After the recent news of the increase in the incidence of cases with COVID19 worldwide, the omicron variant is added.
This new variant spreads faster than the other strains recorded so far.
We are back with restrictions and with the recommendation of the 3rd vaccine.
We encourage you to learn more about this new variant through this link.

Many of you have wondered, after having been infected or after contact with a positive person, how long will the COVID-19 virus live on surfaces or in indoor air?
When will things be safe again, including my clothes and my home or workplace?
An article published in the newspaper El País talks about how the virus spreads indoors: https://elpais.com/ciencia/2020-10-24/un-salon-un-bar-y-una-clase-asi-contagia-el-coronavirus-en-el-aire.html

COVID on surfaces

Many of us have wondered if a contaminated fomite can infect a person.
But what is a fomite? It is any object that, if contaminated with any viable pathogen, such as bacteria, viruses, fungi or parasites, is capable of transferring said pathogen from one individual to another.

The studies carried out on surfaces have a drawback, they have been carried out in laboratories where the viral load is very different from that of real life.
Outdoors, not only does the amount of virus present in the environment influence, but also environmental conditions such as temperature, darkness, ventilation,_CO2 levels…

Unfortunately, the presence of the virus is not seen, so we cannot know if someone is infected and is infecting the environment.

We all want to know when something becomes safe

In September 2020, a study was published in the Clinical Microbiology and Infection in which researchers from Israel tried to reconstruct everything.
Studies were carried out in the laboratory where samples were left for days on various surfaces.
They found that the longest period where they found the presence of virus in fomites was 6 days.
Despite that, none of these studies present scenarios similar to real-life situations.

The next part of this study was to collect samples from highly contaminated environments, such as the isolation ward in a hospital, the ICU, etc.
In these environments, the presence of the virus abounded.
It is noteworthy that environmental surface contamination decreased after week 1 of illness.
The results, despite the contamination of the fomites, reveal that the samples were not infectious, that is, that the virus is not viable if it is in the presence of an object or a surface. The conclusion they reached is that it seems unlikely that environmental contamination will lead to the transmission of SARS-CoV-2 as long as standard cleaning and precautions are sought.

https://www.thelancet.com/journals/laninf/article/PIIS1473-3099(20)30678-2/fulltext

Not all studies have the same conclusion as the one mentioned above.

A study conducted in a laboratory verified the stability and level of infectiousness of the SARS-CoV-2 virus on non-porous surfaces.
Viral RNA was detected by RT-PCR in COVID-19 isolation units and in a hotel where quarantine was sought.
Under laboratory-controlled conditions, SARS-CoV-2 gradually lost its infectivity on the 4th day at room temperature. The rate of decomposition of viral viability is directly proportional to the increase in temperature.

https://www.sciencedirect.com/science/article/pii/S1198743X20305322

The conclusions in another study were completely different.
At room temperature, the virus remained longer.
At 20ºC they were able to detect the presence of the SARS-CoV-2 virus after 28 days on non-porous surfaces such as glass, stainless steel, vinyl, etc.
On porous surfaces such as cotton fabrics, their presence decreased earlier compared to non-porous ones.
After 14 days, the porous surfaces no longer had traces of virus.
Notably, most of the reduction of the virus in cotton occurred shortly after infection.

https://virologyj.biomedcentral.com/articles/10.1186/s12985-020-01418-7

How do we spread surfaces?
Saliva present on surfaces

One of the leading theories is how saliva droplets can contaminate a surface.
One study determined how long certain viral proteins in saliva belonged intact.
This is also very useful in determining the reliability of saliva tests for COVID-19.

The study considered the chain of events that can happen to spread the virus on surfaces.
In this theory, an infected person could spray a large amount of virus onto the surface.
This surface should be made of a certain material, exposed to an appropriate level of light, temperature and humidity so that the virus does not degrade quickly.
Later we should have contact with that contaminated surface.
Finally, the virus present on the surface has to find its way inside our body.
So a concentration large enough to overcome our natural mucosal defenses and settle in our cells should enter through the nose or through the eye.
The conclusion of this study is that SARS-CoV-2 infection through saliva and surfaces is of low risk.

Low risk does not imply no risk

There is always a minimum risk.
There are high-contact objects that need to be disinfected regularly, such as hospitals.
People at high risk for a complicated illness should take extra precautions.

However, the best advice is to break the chain that the studio had been treating and avoid contact with the nose and eyes.
That is why the health recommendations insist: WE MUST ALWAYS WASH OUR HANDS WELL.

Person-to-person transmission

Since the results were published showing that the transmission of COVID-19 through fomites was low, the next question to ask is how it is transmitted.
The next theory is person-to-person transmission through breathing.

Experts are aware that droplets passed through sneezing, coughing, or talking are probably the most important mode of transmission.
This has been demonstrated through studies with aerosols, which remain suspended in the air.
This better explains why so many infections are passed from person to person without the need for direct interaction.

Conclusion

The findings demonstrate that even though SARS-CoV-2 may still be temporarily present on objects or surfaces.
This does not mean that the risk of contamination is high.
On the contrary, it is low.

The good news is that these results can let us breathe a little longer.
In the same way that has happened to us in quarantine, having to put our personal belongings aside for a while also wears us out psychologically.
“There’s such a high level of tension in our lives and in decision-making right now. We all need to feel calm.”

Despite the low risk of contamination through fomites, we continue to advise, disinfect with alcohol spray, clean clothes well and clean hands thoroughly after touching any object as maximum prevention.

Dr.
Gloria Sabater