How long does the Covid-19 survive on door handles, WCs and other everyday objects?

• To protect themselves against the coronavirus, the population is called upon to protect against the pandemic on a daily basis.
• Limitation of social interactions and diligent practice of barrier gestures are essential.
• According to a study that has just been published, the virus can survive for several days on certain surfaces.

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A threat invisible to the naked eye, but yet very real. As the Covid-19 epidemic continues to progress in France, with a significant increase in the number of new infections, the message continues to be hammered. To fight effectively, you must apply barrier gestures: conscientiously wash your hands, cough and sneeze at your elbow, use single-use tissues. And wash your hands again after all this.

Individually, everyone must comply with these health security and social distancing rules to keep the coronavirus at bay. Now that bars, restaurants, cinemas, museums and non-food shops are closed throughout France, everyone is invited to limit their trips and outings to the bare minimum, to go to work and do their shopping. But is there a risk if you touch an object or surface that has been in contact with the coronavirus? How long does the Covid-19 survive on everyday objects, whether it is the food that everyone runs to buy at the supermarket, the doorknobs or even the toilet bowl?

Up to three days of Covid-19 survival on plastic and steel

While several studies have addressed this issue, a study by American health authorities – the National Institutes of Health (NIH) – provides a little more information on the survival time of coronavirus on inert surfaces. The virologists who conducted these tests sprayed samples of Sars-CoV-2 on various types of inert surfaces and were thus able to establish that this new coronavirus could survive for up to three days on plastic and on steel, and up to 24 hours on cardboard and paper materials. What to get an idea of ​​survival of the Covid-19 if eventually it was in contact with the packages of pasta, toilet paper and other cans which the French are stockpiling in recent days. But also at home, on door handles, worktops, taps, etc. “These surfaces are the” fomites “: all objects potentially carrying germs and which can cause hygiene problems in the management of coronavirus”, explains to 20 minutes Jocelyn Raude, teacher-researcher in social psychology of health and infectious diseases at
the Graduate School of Public Health (EHESP).

The virus would survive for a shorter time on other surfaces: no more than four hours on copper, the main metal in the composition of our coins. And about three hours maximum on aerosols. Similar results to those obtained from samples of Sars-CoV-1, the coronavirus that caused the SARS epidemic, which affected Asia and the rest of the world in 2003.

Presence of virus does not mean contamination by objects

These data, which have yet to be the subject of further work, could suggest that the transmission of the virus by air and by objects is “plausible”. However, the survival of the virus on certain surfaces does not necessarily mean that the risks of being infected by touching them are proven.

Thus, the particles of the virus can be present without representing a high infectious risk, since, as Dr Angela Rasmussen, virologist at the prestigious Columbia University in New York recalls, “if the viruses can remain present on certain surfaces for several days, the number of infectious viral particles is drastically reduced, up to 1,000 times, ”she said on Twitter.

Furthermore, both viruses also showed a 3-log decrease in infectious virus on stainless steel and plastic surfaces after 48-72 hours. This suggests that, while viruses can stay on some surfaces for days, their infectious titer is greatly reduced (1000-fold).

– Dr. Angela Rasmussen (@angie_rasmussen) March 11, 2020

Disinfect, disinfect and disinfect

The American virologist, however, recalls the importance of barrier gestures and recommends “regularly disinfecting door handles, counters, washing your hands frequently, not touching your face and practicing social distancing”.

This information is useful to the public, in that it can help us take precautions to avoid exposure / transmission. Wipe down / disinfect shared surfaces (doorknobs, counters, etc). Wash your hands frequently and don’t touch your face. Social distancing practice.

– Dr. Angela Rasmussen (@angie_rasmussen) March 11, 2020

Dr. Rasmussen reassures those who are worried about receiving contaminated boxes since the coronavirus does not survive there for more than 24 hours, but calls on the deliverers to take extra hygiene precautions. Because respect for
barrier actions remains the key against the spread of coronavirus.

Thus, a previous study, published March 5 in the American scientific journal JAMA, showed that patients with Covid-19 contaminated their bedroom and bathroom extensively, highlighting the need to regularly clean surfaces like sinks and basins. For their work, the researchers examined the rooms of three patients kept in isolation. One of the rooms was tested before its routine cleaning, while the other two were analyzed after disinfection measures. The patient whose room was tested before cleaning had a simple cough, while the other two showed more severe symptoms with cough, fever, shortness of breath for one and sputum of pulmonary mucus for other.

Despite his mild symptoms, the first patient contaminated thirteen of the fifteen surfaces analyzed by the researchers, including his chair, bed, window and floor. In his toilets, three of the five surfaces tested, including his sink and bowl, showed traces of the virus, suggesting that stool could be a route of transmission. The study, conducted by researchers at the National Center for Infectious Diseases in Singapore and the DSO National Laboratories, found that the virus does not survive cleaning contaminated surfaces with common disinfectant twice. per day.

Transmission by droplets

But keep in mind that the main mode of transmission of the virus is droplets from an infected person when they speak, cough or sneeze. Droplets that can reach anyone within a radius of one meter when not protecting themselves, hence the importance of staying confined or at least wearing a mask if you are contaminated with Covid-19.

However, many people, children and young adults in particular, can be asymptomatic carriers of the virus. And therefore not knowing that they are sick, and thus spreading the virus around them. This explains the containment measures and the closings of schools and universities announced this weekend by the head of state.

To date, France has recorded 5,423 confirmed cases of coronavirus and 127 deaths.

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