After much delay, the World Health Organization (WHO) has finally recognized the aerosol or airborne transmission of COVID-19 and it has updated this in its latest brief on 30th April 2021.
Aerosol is small but airborne matter produced by sneezing, coughing or even talking people which can remain suspended in the air for a long time and carry the COVID-19 virus.
The WHO website on the section about how COVID-19 spreads now has an additional point that says, “The virus can also spread in poorly ventilated and/or crowded indoor settings, where people tend to spend longer periods of time. This is because aerosols remain suspended in the air or travel farther than 1 meter (long-range).”
Until now the official stance of the WHO was that the virus was spread mainly through heavy droplets that was pulled down by gravity and hence the 1-meter rule or fomite transmission which is respiratory secretions or droplets contaminating surfaces and hence the hand washing rule.
However, a growing body of research and calls from scientists and researches showed the virus can also be carried by fine aerosol that is airborne and travels well beyond 1 meter. It can also stay in the air for a longer period. A recent paper in the Lancet also pointed to 10 streams of evidence in this count.
For Bhutan this update in the WHO advisory is already leading to some changes in protocols for high risk areas.
Quarantine protocols under focus
The Health Minister Dasho Dechen Wangmo said, “Just now our risk is from the quarantine facilities. We are looking at how people will stay in quarantine, how and where they will get tested and in line with the airborne nature of the virus the type of ventilation in quarantine centers.”
Lyonpo said that an assessment was being done of quarantine centers in all the throms like Phuentsholing and others in light of this.
The minister said the second issue is looking at the risks to frontliners, and therefore there is a review of the PPE including appropriate wear while attending to those in quarantine.
Lyonpo said the third area is the arrival of foreign workers at the gate and how they are to be screened and how they will be transported, including providing PPE for frontliners.
She said the isolation ward of the hospital is not a problem as the medical staff there already wear adequate PPE.
She also pointed out that those staying in quarantine facilities will now be classified into the normal and high risk group.
Lyonpo stressed that quarantine facilities must now have proper ventilation including in the rooms especially for the high risk group including PPE.
The minister said that it has also been decided that the high risk individuals will not stay in quarantine centers which are in the middle of the city in crowded places. Instead they would be isolated at a distance.
Lyonpo said that they are also relooking at revisiting all health protocols in health facilities, flu clinics, emergency and isolation.
However, Lyonpo said that the above is being done not just in the light of the new advice from the WHO, but also due to their own learnings from every lockdown. “We are learning and revisiting our protocols,” said Lyonpo.
Schools and Offices
When asked about advice or protocols for schools, Lyonpo said that is there is no major shift in recommendations for people living in close quarters as the only way risk reduction can be done is through the surveillance system that has been put in place.
She said this system in school detects sick children, but Lyonpo also called upon parents to not send children to school if they are sick and to test the student and also get the family tested. She said that a person may be vaccinated but that person can still be a carrier.
Lyonpo said that as per earlier advice schools are already supposed to ensure ventilation and aerate the room.
She said the recent government advice on cancelling all meetings above 25 minutes is also related to this. Lyonpo said that her ministry has cancelled all meetings.
The minister said the earlier guidelines had called for proper ventilation in government offices and it must be followed. She said that vulnerable people must be allowed to work from home and the risk of exposure must be reduced.
Recently a significant number of frontline workers have tested positive while on quarantine duty, especially in Phuentsholing. This has raised the question of if the aerosol from those in quarantine must have turned these frontliners positive.
Lyonpo said, “The possibility is there because you see if you are in a closed corridor and everybody opens their room door then the virus could be floating in the alley and frontliners have to do certain tasks.”
However, Lyonpo also said it is difficult to directly attribute the infection of frontliners to this as desuups in the line of duty have to attend to those in quarantine and while doing so there is some contact.
The WHO’s acknowledgement of the airborne nature of COVID-19 may finally give a clue to the origin of the three outbreaks in Bhutan so far.
The first outbreak last year happened around the MDP area where protocols had been followed and distance had been maintained from Indian drivers but MDP staff still got infected.
The source of the second outbreak according to the government is most likely to be a 27th November 2020 flight when the majority of the passengers who were referral patients and some customs officials turned positive. Here too, the role of aerosol infecting passengers in the flight now cannot be ruled out.
After the first two outbreaks the protocols had been significantly strengthened both in Paro and Thimphu and also in Phuentsholing.
However, despite this a third outbreak occurred in Phuentsholing and this time even frontliners on duty turned positive. The aerosol route of infection both within the quarantine hotels and also outside it, given the location of theses hotels in the middle of a crowded town cannot be ruled out.
Thimphu also got a scare when two staff at a hotel in Lanjophakha with some positive referral patients turned positive and one of them had broken protocol to play cricket. Here too the role of aerosol in the two staff turning positive cannot be ruled out.
Slow footed WHO
However, the fact that COVID-19 spreads through aerosol was not completely unknown as early in the pandemic last year there were studies from all over the world pointing to this including even examples in hospitals in Wuhan, China.
A Massachusetts Institute of Technology (MIT) study in fact showed how aerosol from a simple cough or sneeze travelled so much farther than one meter.
Japanese public broadcaster NHK and some researches using special cameras showed aerosol generation even while talking and how it hung around a poorly ventilated room for a long time.
This paper even raised the above studies and asked the MoH in a press conference on if it was considering the above data, but the MoH made it clear at the time that it was going by WHO advice.
In July 2020, 239 scientists jointly issued an open letter asking for the medical community and international bodies to recognize the risk of aerosol or airborne transmission of COVID-19.
The WHO in July 2020 said that short range aerosol transmission in crowded indoor locations cannot be ruled out.
However, this was still waffling and despite a growing body of data and evidence the WHO took its time to review it as cases spread like wildfire across the world. It was only on 30th April 2021 that WHO officially recognized aerosol transmission.
As with the WHO initially advocating only those with symptoms wear face masks WHO has shown itself to be slow footed and heavily bureaucratic in recognizing the credible and new science around a fast moving pandemic.
Even now the WHO still maintains a defensive stance on the issue.
The paper contacted WHO Representative Dr Rui Paulo de Jesus to ask about the WHO’s new 30th April update on aerosol transmission on Thursday but Dr Rui asked the reporter to check back with him the next day as he needed to check.
On Friday Dr Rui claimed that WHO had always said that there is a higher risk in a closed door poorly ventilated and crowded room. He said the main source of infection is person to person in close proximity and guidelines like proper wearing of facemasks and ventilation should be followed.
However, Dr Rui’s claims are not entirely correct as the July 2020 advisory only used words like ‘possible’ and ‘may’ for airborne transmission and strongly focused on droplet and fomite transmission.
The impact of such WHO advice in a country like Bhutan is that hand washing and 1-meter gap is still the main messaging and advice with still not enough focus paid on ventilation and airflow.