Covid-19 can be spread through airborne transmissions, US public health agency says
Coronavirus can be spread through airborne transmission, as well as through coughs and sneezes, the US federal public health agency has said.
In a newly published report, the US Centers for Disease Control and Prevention said Covid-19 can be spread by tiny particles suspended in the air, sometimes for hours, but that this form of airborne transmission "appears uncommon".
Infected people who spent more than 30 minutes in an enclosed space were able to produce enough respiratory droplets to cause infections in people who were more than six feet away or who passed through that space soon after an infectious person had left.
Covid: Boris Johnson suggests need for social distancing will be over by 2021 Tory conference
Chance of catching Covid-19 from surfaces less than previously thought, scientists claim
Airborne transmission can also occur when there is prolonged exposure to respiratory particles, often generated through exertion, such as through singing, shouting or exercising.
Poorly ventilated areas also allowed for the build-up of droplets, the CDC said.
It added most coronavirus infections are spread through close contact with someone infected with Covid, such as through droplets in coughs and sneezes. Close contact refers to transmission which can happen through either contact or droplet transmission while a person is within six foot of an infected person.
The CDC has not issued any changes to how people can take measures to protect themselves.
The agency has reiterated the importance of social distancing, using masks, hand hygiene, cleaning surfaces, ventilation and avoiding crowded indoor spaces.
They said: "At this time, there is no indication of a general community need to use special engineering controls, such as those required to protect against airborne transmission of infections, like measles or tuberculosis, in the healthcare setting."
Last month, the US federal public health said it had mistakenly published a draft update to its recommendations on whether coronavirus could be spread through airborne particles, which was swiftly deleted.
The World Health Organisation (WHO) said in July there was "emerging evidence" for airborne transmission after 200 scientists wrote a letter compiling research carried out so far.
On Tuesday, additional research has found coronavirus may not be spread as widely through surfaces as previously thought.
Dr Andrew Preston, reader in Microbial Pathogenesis at the University of Bath, told ITV News: "More recently, there have been several articles questioning the relevance of these studies and suggesting risk from surfaces is low."
Transmission of the virus was much more likely from close contact between people indoor situations because the small droplets that travel from noses and mouths can go much further than the large droplets which can be left on surfaces, Dr Preston said.
He said just because the chance of catching the virus was low doesn't mean it should be ignored.
He pointed out it could still be a significant risk in some situations: "For example, a tube train carriage will have a high turnover of people.
"One of the poles or handles that people use could be touched by numerous people in a short space of time.
"So hand washing must remain a central part of the preventative measures against Covid."