What is COVID-19?
COVID-191,2 is the disease associated with a new strain of coronavirus that was discovered in 2019. You may also see it referred to as the Wuhan novel coronavirus, 2019-nCoV, WN-CoV, HCoV-19 (SARS-2), or SARS-CoV-2, where SARS is the acronym for Severe Acute Respiratory Syndrome, and CoV is that for Coronavirus. This blog uses the terms COVID-19 in reference to the viral infection, and SARS-CoV-2 in reference to the virus.
How is it spread?
We know that the primary transmission route for COVID-19 is via inhalation of the aerosols and droplets created when an infected individual coughs or sneezes. A single cough can produce up to 3,000 droplets, which can land on nearby people, clothing, and surfaces. Transmission of the disease can also happen through touching a contaminated surface and then touching the mucous membranes of the nose or eyes.
A recent study3 has shown that SARS-CoV-2 (specifically) can survive on cardboard for up to 24 hours, and for 2-3 days on plastic and stainless-steel surfaces. The survival time on clothing is not yet known. We do know the survival time depends on several factors, including the type of surface, temperature, relative humidity, and the specific strain of the virus.
The European Food Safety Authority (EFSA4) has stated that there is currently no evidence that food is a likely source or route of transmission of COVID-19. Experiences from previous outbreaks of related coronaviruses show that transmission through food consumption did not occur.
How can the risk of COVID-19 infection be minimized through cleaning and disinfection?
Viruses vs Bacteria
The main difference between bacteria and viruses is that bacteria are living cells that can grow and reproduce independently in most environments. Viruses are non-living particles that need a host (living cells) to reproduce. Virus particles can be up to 50 times smaller than bacterial cells. This aids their transfer to and harborage on surfaces. SARS-CoV-2 has been reported to survive on surfaces for 2-3 days. Some bacteria are known to survive for years. The presence of organic matter, e.g., food and biological fluids, is likely to offer viruses some protection from disinfectants and surface antimicrobials (as it does for bacteria), but both are effectively removed through good cleaning practices. Enveloped viruses, such as SARS-CoV-2, are among the weakest or least resistant organisms to disinfection. Many disinfectants are active against them and achieve their effective inactivation within minutes.
Consequently, routine cleaning and disinfection practices, using existing procedures, chemicals, and cleaning equipment, should continue as usual.
Additionally, given the recent scientific findings that SARS-CoV-2 can survive on surfaces for 2-3 days, more frequent cleaning and disinfection of touchpoints like door handles, handrails, door push plates, hoses, instrument panels, faucets, cleaning tools, and utensils, should be conducted. This cleaning and disinfection should also extend to surfaces in non-food handling areas such as restrooms, locker rooms, offices, break rooms, and vehicles.
Companies and individuals may like to implement a disposable gloving policy. If this is done, careful consideration must be given to when the gloves are used and removed, to ensure that the gloves themselves do not become a vector for viral transmission. The use of appropriate hand sanitizers, e.g., alcohol-based, could also be beneficial, though neither that nor gloving should replace good hand washing practices.
If a key food worker is diagnosed with COVID-19, it may be appropriate to decontaminate all surfaces that the worker could have come into contact with.
Visibly dirty surfaces should always be wet or dry cleaned prior to disinfection. This can be achieved through manual cleaning such as brushing, scrubbing, scraping, wiping, or through mechanical cleaning like the use of floor scrubbers, vacuum cleaners, etc., to remove the gross soiling. Remember that all cleaning activities can spread contamination. Use cleaning methods and materials the maximize contamination removal and minimize it spread.
Use 70% ethyl alcohol to disinfect surfaces like small reusable equipment (such as cleaning tools and utensils) and frequently touched surfaces (like door handles, handrails, etc.). This can be done by using a spray bottle or a disposable cloth. Use a fresh cloth for each piece of equipment/surface disinfected.
Sodium Hypochlorite and Peracetic acid are also effective chemicals for neutralizing viruses on surfaces. Food processors should work with chemical manufacturers to ensure proper dosage, contact times, and application. Not all chemicals are suitable for all surfaces.
As an alternative to Sodium Hypochlorite and Peracetic acid, a disinfectant that has passed EN 14476:2013 + A1 2015 can be used, at its highest recommended in-use concentration.
Heat at 133°F can also be used to kill the SARS coronavirus5. Small, washable equipment and utensils can be readily decontaminated using an industrial or domestic dishwasher, with a wash cycle that utilizes a minimum wash temperature of 133°F for a minimum of 15 minutes. Laundry (including protective clothing and cleaning cloths), and small washable cleaning tools and utensils can also be decontaminated by using a washing machine with the same minimum cycle settings.
What else can be done?
All those involved in food production, processing, distribution, sale, and delivery should be aware of how they themselves could cause the spread of COVID-19 and of the precautions, recommended by WHO, that they should take to minimize this:
- wash their hands regularly;
- cover their mouth and nose when coughing and sneezing;
- avoid close contact (<6 feet) with anyone coughing and sneezing.
They should also understand the sources of contamination, i.e., aerosols and droplets from coughing and sneezing and how the transfer can occur,
- through inhalation of virus particles in aerosols and droplets;
- through the transfer of virus particles from coughs, sneezes, and surfaces to hand;
- from hands to mucus membranes (nose, mouth, eyes); and
- from hands back to surfaces.
Cleaning equipment can itself become a vector for SARS-CoV-2 transmission. To minimize the risk of virus harborage and transfer choose equipment that is either single-use or hygienically designed (easy to clean and disinfect). Clean the equipment (by rinsing or wiping) and disinfect (using a suitable disinfectant solution, spray or wipe) between use by different workers. Further information on cleaning tool decontamination can be found here.
Specific recommendations for surface cleaning and disinfection regarding SARS-CoV-2 control are provided by the Center for Disease Control and Prevention6.