Coronavirus lifespan: surface, air, skin, fabric?
"Coronavirus lifespan: surface, air, skin, tissue?"
The Covid-19 could be transmitted by air at more than 2 meters estimate the American health authorities. Plastic, copper, glass, fabric, smartphone screen... Do we know how long the coronavirus survives outside the body, on an object, on a surface or on the skin? Studies and answers of scientists.
Discovered in Wuhan, China in December 2019, the coronavirus responsible for Covid-19 is a particularly contagious virus. Permanently under the radar of infectiologists, virologists and other scientists, this virus has a level of contagion, a mode of transmission, an incubation period and a fatality rate that we know better and better. But what do we know about its lifespan? How long does it remain infectious? What is its resistance on different materials? On the plastic? On the skin ? And under the soles of shoes? Update on the various studies.
Lifespan of the coronavirus on a smartphone?
In a study by the Australian National Science Agency (CSIRO), researchers estimated that Sars-CoV-2, the virus responsible for Covid-19, would be able to survive up to 28 days on smooth surfaces, such as smartphone screens, glass, stainless steel or banknotes, at a temperature of 20°C, i.e. approximately at room temperature. At 30°C, this survival rate would drop to 7 days and at 40°C, the virus would only survive for 24 hours. On the other hand, on porous surfaces like cotton, the virus survived for a shorter time, up to 14 days at the lowest temperature and less than 16 hours at the highest. "Our results show that SARS-CoV-2 can remain infectious on surfaces for long periods of time, reinforcing the need for good practices such as regular hand washing and surface cleaning," said Dr. Debbie Eagles of the Center. Australian Disease Preparedness.
Lifespan of the coronavirus on the skin?
A study by Japanese researchers at Kyoto Medical University, the results of which were published October 3 in the journal Clinical Infectious Diseases, found that Sars-CoV-2, the virus responsible for the Covid epidemic -19, could survive up to 9 hours on human skin. While the seasonal flu virus had a lifespan of less than two hours on the skin. To achieve these results, the scientists conducted their experiment in the laboratory on forensic autopsy skin samples, normally intended for transplants. In contrast, both viruses were completely eliminated within 15 seconds when the skin samples were disinfected with an 80% alcohol-based hydroalcoholic solution.
Lifespan of coronavirus on a mask?
In a study published in the medical journal The Lancet, researchers analyzed the lifespan of the coronavirus under conditions close to normal life (a temperature of 22°C with a humidity level around 65%) on different surfaces. Main finding: traces of coronavirus - at a detectable level - can be detected for up to 7 days on the outer face of a surgical mask after contamination and up to 4 days on the inner face of a mask after contamination.
Lifespan of the coronavirus in the air?
According to the US Centers for Disease Control, the coronavirus could indeed be spread and transmitted through the air. In an update to their website from October 5, 2020, the scientists indicate that the small droplets and viral particles would be able to remain suspended in the air for several hours and infect people who are more than 2 meters away. the infected person. However, the main route of contamination remains the inhalation of respiratory droplets when the infected person sputters, coughs or sneezes. Previously, a study* conducted by American researchers and published on March 17, 2020 in The New England Journal Of Medicine revealed how long the coronavirus can survive in the air and on different surfaces. Results. To determine the lifespan of the coronavirus in the open air, the researchers used a nebulizer, a device that transforms liquid (here droplets containing Covid-19 viral particles) into very fine particles. These particles were then sprayed using an aerosol in the ambient air and on different supports, with the aim of imitating the projections of saliva from a contaminated person who coughs or sneezes. At the end of their experiment: the researchers found fine viable particles of coronavirus suspended in the air 3 hours after having sprayed them in the air. The viral load had however dropped slightly (it went from 103.5 to 102.7 TCID50 per liter of air at the end of the experiment). In other words, the coronavirus could remain viable and infectious in the open air for up to 3 hours. These figures should be taken with caution because they depend on the quantity of viral loads emitted into the air. In this experiment, the aerosols were extremely concentrated in virus particles, which is not necessarily the case when a person coughs or sneezes. "At the moment, we do not know how many viral particles are emitted when an infected person coughs or sneezes", indicate the authors of the study. It is therefore difficult to determine the risk of environmental contamination and how long the virus will precisely persist in the air. In a letter made public on Monday July 6, nearly 240 scientists alerted the World Health Organization to the risk of "airborne transmission of Covid-19". According to these researchers, the viral particles of the virus would be able to remain suspended in the air, well beyond two meters, and therefore there would be a risk of transmission through the air. “There is significant potential for risk of inhalation of viruses contained in microscopic respiratory droplets (microdroplets) at short and medium distances (up to several meters, on the order of room scale), and we advocate the use of preventive measures to prevent this route of airborne transmission,” they say. In the absence of proof, they advise to better "ventilate workplaces, schools, hospitals, EHPAD and retirement homes" by installing air filters or special ultraviolet rays capable of killing microbes in the ducts. 'aeration.
