The fomite issue: how long will the novel coronavirus live outside the human body?
by Tommy Underhill
March 12, 2020
This blog is going to be technical and a bit heavy on research regarding our understanding of the viability of the novel coronavirus to survive outside the body based on our understanding of other coronavirus strains. As of March 12, 2020, there is no current non-anectdotal information regarding fomite efficacy for the 2019 novel coronavirus.
A fomite is defined as:
- An inanimate object or substance that is capable of transmitting infectious organisms from one individual to another.
- An inanimate object capable of carrying infectious agents (such as bacteria, viruses, and parasites), and thus passively enabling their transmission between hosts.
- Any inanimate object (as a towel or money or clothing or dishes or books or toys etc.) that can transmit infectious agents from one person to another
Common examples of fomites include our cell phones and tablets; car keys and house keys, keyboards and mice; pens and staplers; doorknobs; desks and counter tops; soda cans, water bottles, and drinking glasses; and light switches... pretty much everything you can think of, including the kitchen sink.
The problem with novel coronavirus fomites is two-fold: (1) finding all of them and disinfecting all of them, and (2) knowing how long the coronavirus will remain viable on a fomite surface.
I have seen no published data concerning the 2019 novel coronavirus. Instead, I’ll refer to other coronavirus strains associated with outbreaks in this century: SARS-CoV coronavirus from 2003 and MERS-CoV in 2012.
SARS: (Severe acute respiratory syndrome)
For nine months spanning November 2002 until July 2003, the SARS outbreak in southern China produced a total of 8,098 cases, with 774 deaths reported in 17 countries resulting in a 9.6% case fatality rate. The primary route of transmission for SARS is contact of the mucous membranes with respiratory droplets or fomites. Generally speaking, everyone understands direct droplet transmission, so we will examine the situations regarding fomites.
In reference to the stability of the virus outside the body for SARS-CoV, the WHO consensus document reported:
Data from the Chinese University in Hong Kong indicated that SARS-CoV has been isolated from stool on paper, a Formica surface and a plastered wall after 36 hours, on a plastic surface and stainless steel after 72 hours, and after 96 hours on a glass slide. Hospital environmental samples from a number of sites, including walls and the ventilation system, tested PCR positive in Canada.
World Health Organization
Consensus document on the epidemiology of severe acute respiratory syndrome (SARS), p. 29
Under favorable conditions, a subsequent study confirmed that SARS-CoV viably persists for days.
In the present study, we have demonstrated that SARS CoV can survive at least two weeks after drying at temperature and humidity conditions found in an air-conditioned environment. The virus is stable for 3 weeks at room temperature in a liquid environment.
Chan, K. H., et.al.
The effects of temperature and relative humidity on the viability of the SARS coronavirus. Advances in virology, 2011.
MERS: (Middle East respiratory syndrome)
MERS was first reported in 2012 and as of July 2015, MERS-CoV cases have been reported in over 21 countries. Over 2,000 cases of MERS have been reported by 2017 with approximately 600 deaths, and the case fatality rate is greater than 30%. Dr. Anthony S. Fauci, head of the National Institute of Allergy and Infectious Diseases at the National Institutes of Health, stated that as of now MERS-CoV “does not spread in a sustained person to person way at all.”
A 2013 study did determine surface viability at room temperature.
MERS-CoV virus could still be recovered after 48 hours... on plastic and steel surfaces, though not at 72 hours, at 20°C/68°F. The virus degraded more quickly at higher temperatures.
Van Doremalen, N., Bushmaker, T., & Munster, V.J.
Stability of Middle East respiratory syndrome coronavirus (MERS-CoV) under different environmental conditions. Eurosurveillance, 18(38), 20590.
Back to the novel coronavirus of 2019
Here’s where predicting the future gets rough.
If we base our understanding of the new 2019-nCoV coronavirus strain’s fomite viability as being similar to SARS and MERS, there is a real risk of potentially-sustainable, secondary environmental transmission particularly in high-exposure locations like hospitals, urgent care centers, ambulances, and nursing homes. I would think there would be far less likely to be a potential risk multiple weeks after the initial contamination, but we unfortunately just don’t know enough about this new strain— and we may not know more for a frustrating period of time.
Heat is the 100% solution now!
Heat is a proven disinfectant. Medical professionals trust autoclaves and heat to sterilize surgical instruments. When conducting a microbial treatment with GreenTech Heat equipment, heat and hold the treatment zone between 60°C/140°F and 66°C/150°F and maintain temperatures until the hardest-to-heat locations maintains that temperature for 1 hour as indicated with a temperature probe.
During a microbe-focused heat treatment, be sure to run the HVAC fan (not A/C!) during the heat treatment process to get lethal levels of heat inside this system should it house any viral contamination. Do not remove the air filters during the treatment unless maintenance plans to replace them as part of the microbial heat treatment process. If this is the case, remove the old filters prior to the heat treatment and then install the new filters after the viral heat treatment.
GreenTech Heat has been used to disinfect schools, churches, offices, and public buildings of the bird flu virus, H5N1, and the swine flu virus, H1N1.
Tom Costello, Technical Director at GreenTech Heat, said, “Treating structures with the heat process will slow this contagion without the need to wipe down contents with chemical disinfectants to eliminate fomites on surfaces.” Previous coronaviruses including SARS and MERS could last as long as two weeks in an air-conditioned environment. The GreenTech Heat process will also provide legitimate peace of mind that the structure is free of viral contamination.
A single treatment with temperatures only slightly higher and durations slightly longer than an aggressive bed bug treatment will eliminate organisms throughout the treatment area. A complete listing can be found in Bed Bug Heat Treatment Field Guide.
Who can benefit from an antimicrobial heat treatment?
- Government facilities
- Hospitals and emergency rooms
- Urgent care facilities
- Medical offices
- Rental car fleets
- Retail establishments
GreenTech Heat technology allows you to self-treat with heat for the coronavirus on your schedule and as your needs demand. Our certified training lets you do it right and do it safely the first time. Regardless of whether you self-treat with heat, or contract a heat professional, heat safely kills the coronavirus everywhere it may be found in a single one-day treatment. Call us at 888-699-3944 to get started with heat today.