Coronavirus can survive on surfaces, air for several hours

Washington, Mar 18: The novel coronavirus can survive on surfaces or in the air for several hours, according to a US-government funded study. Scientists found that the virus that causes the COVID-19 disease had similar levels of viability outside the body to its predecessor that caused SARS.

This means that factors like greater transmission between people with no symptoms might be why the current pandemic is far greater than the SARS outbreak of 2002-2003. The new paper was published in the New England Journal of Medicine (NEJM) on Tuesday and carried out by scientists from the Centers for Disease Control and Prevention (CDC), University of California, Los Angeles and Princeton.

The new coronavirus was detectable for up to two to three days on plastic and stainless steel, and for up to 24 hours on cardboard. The team used a nebuliser to simulate a person coughing or sneezing, and found that the virus was detectable for three hours in the air.

The study was first posted on a medical pre-print website last week before it was peer-reviewed, and attracted much attention, including some criticism from scientists who said that it may have overstated the airborne threat. The virus is predominantly transmitted by respiratory droplets and in this form it is viable for only a few seconds after a person coughs or sneezes. Critics questioned whether a nebuliser accurately mimicked a human cough or sneeze.

The team behind the NEJM study performed similar tests on the SARS virus, finding the two viruses behave similarly. But their similar viability fails to explain why the novel coronavirus pandemic has infected close to 200,000 people and caused almost 8,000 deaths, while the SARS epidemic infected about 8,000 and killed nearly 800.

"This indicates that differences in the epidemiologic characteristics of these viruses probably arise from other factors, including high viral loads in the upper respiratory tract and the potential for persons infected with SARS-CoV-2 to shed and transmit the virus while asymptomatic," wrote the researchers.

SARS-CoV-2 is the technical name for the new coronavirus. The findings affirm guidance from public health professionals regarding social distancing, avoiding touching the face, covering your cough or sneeze, and frequently disinfecting objects using cleaning sprays or wipes.