• Remember: depending on the viral load concentration of the droplets emitted, the ambient temperature or humidity, the duration of the virus in the air can vary from 0 to 3 hours, as was the case for the coronavirus at the origin of the Sras epidemic (in 2002) or the Mers (in 2012).
Lifespan of coronavirus in water?
Can you catch Covid-19 in water? Asked about this, the High Council for Public Health considers that "no data on the survival and maintenance of the infectious nature of the SARS-CoV-2 virus in the waters of the natural environment currently exist". In other words, the Covid-19 could not be transmitted via water. Indeed, according to a study carried out by the Spanish Superior Council for Scientific Research (CSIC), the salt present in seawater would reduce the viral load of Covid-19. In swimming pools and hot tubs, the use of chlorine as a disinfectant could have the same power. On the other hand, in fresh water such as in a lake or in a river, the survival of the virus could be longer, indicate the authors of the study. In addition, according to the French Research Institute for the Exploitation of the Sea (Ifremer), no trace of the coronavirus has yet been detected in seawater samples or shellfish collected from different places on the coast. French.
Lifespan of the coronavirus on different materials?
The results of the American study also showed that the Covid-19 virus could remain viable and infectious for several hours to several days on different surfaces:
It is not known for sure how long this novel coronavirus survives on surfaces but it appears to behave like other coronaviruses. Studies (and preliminary information on COVID-19) tend to show that coronaviruses can persist on surfaces for hours to days. "This may also depend on other parameters such as temperature or ambient humidity" confirms the World Health Organization on its website. However, these results make it possible to have an order of magnitude on the lifespan of the coronavirus and to compare them on different surfaces.
• If in doubt, regularly clean potentially infected surfaces (particularly telephone screens, door handles, light switches, stair railings, etc.) with a disinfectant to kill the virus. “There are chemical disinfectants that can kill Covid-19 on surfaces. These include bleach or chlorine based disinfectants, solvents, 75% ethanol, peracetic acid and of chloroform", specifies the WHO. In case of contact with this surface, wash your hands with soap and water or with a hydro-alcoholic solution, and avoid touching your eyes, mouth or nose.
Can the coronavirus survive on an object or a package?
Given that a virus can remain viable and infectious for several hours on a surface, contamination is theoretically always "possible" on contact with a contaminated object or an infected surface. However, the contamination by the materials would represent “potentially a very small part of the transmissions” specify the authors of the study. In this context, the risk of contracting the coronavirus through contact with a package that has been moved, that has traveled and that has been exposed to different conditions and temperatures, is very low, if not non-existent.
"It is possible to catch Covid-19 by touching a surface or an object where the virus is located and then by bringing your hand to your mouth, to your nose, to your eyes, but this is not the main mode of transmission,” confirms the Centers For Disease Control and Prevention, the United States Public Health Agency. In France, Public Health France has also agreed that the coronavirus is mainly transmitted by direct and close contact, namely between two people located less than one meter apart, through respiratory droplets expelled through the nose. or by mouth when a person coughs or sneezes.
Can the coronavirus survive on shoes?
A recent study conducted by the Wuhan Academy of Military Medical Sciences in China, relayed by the Japan Times, revealed that the virus could survive on the soles of shoes, in particular those of medical personnel in Covid-19 services. The results were published on Friday April 10 in the journal of the United States Center for Disease Control and Prevention. To reach this conclusion, the scientists analyzed surface and air samples from an intensive care unit and a Covid-19 ward at Huoshenshan Hospital in Wuhan (China) receiving 24 patients between February 19 and March 2. At the end of their study, the researchers determined that the soils analyzed had high levels of virus particles "perhaps due to gravity and airflow which cause most virus droplets to float towards the soil". In addition, half of the samples from the soles of medical staff's shoes tested positive for Covid. The soles of shoes could therefore "function as carriers" and therefore vectors of transmission of the coronavirus. In this context, the researchers invite healthcare personnel to regularly wash and disinfect their shoes, especially when they leave rooms that house contaminated people.
Is there a risk of food contamination?
For the moment, “the transmission of the coronavirus by the direct digestive route has been ruled out” reassures the National Food Safety Agency (Anses) in a press release dated March 11. Furthermore, since the contamination of an animal is unlikely, the possibility of direct transmission of the virus by food from a contaminated animal has been ruled out by the experts. In other words, the coronavirus cannot be transmitted by meat or fish, as long as they are cooked. However, to minimize the risks:
Transmission: what precautions to limit the risks?
To limit the contagion of the coronavirus, it is essential to respect barrier gestures and social distancing instructions:
* Study "Aerosol and Surface Stability of SARS-CoV-2 as Compared with SARS-CoV-1", New England Journal of Medicine, Universities of California, LA, Princetown, March 17, 2020.
Coronavirus lifespan: surface, air, skin, fabric?Lifetime on a phoneLifetime on skinLifetime on a maskLifetime in airLifetime in waterLifetime on different surfaces• Lifetime on plastic• Lifetime...
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