Researchers on a Health, Labor and Welfare Ministry team tasked with countermeasures against clusters of coronavirus infections found that young people introduced the virus first in many cluster cases.
The finding was reported in a medical journal of the U.S. Centers for Disease Control and Prevention. As there were cases in which people spread the virus before developing COVID-19, the team said it is important for everyone, even if they have no symptoms suggesting an infection, to take measures such as wearing a face mask and keeping a distance from other people.
Prof. Hitoshi Oshitani of Tohoku University, Project Assistant Professor Yuki Furuse of Kyoto University and others researched the occurrence of cluster cases involving five or more patients among 3,184 people confirmed to be infected from Jan. 15 to April 4 in Japan.
The team found 61 cluster cases. By setting, the highest number at 18 cases occurred at medical facilities, followed 10 each at care facilities and restaurants, eight at workplaces and seven at music-related events.
Researchers identified the people who introduced the virus first in 22 of the cases. In half of the cases, six people in their 20s and five in their 30s were the source of the cluster. They also found the date on which people first transmitted the infection to others in 16 cases. Among those, there were five cases in which a person spread the infection one day before developing the disease, three cases in which they did so two days before developing the disease, and one case in which they did so three days before developing the disease.
Read more from The Japan News at https://japannews.yomiuri.co.jp/
