As we live in uncertain times these days due to the presence of the novel Coronavirus amongst us; may researchers are trying to find out in what ways does this virus affects our daily work-related activities. There are numerous studies reporting the influence of COVID-19 each day; some favoring previous research while others contradict them.
The latest study by a group of researches lead by Dr. Poon at the University of Hong Kong assessed the stability of the virus at different temperatures and different surfaces, including commonly touched objects.
Results of the study
The study, published in The Lancet, reports that no infectious virus was recovered from printing and tissue papers after a 3-hour incubation; or detected from treated wood and cloth after 2 days. However, they reported the virus to be more stable on smooth surfaces. They reported the virus to be non-detectable from treated smooth surfaces on day 4 (glass and banknote) or day 7 (stainless steel and plastic).
The most striking part of their research was the detection of the virus on the outer layer of surgical / face masks even on day 7 implying that corona virus can survive on face-masks for 7 days.
This study also corroborated the fact that Corona virus can be highly stable in a favorable environment as reported by Doramalen et al. However, it can be killed by household disinfectants, bleach, or frequent hand washing with soap and water.
Dr. Malik Peiris, a member of this research team, told the Southern China Mail Post, “This is exactly why it is very important if you are wearing a surgical mask you don’t touch the outside of the mask, because you can contaminate your hands and if you touch your eyes you could be transferring the virus to your eyes.”
However, these results do “not necessarily reflect the potential to pick up the virus from casual contact” since the presence of the virus on objects and surfaces was detected using lab tools, and not fingers and hands. This study adds to an increasing body of research about the stability of the novel coronavirus and what can be done to prevent its transmission.
Looking at these results, we can also conclude that face masks cannot be re-used after 5 days as advised previously by Centre of Disease Control (CDC)- Click Here to see the CDC guidelines on Extended and reuse of N95 Masks
According to CDC, N95 respirators can function within their design specifications for 8 hours of continuous or intermittent use and it is to be strictly disposed of if used in the aerosol-generating environment. Performing hand hygiene with soap and water or an alcohol-based hand sanitizer before and after touching or adjusting the respirator (if necessary, for comfort or to maintain fit) is advised.
COVID-19 is an ongoing pandemic. It is unprecedented to see so many researchers across the globe, focus, and work on a single topic with such urgency. The result of this study is an eye-opener and helps us comprehend that the precautionary guidelines, we follow in our clinics, should be updated on a regular basis. What we follow today may not be applicable tomorrow. Therefore, the dentists are advised to do thorough research on the guidelines, from trusted sources, before starting up their clinics.
- Chin AWH et al. Stability of SARS-CoV-2 in different environmental conditions. The Lancet. Open Access Published: April 02, 2020. DOI: https://doi.org/10.1016/S2666-5247(20)30003-3
- Southern China Mail Post
- N van Doremalen, T Bushmaker, DH Morris, et al. Aerosol and surface stability of SARS-CoV-2 as compared with SARS-CoV-1 N Engl J Med (2020) published online March 17. DOI:10.1056/NEJMc2004973