This file photo taken on Jan. 24, 2020 shows a traditional Japanese school lunch. (Mainichi/Manabu Matsuda)

A lunch lady in her 50s responsible for delivering meals to classrooms at an elementary school in Ebetsu, Hokkaido, northern Japan, has tested positive for the new coronavirus, the city education board announced on Feb. 23.

The school building will be disinfected before classes resume on Feb. 25. None of the students have reportedly complained of feeling unwell.

According to the Ebetsu Municipal Board of Education, the infected woman is responsible for dividing up the lunch dishes in the school food service room and bringing the meals up to the doors of each classroom for the second to fourth grades, comprising 194 students. She wore a face mask, gloves and a white coat during work.

The woman complained of a sore throat on Feb. 13 but worked the next day, and did not go to see a doctor until Feb. 15. Her two co-workers have been put on leave until the end of this month as a precautionary measure.

On Feb. 23, a total of 12 people in Hokkaido, Chiba Prefecture east of Tokyo, and the central Japan prefecture of Aichi tested positive for the novel coronavirus.

In Hokkaido, nine people in their 20s to 80s have been confirmed infected. According to the prefectural government, a student in her 20s is in serious condition and is on a ventilator.

A man in his 40s who lives in Chiba and works in Tokyo was also confirmed to have the virus. He began suffering from joint and muscle pain on Feb. 12 but went ahead with business trips to Hiroshima and Gifu prefectures, in western and central Japan, respectively. He traveled by shinkansen bullet train and occasionally by rental car during the trips, and developed a cough and fatigue on Feb. 14.

A woman and a man in their 70s in Nagoya who tested positive for coronavirus were confirmed to have been in the same building as a woman in her 60s infected with the new virus.

(Japanese original by Chie Yamashita, Hokkaido News Department, Yuki Machino, Chiba Bureau, and Naoto Takeda, Nagoya News Center)