General, Research, Technology

Can coronavirus survive exposure to high temperatures?

While many countries are trying to cope with the influxFor patients infected with CoVID-19, scientists around the world continue to study the new coronavirus. The reason for such close attention to SARS-CoV-2 is that we still know very little about it, but new data is gradually appearing. So, recently, scientists from the department of new viral diseases at Aix-Marseille University in France found that strains of the SARS-CoV-2 virus that causes CoVID-19 can withstand temperatures of 60 ° C for an hour. Let me remind you that according to previous studies, the coronavirus died at a temperature of 60 ° C after a few minutes. However, in order to kill the virus in the laboratory, scientists had to heat it to 92 ° C for 15 minutes. It should be noted that the study published on the bioRxiv preprint server has not yet been published in a scientific journal and has not passed an expert assessment. This means that the results obtained should be treated with caution. However, in early April, a team of researchers from Hong Kong University received similar results. Their work has not yet been published. So is it possible to kill coronavirus with high temperatures?

Coronavirus SARS-CoV-2 is rapidly changing our lives. But how to kill him?

How to kill a coronavirus?

New coronavirus pandemic is a majora threat to the life and health of the inhabitants of our planet. Having spread early this year, CoVID-19 has already infected more than two million people and claimed the lives of more than 130 thousand in different countries. In Russia, as well as in most other countries, isolation was introduced, and in the capital the introduction of access control gradually began. These measures are necessary to slow the spread of new coronavirus and reduce the burden on health systems. The virus itself first appeared in the Chinese city of Wuhan, where it was allegedly transmitted from animal to human.

Let me remind you that despite periodically pop-upIn the media, rumors about the artificial origin of SARS-CoV-2, this version was refuted as a result of scientific research. I wrote more about this in a previous article. It is believed that the new coronavirus could be transmitted to humans from bats or snakes, but recently discovered viruses similar to SARS-CoV-2 in pangolins do not exclude another zoonotic hypothesis. Studies on the origin of CoVID-19 and the search for a null patient are ongoing.

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Meanwhile, French scientists decidedtry to destroy the SARS-CoV-2 strains in the laboratory. The preliminary results can be found here. They wanted to find out under what chemical and thermal effects the virus dies. Let me remind you that according to the World Health Organization (WHO) - which is the most reliable source of information to date - coronavirus is able to survive up to three hours in the air and from several hours to several days on different surfaces. It is possible to destroy the virus by splitting its lipid (fat) membrane with the help of thorough washing of hands with soap and also treatment with alcohol antiseptics.

Do not underestimate the danger laboratory workers are exposed to when working with CoVID-19

One of the paramount tasks thatFrench researchers have posed this risk that the virus poses to laboratory staff who regularly come in contact with SARS-CoV-2 samples. During the study, the team took the kidney cells of an African green monkey and infected them with a coronavirus. Then the researchers created different conditions: “clean”, which are laboratory conditions, and “dirty”, which are more like conditions outside the laboratory walls. Then, experts conducted 10 different experiments, using different methods to destroy the virus, which included heating to high temperatures and exposure to chemicals.

The results of thermal tests showed that the virus died only after it was exposed to a temperature of 92 ° C for 15 minutes. Two other thermal conditions - 60 ° C for 60 minutes and 56 ° C for 30 minutes led to a “clear drop in infectious ability" of coronavirus, but at the same time, some samples with a higher viral load remained active.

Jeremy Rossman, Senior LecturerVirology at the University of Kent, UK, which was not involved in the study, told Newsweek that the results are important for laboratory staff. If the results pass an expert evaluation, then all the recommendations specified in the work on handling SARS-CoV-2 samples in the laboratory will be useful to scientists around the world.

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But what are the results obtained by researchers fromHong Kong In the course of the work, specialists placed virus samples with a known concentration under certain conditions, timed and measured whether the concentration of the virus in the samples changed. The results showed that at a temperature of + 4 ° C, the concentration of the virus decreased by only 7.2%, and at 22 ° C it fell twice in a week. In this case, heating to 37 ° C reduced this time to one day. With a further increase in temperature, the concentration of the virus dropped sharply, so that after heating to 56 ° C, the half-life of the virus particles was 10 minutes, and at 70 ° C the entire virus population died in five minutes.

See also: Coronavirus: everything that we know at the moment

In another experiment, scientists applied dropsfluids with SARS-CoV-2 on different surfaces and detected the time during which the viral particles survive at room temperature and humidity of 65%. It turned out that on ordinary and sanitary-hygienic paper, the concentration of the virus fell twice in 30 minutes, and three hours later there was nothing left of the virus. But on the tree, the virus clearly felt better — the half-life of the coronavirus was 24 hours. The same results were obtained on the fabric, however, which one is not clear. As for glass, the pathogen concentration decreased by half only two days later, exactly the same situation was observed on the surfaces of banknotes. When applied to plastic, steel and the inner layer of a medical mask virus concentration decreased by 50% in four days.

On the outer layer of the surgical mask, the concentration of coronavirus decreased by half only after a week.

The results obtained by Chinese scientists showed that 65% humidity and moderate temperature reduce the infectivity of the virus

However, the most important data were obtained by scientists duringanalysis of the level of infection in 100 Chinese cities. It turned out that higher temperatures and humidity levels apparently significantly reduce the transmission of CoVID-19. According to researchers, this corresponds to acute respiratory viral infections and influenza, which under similar conditions also significantly reduce the transmission of viral particles. But what does all this data mean to you and me? Unfortunately, so far the results of studies of the new coronavirus suggest that it is a fairly stable strain, both in terms of temperature and in its ability to survive on various surfaces for a long time. However, exposure to high temperatures (above 60 ° C) from 5 to 15 minutes can actually kill the virus. The results can be found on the preprint server

Nevertheless, to the preliminaryThe results so far need to be treated with caution and wait for an expert assessment. One way or another, CoVID-19 is not the only pathogen that humanity has encountered, so victory in any case will be ours. Unless, of course, we follow the recommendations of the WHO and follow the regime of self-isolation. Be healthy.