Virus survives on steel, plastic for 3 days: Study
BREAKTHROUGH Sars-cov-2 virus is detectable for up to three hours in aerosols as well
NO VIABLE SARS-COV-2 (CORONAVIRUS) WAS MEASURED AFTER FOUR HOURS ON COPPER AND AFTER 24 HOURS ON CARDBOARD, THE PEERREVIEWED STUDY FOUND
NEWDELHI: The novel coronavirus that has killed about 8,000 and infected 200,000 people worldwide stays infectious in aerosols for several hours and on surfaces for days, says a breakthrough study that explains how the pathogen spreads quickly through infected droplets and from contact with contaminated surfaces.
Sars-cov-2, the virus that causes the Covid-19 disease, is detectable for up to three hours in aerosols, up to four hours on a copper surface, up to 24 hours on cardboard, and up to two-three days on plastic and stainless steel, the study published in the peer-reviewed New England Journal of Medicine (NEJM) found.
It compared the stability of Sars-cov-2 in the environment with that of Sars-cov, which caused the Severe Acute Respiratory Syndrome (Sars) outbreak that sickened close to 8,000 people in 2002-2003. Scientists say both viruses are closely related. No Sars case has been detected since 2004.
The study found that the stability, or the duration a virus is live in the environment, of SarsCOV-2 was similar to that of SarsCOV in experimental circumstances tested.
But unlike Sars, which was contained through intensive contact tracing and case isolation measures, the ongoing community transmission of Covid-19 in several countries has turned it into a pandemic.
Community transmission is when a person tests positive for the disease but doctors are not able to trace the source of the infection.
“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,”
A study published in the New England Journal of Medicine looked at the SARS-COV-2 (the coronavirus which is causing the pandemic at present) and SARS-COV-1 (which caused the Sars outbreak in 2002-2003), in five environmental conditions. Here’s how long the coronavirus stays infectious on the surfaces examined
DECODING THE STUDY
No infectious coronavirus was detected in aerosols/air after three hours, while infectious virus was detected on plastic for up to three days. Obviously, the rate of decay of the virus differed on these surfaces.
said the study published on Wednesday.
INFECTIOUS ON VARIOUS SURFACES
No viable Sars-cov-2 was measured after four hours and no viable Sars-cov was measured after eight hours on copper, the study noted. Further, on cardboard, no viable Sars-cov-2 was measured after 24 hours and no viable SarsCOV was measured after eight hours, indicating that the Sars virus did not last as long on these surfaces as the coronavirus.
The study warned of the dan
gers of Covid-19 spreading from people who do not have symptoms or those with mild symptoms, an occurrence confirmed in another study from China.
The earlier study published in the journal, Science, on Tuesday found that for every confirmed case in China, there are another five to 10 people in the community with mild, undetected symptoms. These undiagnosed cases were the source of 79% of reported infections in China before a lockdown was imposed on January 23.
Another difference between the two viruses is that Covid-19 is spreading in community settings, unlike Sars, which caused outbreaks in clusters in hospitals.
“If viral shedding is high, there will be higher concentration of aerosols in the air and on surfaces, which makes the risk of transmission higher in hospital settings compared to other groups,” said Dr G Anil K Prasad, professor and former head of respiratory virology at Vallabhai Patel Chest Institute, University of Delhi.
Viral shedding is the release of virus in the air or any surface by an infected person.
HEALTHCARE WORKERS MUST TAKE CARE
“Those in ICUS performing intubation on people with severe respiratory diseases are at particular risk and must wear N95 masks to filter out 95% of liquid or airborne particles,” he said.
Intubation is a procedure through which a tube is placed into a patient’s airways through the throat to assist with breathing.
The World Health Organization (WHO) is considering new “airborne precautions” for hospital staff.
“When you do an aerosol-generating procedure like in a medical care facility, you have the possibility to what we call aerosolize these particles, which means they can stay in the air a little bit longer. It’s very important that healthcare workers take additional precautions when they’re working on patients,” said Maria Van Kerkhove, head of WHO’S emerging diseases and zoonoses unit in Geneva.