There is a possibility that sumo wrestlers are easily infected with the new coronavirus, and when infected, they are likely to become seriously ill. The reasons for being susceptible to infection are that they live in groups in sumo rooms, collide and practice, and eat together. Breathing becomes intense during collision practices, and in such situations a large amount of droplets are generated from the mouth. The droplets will easily reach their opponents. In fact, clusters have been reported in various sports(1). During mealtime, several wrestlers eat chanko twice, day and night. Chanko is a Japanese stew commonly eaten in vast quantity by sumo wrestlers as part of a weight-gain diet. They remove the masks when eating it. If they chat there, a large amount of droplets will fly around. This is also the situation where the new coronavirus may spread.
Of course, nowadays, in the sumo room, infection control against the new coronavirus are progressing, and such a situation will be improved further. However, clusters are likely to occur if there is a situation that meets the definition of a close contact, “less than 1 m and talk for more than 15 minutes without wearing a mask”.
Sumo wrestlers are considered to be at high risk of becoming severe conditions when infected with the new coronavirus. Risk factors include aging, renal dysfunction, diabetes, malignant disease, chronic kidney disease, chronic obstructive pulmonary disease, immunodeficiency due to solid organ transplantation, obesity (BMI ≥ 30), and serious cardiovascular disease (Heart failure, coronary artery disease, cardiomyopathy), smoking, etc. Regarding obesity, it is known that even “BMI = 25 to 30 ” can be a serious factor. They are obese and may have diabetes. If they have two of these risk factors, they are more likely to become more severe. Also, there is a risk of severe pneumonia and pulmonary embolus.
So what should they do? It’s best to wear a mask in each room, but it can be difficult in practice. Therefore, always try to keep at least 1 m of physical distance. This will prevent the droplets from reaching to others and reduce the frequency of body-to-body contacts. Of course, conversations and screaming loudly are contraindicated. As for meals, chanko should be served on a small plate and whenever possible, it’s best to eat separately. There is also a way to face the wall and eat without talking when eating. Of course, if you experience fatigue, fever, cough, taste / smell disorders, shortness of breath, etc., they should seek medical attention immediately. Since they are at high risk of becoming seriously ill, watching their condition for several days is a dangerous response.
（Author: Assistant Director of Hamamatsu Medical Center, Director of Department of Infectious Diseases, Director of Hygiene Management Office, Kunio Yano）
〔Reference〕
（1）Atrubin D, et al：An outbreak of COVID-19 associated with a recreational hockey game — Florida, June 2020.
https://www.cdc.gov/mmwr/volumes/69/wr/pdfs/mm6941a4-H.pdf
