Covid-19: Still worried about deep cleaning? You may take it easy now

Research published in March 2020 brought intense focus on fomites and thus on deep cleaning, requiring the use of disinfectants.

Alook at the Covid-19 situation in India at this time last year appears to be a tale from an ancient era. Exactly a year ago, on April 12, India had a Covid-19 caseload of 9,211, with a daily contribution of 758. The country was under complete lockdown and coronavirus created a fear.

Situation elsewhere in the world was bad. Cases were popping up from all parts of the developed world with reports focusing on the healthcare infrastructure crumbling under the load of Covid-19 cases.

There was still confusion whether common people should wear masks and gloves or these ‘medical’ items should be left for the use of healthcare workers. The World Health Organisation had not yet recommended wearing face mask as a way to prevent Covid-19 spread. It had been recommended in India though.


Research published in March 2020 brought intense focus on fomites and thus on deep cleaning, requiring the use of disinfectants. The laboratory study showed that SARS-CoV-2, the coronavirus that causes Covid-19, could stay alive for up to three days on plastic and steel surfaces.

Touching a doorknob, a metro rail pole or an escalator handlebar became a risky affair. Covid-19 was still mostly an unknown disease. The WHO guideline issued in February too highlighted the risk of Covid-19 spread through contaminated surfaces, called fomites.

By May 2020, the disinfectant producing factories were working overnight worldwide to meet the demand. Houses, offices, shared vehicles, religious places, shops and other community places were recommended to go for deep cleaning to mitigate the spread of Covid-19.


A change in understanding the coronavirus infection began in July 2020, when microbiologist Emanuel Goldman wrote a commentary in The Lancet Infectious Diseases. Goldman called the deep cleaning guideline to prevent spread of Covid-19 an “exaggerated risk” assessment.

The principal argument against deep cleaning was that the contaminated surfaces or fomites presented very low risk of transmission of coronavirus. Other studies also came later on.

This led the US Centers for Disease Control and Prevention (CDC) modify its earlier Covid-19 safety guideline — from surfaces not “the main way” to surfaces not “a common way” for Covid-19 spread.


Last week, the CDC updated its Covid-19 guidelines which came as an about-turn saying that the chance of catching coronavirus infection from a contaminated surface is less than one in 10,000 instances. The CDC practically said the deep cleaning move was overkill.

Recently, the New York Times quoted a health expert as saying, “There’s really no evidence that anyone has ever gotten Covid-19 by touching a contaminated surface.”

This means the obsessive scrubbing of surfaces in homes, in offices or religious places, of quarantine packages is no longer essentially required. Also, production, sale and purchase of disinfectant liquids and wipes could now return to pre-Covid-19 normal.


India’s case was no different from rest of the world’s. At some places, fleeing migrant workers were ‘cleaned’ by disinfectants as the authorities did not have a clue how to sanitise such a volume of moving population carrying the risk of Covid-19 spread.

When airlines resumed their operations last year after lockdown, a three-hour deep cleaning procedure was strictly followed. This led many a time delay in departure of flights despite an overall reduction in the number of operating flights.

Wrapped in PPEs (personal protective equipment), personnel entered an aircraft and deep cleaned everything, from the lavatories, seats, foldable tables, windows, baggage cabins to the cockpit. This was when only those passengers were allowed to travel who met certain screening criteria.


The CDC has said in its updated guideline that we don’t need chemical disinfectants to keep surface transmission low. Washing hands, wearing a face mask, and cleaning surfaces with regular soap and water are enough to keep us protected from catching Covid-19.

Same protocol was recommended for the trains and public transport buses. Government offices were deep cleaned regularly and every private firm that could afford followed suit.

The principal mode of Covid-19 spread is through droplets coming out of the mouth and nose of a coronavirus infected person. If all persons wear face masks whenever they interact with others, spread of Covid-19 can be drastically reduced.

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