QCOSTARICA – Cleaning and disinfecting with alcohol, several times a day, tables, doorknobs, desks, and any other surface in the home; sanitizing grocery bags and groceries, or bathe and change clothes as soon as you get home, are all practices common during the first months of the pandemic and people still do today, however, did not turn out to be as useful in preventing covid-19 as was believed.
In the beginning, it was normal to see laboratory studies of how much the SARS-CoV-2 virus, which causes covid-19, could survive on wood, plastic, cardboard, or other materials.
None of these studies present scenarios akin to real-life situations.
“There were experiments that showed very high levels of virus, something that you would not find in the real world. Others used saliva substitutes and tried to control humidity and temperature, but they weren’t real conditions either,” explains Emanuel Goldman, a microbiologist at the Rutgers New Jersey Medical School, in the U.S., who studies the transmission of this virus through contact with objects.
“In my opinion, the chance of transmission through inanimate surfaces is very small, and only in instances where an infected person coughs or sneezes on the surface, and someone else touches that surface soon after the cough or sneeze (within 1–2 h). I do not disagree with erring on the side of caution, but this can go to extremes not justified by the data,” Goldman published The Lancet, a weekly peer-reviewed general medical journal.
Today it is known that transmission by fomites, that is, through surfaces or objects, occurs very marginally and it is not necessary to carry cleaning practices to such an extreme.
Why was contagion through surfaces talked about?
At first, there was talk of contagion through surfaces due to ignorance of the virus, but now much more is known about it.
“Given the initial fear that it could be transmitted by direct or indirect contact with surfaces, we began to try to clean everything at all times, today we know that this has no impact,” said Juan Luis Mosqueda, a Spanish physician specializing in Infectology.
For the dialectologist, we can eliminate this small possibility of contagion with a normal cleaning of surfaces (such as those prior to the pandemic) and with rigorous hand washing.
How could a transmission by fomites be given? Goldman summed it up in an article in The Lancet.
“If an infected person sneezes or coughs and the droplets of it fall on a table and, moments later, another person touches the droplets on that surface and immediately touches their nose, eyes or mouth there, we could become infected.
Hence the importance of washing our hands.
“I do not intend to fight with your ‘care’, if you want to continue ‘sanitizing’ everything, that’s fine, what I want is that we don’t get distracted by doing useless things and stopping doing those that really impact,” Mosqueda stressed to the Spanish press.
Added to this is an experiment conducted by Tufts University in Medford, Massachusetts, Environmental engineer Amy Pickering and her team looked at contamination levels and examined how much people touched surfaces such as doorknobs or doorknobs. a pedestrian traffic light.
They estimated that the risk of infection from touching a contaminated surface is less than 5 in 100,000.
“Many things must happen and coincide for this virus to be transmitted like this,” Pickering said in a statement.
Most important: prevent airborne transmission
How should we take care of ourselves? The specialists sum it up like this: our main concern should be people, not objects.
Transmission through the air is more likely, experts agree.
And that is where masks do their job, physical distancing, and avoiding crowds, as well as closed spaces with little ventilation.
“If you go to the supermarket, the danger is not in the bags you bring home, the danger is in the air you breathe there. And what one needs is to be in a spacious and well-ventilated supermarket, and with a very well-placed mask,” said Jose Luis Jiménez, professor of Chemistry and Environmental Sciences at the University of Colorado, who is aerosol specialist.
Transmission through the air occurs in two main ways.
One is through droplets of saliva: when a person with the virus speaks, sneezes, coughs, or breathes, droplets come out in which the virus travels and can enter the other person through their mouth, nose, or eyes.
The other way is through aerosol transmission. They are even smaller particles that are suspended for a time in the air and that if a person arrives and breathes these particles through their mouth or nose (or they reach their eyes) they could be infected.
This contagion is more frequent in closed places and with little ventilation. If the space is open or with good air circulation, this will help to dissipate the particles with the virus.
How to combat this type of contagion?
The forms of prevention are not far from recommendations that have already been given to us.
- – Maintain a distance of at least 1.8 meters from those who do not live with us.
- Use masks in closed places and in open places where there is no possibility of keeping a distance from other people.
- Avoid small, closed places with little ventilation. If we must, open doors and windows. Do not stay there more than 15 minutes.
- Constant hand washing. Use of alcohol gel as “plan B” when soap or water is not available. This will help not only prevent covid-19, but also other diseases.
For specialists, one of the problems of believing that transmission by surfaces is important is that it gives us a false sense of security.
“If you think that the coronavirus is more common to be transmitted by surfaces than by air, you are going to be more likely to be with a group of people in a restaurant in a closed space, but that cleans their tables well. Rather, this increases the risk of airborne transmission, especially at times when people are not wearing masks because they are eating,” Goldman noted.
The downside of over cleaning
For specialists, there are also problems when cleaning and disinfecting intensively.
Very sensitive people could have reactions such as breakouts, rhinitis, cough, nausea and vomiting if it is done very constantly and with very strong products. These people include asthmatics, allergies, people with depressed immune systems, or those who suffer from migraines.
“This is particularly risky in those who do the cleaning, now they do it more frequently and with stronger products than before. We would be creating another problem for another group of people, and perhaps with this we will not control covid-19 infections, ″ said immunologist Claudia Miller in an interview with the American media Inside Journal.
According to the specialists, it is not about not cleaning at all, but about not obsessing over it.