COVID-19: Surface Survival Times

The COVID-19 outbreak and subsequent pandemic has altered the way we approach the world. By learning about how long the virus that causes this disease can survive on various surfaces, divers can better understand and control their risk of infection. In this article we will examine survival of the virus on surfaces of interest to divers such as equipment, workbenches and countertops as well as the role of equipment disinfection moving forward.

Cleaning rental equipment, especially that which comes in contact with the mouth and face, has always been an important practice to ensure cleanliness and safety. Because of the highly transmissible nature of COVID-19, the act of disinfection is now more essential than ever. Experts expect that COVID-19 will continue to spread, even after resumption of business as usual, until a vaccine is developed and/or a large portion of the population has been infected. The dive community must now integrate the best available data on novel coronavirus survival times into its routine disinfection procedures.

Survival times of the virus are particularly important to consider on surfaces that cannot easily be decontaminated, such as fabrics. Research on the virus that causes COVID-19 is still developing, forcing researchers to apply knowledge about similar viruses to the novel coronavirus for answers. Because they are closely related, the coronavirus responsible for the 2003 SARS epidemic has been studied as a surrogate for the current virus. Other surrogate coronaviruses, such as human coronavirus 229E, have also been analysed.

Human coronavirus 229E was found to survive for 2-6 days on plastic, 5 days on steel, glass, PVC, silicone, TeflonTM and ceramic, up to 8 hours on latex, and 2-8 hours on aluminium¹ The SARS virus was found to survive up to 9 days on plastic, 5 days on metal, 4-5 days on paper, and 4 days on wood and glass.¹ Studies of the virus that causes COVID-19, SARS-CoV-2, found that it can survive for 2-3 days on plastic and steel, up to 4 hours on copper, up to 3 hours in aerosols (from a cough or sneeze) and 24 hours on cardboard.²

Little data exists on the survivability of SARS-CoV-2 on fabrics. Best practices are derived based on available information about infectious agents of similar structure. The novel coronavirus is an enveloped virus, which means the virion, or the form the virus takes when outside the body, is wrapped in a fatty layer to protect it during transmission. If the envelope is damaged or dries out, the virus will die. The Aujeszky's Disease virus has been shown to survive for less than one day on denim.³ However, the only similarity between that virus and SARS-CoV-2 is that both are enveloped. Experts postulate that the survival of the virus depends on porosity of the fabric. More porous fibers may trap, dry and break apart virus particles more easily. Others have said that viruses may survive for shorter times on natural fibers and longer on synthetics.⁴ Due to the lack of data about survival times on fabrics, there is unfortunately insufficient evidence to assess how long SARS-CoV-2 might survive on equipment made of synthetic fabrics, such as BCD's and wetsuits.

Definitive timeframes for the survivability of viruses on various surfaces are not collectively agreed upon at this time. For this reason, disinfection — in conjunction with additional practices such as social distancing — remains a vital part of reducing the risk of viral transmission between divers using rental equipment.

REFERENCES

1. _{Kampf G, Todt D, Pfaender S, Steinmann E. Persistence of coronaviruses on inanimate surfaces and their inactivation with biocidal agents. Journal of Hospital Infection. 2020Feb6;104(3):246–51.}
2. _{New coronavirus stable for hours on surfaces [Internet]. National Institutes of Health. U.S. Department of Health and Human Services; 2020 [cited 2020Apr17]. Available from: https://www.nih.gov/news-events/news-releases/new-coronavirus-stable-hours-surfaces}
3. _{Pirtle E, Beran G. Virus survival in the environment. Revue Scientifique et Technique de lOIE. 1991Jan;10(3):733–48.}
4. _{Leiva C. How Long Coronavirus Lives on Clothes, And How to Wash Them [Internet]. HuffPost. HuffPost; 2020 [cited 2020Apr20]. Available from: https://www.huffpost.com/entry/how-long-coronavirus-live-clothing-washing_l_5e724927c5b6eab779409e74}