“The CDC has established that the risk of surface transmission is low and secondary to primary routes of virus transmission through direct contact drops and aerosols,” said Vincent Hill, head of the Water Disease Prevention Branch, in a CDC-sponsored telephone briefing. .
Hill said the risk of transmission by touching a surface, although small, is high inside. Outdoors, the sun and other factors can kill viruses, Hill said.
The virus dies “quickly” on porous surfaces, but can persist longer on hard, inner surfaces.
Research has also suggested that surface transmission was more likely in the first 24 hours after a person became infected and that households where a person had Covid-19 had lower transmission rates when the household had cleaned and disinfected surfaces.
“In most cases, cleaning surfaces using soap or detergent, not disinfection, is enough to reduce the already low risk of transmitting the virus through surfaces,” Hill said. “Disinfection of surfaces is not usually necessary unless a person sick or someone positive for Covid-19 has been in the home for the past 24 hours.”
Hill said cleaning should focus on areas with high contact, such as door handles and light switches.
Household cleaners are a danger
People may use household cleaners to protect themselves from Covid-19, but misuse can have dangerous consequences, Hill added.
Frequent cleaning and disinfection of surfaces can have a minimal impact on viral transmission and can contribute to “hygiene theater,” he added.
“Showing a show ‘to clean and disinfect’ can be used to give people a sense of security that they are protected from the virus, but it can be a false sense of security if other preventative measures, such as wearing masks, physical distancing and hand hygiene is not constantly achieved, “Hill said.
“It could also make people feel less need to engage in these other important preventative measures.”
Additional data show that disinfectants themselves may present a risk.
“Public inquiries indicate that some people may intentionally drink, inhale or spray their skin with disinfectants without understanding that using disinfectants in this way can cause serious harm to their body,” he said.
Hill cited the June 2020 CDC research that shows that, of those people surveyed, “only 58% knew that bleach should not be mixed with ammonia, because mixing bleach and ammonia creates a toxic gas that harms people’s lungs.”
And the bleach itself can be harmful.
“Nineteen percent wash foods with bleach, which could lead to their consumption of unwashed bleach, which can damage the body because the bleach is toxic. Eighteen percent used a household cleanser on the skin. empty, which can damage the skin and cause rashes and burns, “Hill said.
Hill added that surveillance data show that the volume of calls to poisoning centers in 2020 for disinfectants was higher than in 2018 or 2019.
Alternative disinfection methods can also be a waste of time or even risky, says the CDC in the updated guide.
“The effectiveness of alternative methods of surface disinfection, such as ultrasonic waves, high-intensity UV radiation and blue LED light against the virus that causes COVID-19, has not been fully established,” the CDC says on its updated website.