KUALA LUMPUR, Feb 21 — An expert in infectious diseases said there is no proof that the novel coronavirus is airborne, following such a claim from a group of Chinese doctors in Shanghai.
“We have not proven that to be the case in most centres beyond this group in Shanghai, to be frank,” Dr Christopher Lee told a press conference at the Malaysian Medical Association (MMA) House.
On the contrary, current data shows that Covid-19 spreads through direct contact and touch either from person-to-person or through a contaminated inanimate object, as well as droplet spread.
The former Health deputy director-general in charge of research and technical support noted that droplet spread is not the same as airborne transmission, which is the method of transmission for tuberculosis (TB).
“If one of us in this room and this room is air-conditioned and we are not that far apart, if someone at the far end… is coughing away and you have active TB now in the lung, all of us… can be exposed.
“But if you have something like coronavirus, whether it’s SARS or whether it’s MERS or whether it’s now this new SARS-Covid, the new one — SARS-Covid 2, that’s the new virus — if you’re coughing from over there, the person who may be affected are people within one to two metres around here, depending how hard you cough.”
Airborne transmission, Dr Lee added, can take place within 10 to 20 feet, depending on the turbulence in the room, how much air is exchanged in the space, and if an air-conditioner is turned on.
“As you know, (with) air-conditioning, (the) air is kept in the room, isn’t it? And that’s not good. So, the air will circulate around.
“The difference is this: when it’s (a) droplet, when we are talking there will be micro…drops but this won’t stay in the air for long; it will drop to a common surface.
“So, all of us in our space around us when we talk, some of us talk, we spray more than others, there will be micro drops around here. So, this area around me will be contaminated by me.”
Air purifiers could filter out these particles, he added, based on the amount of filtering it can get done — such as those used for negative pressure rooms.
“In theory, it could help,” he said.
Dr Lee, meanwhile, said that the lifespan of the coronavirus could vary from a few hours to even days, depending on the ambient temperature, the level of humidity, and the type of surface that the droplets have fallen on.
“The warmer it is, the less likely it will survive longer,” he said. “So, I guess if you have coronavirus and you cough at me outside in the Sahara desert in the midday, it may not survive very long.
“But if you’re in the winter month in the UK and you cough and you have coronavirus, it may survive for hours, even days,” he said but clarified that Covid-19 is relatively new and the medical community does not have all the data about it.
Nevertheless, he noted that Covid-19 has links to the Severe Acute Respiratory Syndrome (SARS) coronavirus, which occurred during winter. By summer of the year of the SARS outbreak, it “just disappeared”.
“We would like to think that it’s because of the infection control and public health interventions, and I’m sure that they played a major role in controlling SARS, but I think the temperature, the summer months, also helped.”
Dr Lee said there are some epidemiologists and virologists are expecting to see a similar trend in temperate countries once their temperatures begin going up.
And in hot and humid Malaysia?
“We are a pretty hot place, so I guess if you’re outside, the risk will be much lower. But many of us now live in an air-conditioned room, so that is a risk,” Dr Lee explained.
“The temperature is more important than humidity, but both factors are important,” he added.
But Dr Lee clarified that using the air-conditioner was not all bad — it just depends on who you sleep with; if you’re sleeping alone, you can use an air-conditioner, and so long as you do not share a room with someone with the coronavirus.
“And if you’re forced to share a room, hopefully, that never happens, that has never happened in Malaysia, that person must wear a mask to make it safer for you. But that’s a hypothetical; that’s not something we recommend.”