A possible case of a mysterious form of child hepatitis has been found for the first time in Japan, the health ministry has said. Cases so far have mostly been reported in Europe.

The health ministry said Monday that the patient is 16 years old or younger but has not revealed their age, address or sex. The patient, who has been hospitalized, corresponds to the working definition of a “probable case" of the acute, severe hepatitis provided by the World Health Organization, the ministry said.

According to the WHO, 169 cases of hepatitis of unknown origin, with one death, had been confirmed in 12 countries as of Thursday, with ages ranging from 1 month to 16 years old. Reported symptoms include abdominal pain, diarrhea, vomiting, yellowing of the skin (jaundice) and elevated liver enzyme levels.