Use masks indoors until you’re sure your family isn't infected: Gagandeep Kang
The government on Monday urged people to do more to break the chain of Covid-19 transmission with VK Paul, member (Health), Niti Aayog, saying people may need to wear masks even while they are at home. Gagandeep Kang, a virologist at Vellore’s Christian Medical College, spoke to Sunetra Choudhary about the need for wearing masks even indoors. Edited excerpts:
Is there a need to wear masks at home even if there is not a Covid-19 patient around?
The thing to think about is how are infections acquired. Infections are acquired when you have someone who is infected in your vicinity and that person is a source. When that person, speaks, eats, sings, breathes in and out, she will be putting out viral particles even with the new infectious variant for about a week to nine days. With the older version of the virus, we thought it was about a week--two days before symptoms and five days after. Now, what seems to be happening with the UK variant is that the amount of virus that is in the respiratory tract is quite a lot, much more than the ancestral variant. This means that a lot more virus is getting shed. In that situation, whenever you are around infected persons, it makes sense for them and you to mask so that you are each protecting the other. Should you be masking at home? If you are in contact with people that you do not know whether they are infected or not, it makes sense to stay masked. Should you stay masked inside with people you know who have not been exposed to anybody infected? I am not sure what level of risk that has and whether in that situation also you should be masked up.
Watch: Everything you want to know about masks, explained by Dr Gagandeep Kang
So, if people want to err on the side of caution, they can choose to wear the mask...
A lot of infection happens when you are asymptomatic. So, if anyone in your family has been in contact with other people who might be potentially infectious and you want to be sure that they have not really brought the infection home, then it makes sense to stay with a mask until you are sure that your family members have not been infected during the time they were in contact with others. This applies at a time when there is very high transmission outside and you are really worried about the risk. Once the risk settles down and you have less transmission in Delhi, then it might be time to rethink the intensive wearing of masks at home.
Is masking a good idea in homes where someone is going out to work?
At this time, there is a very high risk in places like Delhi that a person going outside is going to come in contact with people whose infection status is unknown. Anytime that happens, you should be treating that person as a potentially infectious contact. If you want to be really careful, that is good advice to follow at this time.
The other thing is should you be following the same when everyone is vaccinated? In other parts of the world, the [The United States] CDC [Centers for Disease Control and Prevention] for example, says if everybody in the family is vaccinated, then it is safe for you to be around each other without masks. If there is an incentive to get vaccinated, that is it.
Can you say definitively now that cloth masks are not enough and N95 are required?
I think N95 masks are expensive and a luxury. N95 masks without valves are the safest protection that you can have. It is very important that with the N95 or the surgical mask, you wear them well. If for example, your glasses are steaming up on top of the mask, you are not wearing it well as air is coming out from the mask. The order is N95 masks for any situation that is a high risk, three-layered good surgical masks for most other interactions. I would advise that you use...[cloth masks in Delhi] only to make sure the surgical mask is fitting as well as possible.
The doubts about masks began following a study about the coronavirus being airborne. What does that mean?
The virus has always been airborne as it is a respiratory virus. So, it is a virus that comes out of your track in a range of particle sizes. You can have very small particles and you can have very large ones. Originally when we first heard about the virus, we were not sure there was human to human transmission. When we knew there was, we knew it was due to droplet infections. ...when you breathe out, ...large particle size...settles in an area around you approximately 3-6 feet. ...We now know that it is not only droplets. It is also aerosol that is generated, smaller than the 5-micron cut off. If those particles are that small, they have the ability to float around in the air for a lot longer. So, if you are in an enclosed space with an infected person, those particles will build up over time. So, ventilation is good because it creates an airflow that dilutes the particles out. So how can a person be infected if they have never been near an infectious person? There are two ways. One, you did not know that someone was infected, and they came home. If you live with young people, they may have an asymptomatic infection that was never picked up but was infectious enough to infect an older, susceptible person. The other one that has been hypothesized but not yet proven is that when you have a droplet infection and droplets fall all around you, when you clean after that, those droplets can become an aerosol which can float around for a while and infect someone else. The latter theory sounds a little less clear to me. It has been shown in experimental systems... but for humans, there is no data that backs that.
Could the current situation of oxygen shortage have been avoided?
It is difficult to assess. Obviously, we do not have as much oxygen as needed in the worst-hit places at this time. In terms of logistics for establishing new infrastructure, could we have been faster? We could always have been. Did we not do the right thing? I do not think anybody was anticipating a surge of this size. Should we have looked at other countries and predicted this? We did not even though there have been second waves in other places. The behaviour of viruses is difficult to predict. What is happening now, I hope this will be a lesson to us for the future. That building up infrastructure which allows for surge capacity is always going to be a good investment.
Do you think our policymakers should have been working very hard from January to March when numbers were down? Did they get complacent?
I am working with a group that is seeking to develop a road map for health care in India. We really think that not just for these few months, both short term and long term, we need investments in health and primary health care. This happens time and again. Every time there is an emergency, certain issues get highlighted. As soon as the emergency is over, it is no longer an urgent need. It happened after the first wave. I hope it would not happen after the second.
What is the most important step the government can take right now?
I think urgent care outside of hospital facilities. So, if they do not have beds, then what is it that you can do to ready beds as soon as possible. Nobody should be left lying outside of a hospital.