Tables, doorknobs, switches put you at risk of Covid-19

The chances of you picking up the virus that causes coronavirus disease 2019 (Covid-19) from your office desk or the banisters on the staircases are exponentially high, as the virus (scientifically known as SARS-CoV-2) has been found to survive for up to three days on some surfaces.

From the findings, the coronavirus can live for up to four hours on copper, 24 hours on cardboard and up to two to three days on some surfaces like plastic and steel. In the latest scientific paper, the virus has been found to be stable for several hours to days in the air and on surfaces.

Tracking coronavirus

Like other coronaviruses, it is known that Covid-19 can spread from close person-to-person contact through respiratory droplets, according to the Centers for Disease Control and Prevention (CDC).

Further, the CDC's website says surfaces can be contaminated with Covid-19, adding that though there are no known cases that started in that manner.

In latest published findings, scientists from the National Institutes of Health (NIH), CDC, UCLA, and Princeton University found the virus can remain infectious in droplets in the air for hours and surfaces for days. The study also suggests that people may get the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) "after touching contaminated objects."

When it becomes suspended in droplets smaller than five micrometres — known as aerosols — it can stay suspended for about a half-hour, researchers said, before drifting down and settling on surfaces where it can linger for hours.

This part of the finding conflicts with the World Health Organisation’s (WHO) position that the virus is not transported by air.

“Our results indicate that aerosol and fomite transmission of SARS-CoV-2 is plausible since the virus can remain viable and infectious in aerosols for hours and on surfaces up to days,” the researchers noted in the paper on Tuesday.

Fomites are objects or materials which are likely to carry infection, such as clothes, utensils, and furniture.

This then could inform how the general public and health care workers try to avoid transmission of the virus. Health experts and scientists have repeatedly advised that proper hand washing with soap and water, use of a 60 per cent alcohol-based hand sanitizer, and disinfecting surfaces. To limit the spread of the virus the CDC and the WHO have suggested daily cleaning and disinfecting frequently touched surfaces.

The agency advises people to clean and disinfect dirty surfaces in homes or community settings. Cleaning refers to the removal of germs, dirt, and impurities from surfaces while disinfecting involves using chemicals to kill germs on surfaces. Both methods can lower the risk of spreading infection, the CDC said.

Recommended frequently touched surfaces include "tables, doorknobs, light switches, countertops, handles, desks, phones, keyboards, toilets, faucets, and sinks."

Published in the New England Journal of Medicine the team of researchers also suggest that the virus crumbles over the course of a day on surfaces like cardboard, reducing fears that goods made from such materials will spread the virus.

The NIH study attempted to mimic the virus being deposited from an infected person onto everyday surfaces in a household or hospital setting, such as through coughing or touching objects. The scientists then investigated how long the virus remained infectious on these surfaces.

The data consisted of 10 experimental conditions involving five environmental conditions: aerosols, plastic, stainless steel, copper, and cardboard the agency said. The scientists then investigated how long the virus remained infectious on these surfaces.

A device was also used to release the aerosol which duplicated the microscopic droplets created in a cough or a sneeze.

"The results provide key information about the stability of SARS-CoV-2, which causes COVID-19 disease, and suggests that people may acquire the virus through the air and after touching contaminated objects," the NIH said.

The findings observed how stable the virus is in aerosols and surfaces which likely means healthcare settings are vulnerable to the virus.

"Healthcare settings are also vulnerable to the introduction and spread of SARS-CoV-2, and the stability of SARS-CoV-2 in aerosols and on surfaces likely contributes to the transmission of the virus in healthcare settings," the study found.