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CDC: COVID-19 Can Spread 13 Feet, Travel on Shoes

Coronavirus

April 14, 2020 - The novel coronavirus can travel 13 feet through the air and be carried around on people’s shoes, according to a new report from the CDC.

The airborne distance is more than twice the recommended social distancing guidelines to stay 6 feet away from others. The new research, published in the agency’s Emerging Infectious Diseases journal, may help to explain how the virus is being spread.

The study team tested air and surface samples at Huoshenshan Hospital in Wuhan, China, to detect the distribution of the coronavirus that causes the disease known as COVID-19. They found that the contamination was on floors, computer mice, trash cans, sickbed handrails and doorknobs, and it was higher in intensive care units than in the general hospital wards.

“The extremely fast transmission capability of [coronavirus] has aroused concern about its various transmission routes,” according to the report, which was conducted by the Academy of Military Medical Sciences in Beijing.

Between Feb. 19 and March 2, the study authors collected samples by swabbing objects that might be contaminated. They also sampled indoor air and the air outlets. The intensive care unit had 15 patients with severe disease, and the general ward had 25 patients with mild disease.

Overall, they reported, the samples that tested positive for the virus were concentrated in the contaminated areas, particularly in the ICU. The floor swabs also had a high rate of positive tests, potentially due to virus droplets falling on the ground. Half of the ICU staff’s shoes also tested positive.

“In addition, as medical staff walk around the ward, the virus can be tracked all over the floor, as indicated by the 100% rate of positivity from the floor in the pharmacy, where there were no patients,” the authors wrote.

While testing the aerosol transmission, the research team found positive test results for 35% of tests in the ICU and 12.5% of tests in the general ward. The samples varied by the location as well. About 44% of tests in patients’ rooms were positive, followed by about 36% near air outlets. One of 8 tests in the doctors’ office area was positive.

The maximum transmission distance could be 4 meters, the authors wrote, which is about 13 feet.

The results could imply a “potentially high infection risk” for medical staff and their close contacts, the research team concluded. Stricter measures should be taken, particularly for those working in intensive care wards.

The CDC recommends 6 feet for social distancing, and the World Health Organization recommends 3 feet.