The Novel Coronavirus disease (COVID-19) and the Culture of Taking Shoes off Indoors.

It has been six weeks since the state of emergency for the Novel Coronavirus disease (COVID-19) was declared on April 7. More than 500 new cases (positive PCR test) were reported per day in Japan in mid-April, but since the end of Golden Week, the number of new cases has gradually decreased to less than 100 per day. On the other hand, overseas, the number of new cases per day is still high: 20,000 in the United States, 15,000 in Brazil, and 10,000 in Russia as of May 17.

It has been six weeks since the state of emergency for the Novel Coronavirus disease (COVID-19) was declared on April 7. More than 500 new cases (positive PCR test) were reported per day in Japan in mid-April, but since the end of Golden Week, the number of new cases has gradually decreased to less than 100 per day. On the other hand, overseas, the number of new cases per day is still high: 20,000 in the United States, 15,000 in Brazil, and 10,000 in Russia as of May 17.

In order to prevent the spread of COVID-19, quarantine or social distancing are being taken all over the world.  In early April, both US Centers for Disease Control and Prevention (CDC) and the World Health Organization (WHO) announced their recommendations for wearing face masks to prevent transmitting infection. Until COVID-19 pandemic, few people in Europe and the United States wore masks even during the flu season. However, in just three months the situation has changed. In many countries, such as France, Germany, Italy, Czech, Austria, and Slovakia, it’s now mandatory to wear face masks while they’re out in public.

The novel coronavirus is primarily transmitted between people through respiratory droplets and contact routes. Droplet transmission is when a virus is released along with an infected person’s spit, sneeze, or cough, and another person becomes infected by inhaling the virus through their mouth or nose. In contact routes, the virus is transmitted through mucous membranes when an infected person touches an object with their hand after pressing a sneeze or cough, and then another person touches their mouth or nose with their hand after they touch the same object. It is reported that it takes for novel coronavirus on objects to lose its infectivity was 3 hours for paper, 2 days for wood and cloth, 4 days for glass, and 7 days for stainless steel and plastic. (Alex W H Chin et al: Stability of SARS-CoV-2 in different environmental conditions. The LANCET Microbe Vol 1(1) E10,May 01, 2020)

I was curious about the culture of taking shoes off indoors. In many Japanese houses, people take their shoes off at the front door when they come home from outside. Meanwhile, there are many houses overseas that do not have a shoe box at the front door, and people wear shoes indoors as well. Is there a trend in the number of  COVID-19 deaths in countries where people wear shoes indoors or take them off? Among countries with a population over one million, I listed 30 countries in order of the number of deaths per million people according to COVID-19. Western European countries tend to wear their shoes indoors, Eastern European countries conversely tend to take them off indoors. The number of deaths per population due to COVID-19 tends to be lower in Eastern European countries than in Western European countries, but it is unclear whether there is a relationship between the culture and the number of deaths. Nine of the ten countries with the highest number of deaths per million people are countries that wear shoes indoors. Although France and Germany, Italy and Austria are neighboring countries, there is a big difference in the number of deaths per million people: 411 in France compared to 95 in Germany, 521 in Italy compared to 71 in Austria. However, even in the countries categorized as “wearing shoes indoors” in this table,
some households may take off their shoes indoors or change them to indoor shoes, so I cannot say anything too strong from this table alone. A survey at a hospital specialized in novel coronavirus in Wuhan, China, reported detection of novel coronavirus on the soles of health care workers’ shoes. (Zhen-Dong Guo et al: Aerosol and Surface Distribution of Severe Acute Respiratory Syndrome Coronavirus 2 in Hospital Wards, Wuhan, China, 2020. Emerging infectious diseases. 26(7), 2020) Meanwhile I could not find any academic papers on whether the culture of taking off shoes indoors by the general public affects COVID-19 pandemic.

Johns Hopkins University      https://coronavirus.jhu.edu/map.html
Ministry of Foreign Affairs     https://www.mofa.go.jp/mofaj/area/index.html
Wikimedia Tradition of removing shoes in home https://commons.wikimedia.org/wiki/File:Tradition_of_removing_shoes_in_home.svg

In Japan, on May 4, Expert Meeting on COVID-19 recommended “New Lifestyle” such as wearing a mask, ventilate the room, washing hands frequently, and keeping distance of 2 meters apart from one another. To be accepted in “New Lifestyle” society, all our clinic staff wear masks and face shields, ventilate frequently, sanitize all areas with alcohol spray every 30 minutes, and minimize the time patients spend in the clinic. 100 years ago, when Spanish flu (influenza) hit the world, after the first epidemic subsided, followed second large epidemic a year later and third small epidemic two years later. We’re still not sure what the future holds for COVID-19 pandemic, but we would like to survive the post-coronavirus world by watching the situation not only in Japan but also in the world.

2020年05月21日