathes, coughs, or sneezes. Symptoms typically include high fever, cough, runny nose, red eyes, and a characteristic rash that spreads from the face to the rest of the body. In some cases, measles can lead to serious complications such as pneumonia, encephalitis, or even death, particularly in young children and those with weakened immune systems.

Health officials emphasize that vaccination remains the most effective way to prevent measles. The measles vaccine is administered in two doses—first at age one and again before school entry—and is available at no cost through public health programs. Despite this, data shows that 74% of those infected this year had either received only one dose, were unvaccinated, or had an unknown vaccination history.

The Japan Institute for Health Security and the Ministry of Health, Labour and Welfare are urging the public to check their vaccination status and seek medical advice promptly if symptoms develop. Individuals experiencing fever or rash are advised to contact a healthcare provider by phone before visiting a clinic to avoid spreading the virus in waiting rooms or on public transportation.

Although Japan has made progress in controlling measles over the past decade, the current uptick underscores the importance of maintaining high vaccination coverage. The highest annual total in the last ten years was 744 cases in 2019, and health authorities are working to prevent a return to such levels through timely public health messaging and outreach.

As the situation continues to be monitored, officials stress that early detection, isolation of suspected cases, and widespread immunization are key to curbing further transmission and protecting community health.