After a Period of Quiet, Surge in Measles Cases Puts Japanese Health Authorities on High Alert

139 Cases This Year, Fourfold Increase Over Last Year
Local Transmission Suspected After Imported Cases

Measles, which had largely disappeared from Japan for a period, is now showing signs of resurgence, putting health authorities on high alert. The number of patients this year has already surpassed four times the number recorded during the same period last year, and cases are being identified even among individuals with no history of overseas travel, indicating a broader spread.

Measles. Photo to assist in understanding the article. Getty Images Bank

According to Fuji News Network (FNN) and Kyodo News on March 24, the National Institute of Infectious Diseases (NIID) in Japan reported that as of March 15, there had been 139 confirmed cases of measles this year. This is an increase of 32 cases in just one week, and more than four times higher than the 32 cases reported during the same period last year. It is the highest number since the outbreak of COVID-19.

Japan received "measles elimination" certification from the World Health Organization (WHO) in 2015, but the situation has changed recently as imported cases have increased. The number of measles patients in Japan soared to around 700 in 2019, dropped to fewer than 10 during the COVID-19 pandemic, but has begun to rise again. In fact, there were 265 cases last year, and the pace of increase is even faster this year.

Notably, infections are now being confirmed even among people with no history of overseas travel. Experts believe that the virus, brought in by foreign visitors or Japanese nationals returning from abroad, has started to spread more widely within Japan.

Measles is an extremely contagious disease that is transmitted through the air and causes symptoms such as fever, rash, and cough. If a person without immunity comes into contact with a patient, the infection rate is known to be over 90%. In severe cases, it can lead to encephalitis or even death.

The Japanese Ministry of Health, Labour and Welfare has recommended, "Before leaving the country, be sure to check your vaccination history and complete any necessary vaccinations, and after returning, closely monitor your health for two weeks."

Meanwhile, the spread of measles is not limited to Japan. Although widespread vaccination had sharply reduced cases for decades and measles was considered a "developing country disease," a resurgence is now being seen in major countries, including the United States. In the U.S., there were 2,274 confirmed cases last year, the highest in about 30 years. The upward trend continues this year, with hundreds of cases already reported. Canada has also seen ongoing cases, and in November last year, it lost its "measles elimination" status from the World Health Organization. To maintain this status, a country must have no domestic cases for at least 12 consecutive months.

This content was produced with the assistance of AI translation services.