Research has suggested that if a medical practitioner who treats patients with coronavirus (COVID-19) is not wearing a N95 mask, they are 465 times more likely to be infected with the virus than wearing a mask.
According to the latest issue of the <Journal of Hospital Infection> on March 14, the research team at Zhongnan Hospital in Wuhan, China, 493 analyzed the infection risks of medical staffs (135 doctors, 358 nurses) participated in the treatment of COVID-19 patients from January 2 to 22.1 In this study, 278 medical staff (56 doctors, 222 nurses) wore N95 protective masks while working in a quarantine area with a high risk of infection. On the other hand, 215 other medical staff (79 doctors, 136 nurses) remained in the non-isolated area, which is considered to have a relatively low risk of infection, and did not wear any masks. The reason for the large number of medical staff who did not wear masks at the time was that the risk of COVID-19 was not initially identified. Patients with N95 masks were more than 8 times more likely to contact patients without masks.
The researchers compared COVID-19 infection in both groups. As a result, medical personnel wearing N95 masks did not experience any infection during the investigation period despite frequent contact with COVID-19 patients. On the other hand, in the group with few patient contacts and no masks, 10 medical staff were infected.
Based on the results of the analysis, the researchers estimated that the risk of COVID-19 infection in the group without the N95 mask was 464.8 times higher. The researchers also added that the link between N95 mask wearing and COVID-19 infection was observed in two other hospitals in Wuhan. In the paper, the researchers found that medical staff wearing N95 masks often washed more hands than medical staff without masks. As a result, it was concluded that wearing N95 masks and washing hands is an effective way to prevent COVID-19 infection.
The importance of medical staff’s wearing of masks is also confirmed in a paper published by the University of New South Wales (UNSW) in Australia and the Center for Disease Control (CDC) in June 2019 in <BMC Infectious Disease>.2 The researchers asked 148 medical staff working in high-risk wards at three hospitals in Beijing, China to wear medical masks over a period of 6 to 8 hours, and then recovered these masks to isolate the virus from the mask surface. As a result, the positive rate of the virus in all 148 masks was 10.1% (15). The virus-positive rate was 7.9 times higher than the mask worn in less than 6 hours. In addition, the positive rate of masks worn by medical staff who treated more than 25 patients a day was 5.02 times higher than the masks of medical staff who treated fewer patients.