Airborne COVID-19: Face masking important in control
Emerging evidence that COVID-19 could be airborne presents a red flag, as this latest finding makes it imperative that face masking is indeed one of the most important factors in the control of the pandemic. Prof. Titus Ibekwe, Head, Department of Otorhinolaryngology, University of Abuja and Faculty Secretary, ORLHNS National Postgraduate Medical College of Nigeria and immediate-past Vice Chairman International Advisory Board of the American Academy of Otorhinolaryngology Head and Neck Surgery (ORLHNS), spoke to NKECHI ONYEDIKA-UGOEZE in Abuja on this and other issues.
What is your take on the emerging evidence that COVID-19 could be airborne?
We can describe this virus as an enigma, because up till now, even the World Health Organisation (WHO) is not 100 percent sure of all its features. It is an evolving disease and that is why some people feel that there is discordance in the policies coming from the apex global health body. We should realise that this is a disease that is just slightly above seven months old and in the scientific world, a lot of information is still coming up. Initially, when the virus began, part of the information from WHO was that aerosol transmission, otherwise known as airborne transmission, was not likely because of the size of the particle.
It was believed that the particle belongs to the large particle size rather than the small particulates. This is because when you talk of airborne transmission, which is aerosol or droplets, the only difference is the size of particle concerned. When it is large particles that are being discharged to the environment from our speech or inhalation, you start talking of droplets, because the implication is that it cannot travel wide and not longer than two metres from the individual discharging it, because it cannot float in the air, but drops. When that size is a lot smaller, the tendency is that it will float and hang in the air and travel a long distance. But we know there are some other environmental factors that also create a balance between these two that make a difference.
The first is the temperature of the environment, second is humidity of the environment and the third is the issue of enclosure. When you have an enclosed space where humidity is low with very high temperature, the tendency is that what you may call a droplet may have the tendency to float. Droplets are basically wet aerosols and have a lot of fluid that comes along with it that will not allow it to float, but because of these conditions, it can easily dry up. The fourth one is the air current. So, when these factors are favourable, what we refer to as droplets may easily be converted to aerosol and we start talking of airborne. Today, diseases like tuberculosis, chicken pox and measles are typical infections that are airborne, because the particles are very small, so they float in the air and that is why they are very contagious when compared to whooping cough and COVID-19, whose particles are a lot heavier.
That is why WHO came out with that pronouncement initially that they are not airborne, but we know that these factors I mentioned earlier can even convert something that was meant to be non-aerosolised to become aerosolised in the process and once it gets aerosolised, that means it could be airborne. Over 200 researchers across the world wrote a letter to WHO, requesting it to review the situation again, because from their individual findings, it is likely that within an environment where all these factors could come into play, what we thought wasn’t airborne could be. The popular example in New York amongst some choir members that stayed in an enclosed space practicing, one person transmitted it to the others. Also, recently in China, there was a restaurant where a single person had it and the air conditioner was able to circulate it to everybody, despite the fact that they observed two metres physical distancing. Evidence abounds now that it is possible this disease can be transmitted through this means and bearing this in mind, it presents a red flag. This latest finding makes it imperative that face masking is indeed one of the most important factors in the control of this disease. That is why WHO is coming out to clarify that what they thought could not happen this way is actually possible and even more dangerous to the entire world that one can easily come out and pick in the air when an individual pollutes the air or environment.
What is the implication of this new finding?
It portends that every one of us has to be alert; we can’t afford to be complacent. We have to be more careful now than we were before and bearing in mind that there is no treatment yet, despite all the advancement made, and there is no vaccine. We all depend on preventive measures, which are not so difficult to abide by. You will recall that initially, the same WHO, based on the earlier mantra, thought that masks may not be necessary if you are not in an environment where you have somebody who is actively sick, but now we know that masks are important for everyone once you are outdoors, because now it is possible that it is airborne. Once everyone masks when outside, the tendency is that you will protect yourself from picking it up and also protect the next person, so you don’t pollute the air.
What does this portend for the transport sector, especially when people travel on the same aircraft, vehicles or boats?
What you have painted is what we refer to as enclosure. The chances of spreading COVID-19 are higher in an enclosure when compared to an open environment. That is why we advise those traveling in buses or vehicles to leave the windows open for cross-ventilation, but we know this is not possible in an aircraft, as you cannot open the windows. But you have air purifiers, air streamers and air filters within the aircraft which the Nigerian aviation authority has said can turn around the air several times rapidly and filter out the air within the aircraft, while the air conditioner replenishes with another. There is the air conditioner that pumps in air and there is another purifier that pumps out air several times within a minute. It is believed that this safety measure within an aircraft will help, but even at that, passengers must insist that to some reasonable level, physical distancing has to be maintained and those inside the aircraft must also use masks. This is why airline operators must not carry full capacity for any reason.
Every aircraft has to check and recheck this safety measure of filtration methods and it has to be part of quality assurance to ensure that things work very well. Sanitisers must be readily available, especially close to where you have the toilets, because passengers use them often. Movement in the aircraft has to be limited; it has already been suggested that moving around, sharing food must stop for now, but if you must, you can distribute these things while they are waiting to board. If these are observed, I think within the aircraft should be safe and the shorter the flight, the better. Thankfully, the maximum flight from any point to any point in Nigeria does not surpass two hours, even if you are going to the farthest part of the country. Nobody is more important than the other; we Nigerians are fond of throwing our weight around, insisting that we will not subject ourselves to safety protocols put in place.
Anybody who is not ready to abide by the simple rules that have been laid out should not be allowed to fly. All safety measures must be adhered to. Also, turnaround decontamination of the environment within the airports has to be very regular and everybody should wear their masks. If we do these, which of course are not easy by any means, we could be fine, but if we fail, it spells doom. There should be nothing like cutting measures to satisfy certain individuals. The same thing goes with land transporters, they have to limit the number of people they carry and must not carry full load. They must maintain some distance and all the windows must be open, because of the possibility of transmission through air conditioner in an enclosure. You don’t want to be in an enclosed space as much as possible, allow for free movement of air and shorten your distance and contact period. Government has already lifted the ban on interstate travel. We cannot be on lockdown forever, lockdown is not an end on its own; it is only a means to an end. You are just trying to stagnate the disease and reduce the rate of transmission while you get your arsenals ready, such as your medical team and procedures to attack the disease.
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