Coronavirus capable of surviving on surfaces up to three days, new study shows

Research shows virus can also remain airborne for 30 minutes

Coronavirus can survive on certain surfaces, such as plastic and steel, for up to three days, according to new research that sheds light on the stability and viability of the pathogen.

In a study published in The New England Journal of Medicine, scientists found SARS-CoV-2, which causes the Covid-19 disease, was detectable in aerosols for up to three hours, up to four hours on copper, no longer than 24 hours on cardboard and up to three days on plastic and stainless steel.

The research, led by the National Institute of Allergy and Infectious Diseases (NIAID), sought to mimic the virus being deposited from an infected person onto everyday surfaces in a household or hospital setting, such as through coughing or handling objects.

The findings highlight the main risk of contracting the virus after touching contaminated objects, but also the small danger of airborne transmission.

In line with the World Health Organisation, experts have maintained for weeks that the pathogen cannot be spread through the air – but the new research suggests it can be transmitted via droplets released when an infected individual coughs or sneezes.

However, the virus does not linger in the air at high enough levels to be a risk to most people who are not physically near an infected person. Instead, it will travel through the air and stay suspended for about 30 minutes before settling on surfaces, the study said.

In a controlled set-up where scientists used a rotating drum to suspend contaminated aerosols, and provided temperature and humidity levels similar to hospital conditions, the virus survived for up to three hours – though its ability to infect drops sharply over this time.

That the virus can survive and stay infectious in aerosols will be of most concern for health care workers treating patients on a daily basis, though great protective lengths are already being taken by those on the frontline fight against Covid-19.

In a separate study published earlier this month in JAMA, the virus was located on a ventilator in the hospital room of an infected Singaporean patient, where it could have only been transmitted via the air.

NIAID showed that the virus lives longest on plastic and steel surfaces, surviving for up to 72 hours. But the amount of viable virus decreases sharply over this time. On copper, in contrast, it takes just four hours for the pathogen to become inactivated.

The scientists were also able to compare the viability – or how long it stays infectious for – of SARS-CoV-2 with SARS-CoV-1, which caused the SARS outbreak between 2002 and 2003.

Although both viruses behaved similarly under the study, most secondary cases of virus transmission of SARS-CoV-2 appear to be occurring in community settings rather than healthcare settings, the study suggested.