New Delhi: The US Centers for Disease Control and Prevention (CDC) has suggested that the Covid-19 virus is unlikely to spread through surfaces and animals, revising its earlier stance on the matter.
The disease surveillance agency updated its guidelines on ‘How Covid-19 Spreads’ on its website without any announcement earlier this week.
The revised guidelines states that the “virus spreads easily between people“. A new headline further states that it doesn’t spread easily in other ways, including “from touching surfaces or objects”, “from animals to people” and “from people to animals”.
CDC spokesperson Kristen Nordlund told The Washington Post that the revisions resulted from an internal review and “usability testing”. However, back in March the CDC had said that it “may be possible” for the virus to be transmitted through a contaminated surface.
The possibility of transmission of the virus from inanimate surfaces to humans, known as fomite-based transmission, has been a cause for much panic and worry.
Nordlund clarified by saying that the CDC’s “transmission language has not changed” and “Covid-19 spreads mainly through close contact from person to person”.
The change comes as the US eases the lockdown in all 50 states.
What research shows
Amid discussions over ways in which one could become infected, the Narendra Modi government put out extensive guidelines on disinfecting common public places, including offices. These guidelines state that the novel coronavirus “survives on environmental surfaces for a varied period of time”.
Three studies have played a major role in shaping the perception that Covid-19 can spread by contact with an “infected” surface.
The first — a study titled ‘Aerosol and Surface Stability of SARS-CoV-2 as Compared with SARS-CoV-1’— was published in the New England Journal of Medicine in March. According to this study by scientists from the National Institutes of Health (NIH), CDC, University of California, Los Angeles (UCLA), and Princeton University, the virus can live on surfaces like plastics and stainless steel for upto three days and on cardboard surfaces for upto 24 hours.
The second study was published just a few days later by the CDC which studied the spread of the virus through surfaces in the Diamond Princess cruise ship. Over 700 of the ship’s 3,711 passengers had been diagnosed with the infection in February, resulting in it being quarantined in Japan’s Yokahama for several days. The report found that there were still traces of the Covid-19 virus inside the ship even 17 days after all the passengers and crew were removed.
The third study came out in April and was conducted by researchers at the University of Hong Kong (HKU). Titled ‘Stability of SARS-CoV-2 in different environmental conditions’, it reported that traces of the virus was found on glass and banknotes for upto four days and on stainless steel and plastic for five days. Moreover, the virus also survived on masks for a week, as per the study.