'Early Testing Important To Control The Spread of Omicron'

As new cases of Covid-19 surge across India due to the new Omicron variant, we ask public health expert Vineeta Bal and chest surgeon Arvind Kumar what India's testing strategy should be

Early Testing Important To Control The Spread of Omicron

Mumbai: The number of daily new Covid-19 cases in India in the ongoing third wave is rising and crossing 268,000 on January 14, 2022. There are very early signs that cases may start plateauing in some cities, including in Mumbai. Many have contracted Covid-19, whether or not they're vaccinated. What is the progression of the Covid-19 disease in this wave? To what extent should we continue to be on guard? Given that in some cities, including in Mumbai, more than 80% of those who are tested through the more robust RT-PCR method are asymptomatic, what should India's testing strategy be?

To discuss this, we spoke with Arvind Kumar, chairman of the Institute of Chest Surgery, Chest Onco Surgery and Lung Transplantation at Medanta, Delhi and also founder of the Lung Care Foundation. We also spoke with Vineeta Bal, immunologist and faculty at the Indian Institute of Science Education and Research, Pune and a former scientist at the National Institute of Immunology.

Edited excerpts from the interview:

What is the progression of the Covid-19 disease, including with the Omicron variant, during this wave?

AK: With regard to the third wave, two-three things are very clear. One, that the Omicron variant which is responsible for this current Covid-19 wave is many times more infectious than the earlier Delta variant. Unlike last year, if one family member gets it now, rest assured that all other family members are getting infected. In my own department, one person got infected and almost everybody in the department got it. So it's highly infectious. That's why case numbers are rising so fast. Two, Omicron is escaping vaccines far more than previous variants had done.

Three, per data available till now, the disease seems to be milder compared to the Delta wave, where many more people were experiencing lung involvement and [reduced] oxygen [levels], which seems to be less common now. It's not that this is not being seen. Hospitalisations are happening, there are Covid-19 patients needing oxygen and ventilator support, but the percentage of such patients seems to be much lower.

Lastly, Mumbai's municipal corporation has released data that show that of about 2,000 people currently on oxygen across various hospitals in Mumbai due to Covid-19, 96% are unvaccinated. So, if you are vaccinated, Omicron is infecting you, but it's causing mild disease.

There have been some reports that Omicron affects the upper respiratory tract more, rather than the lungs. Looking at patients presently experiencing severe disease and needing intensive care and oxygen support for various reasons like having comorbidities or being unvaccinated, is the virus behaving any differently from before?

AK: Yes. As I said, the disease overall seems to be taking a less virulent course this time. Last year, we saw a lot of young people in their thirties without any comorbidities getting affected. Within a few days, the lungs got affected, oxygen levels started going down, ventilator support was needed and they had a very rapid downhill course. Compared to that, this time those problems are being seen in unvaccinated people and elderly people with multiple comorbidities. And even in these patients, the course seems to be comparatively milder compared to what we saw last year.

So the lungs are not as impacted, relatively, and therefore chances of recovery are much better overall?

AK: I'll give you an example. Last year, suppose there were 10 people who would reach out to me saying that they are Covid-19 positive. I knew that at least four of them would be saying in a day or two that their oxygen levels were getting affected, and we would have to arrange [hospital] beds for them. This time, there are a large number of people who are contacting us, and we are telling them to get their oxygen level tested because that's routine. Most are reporting that their oxygen level and breath-holding time is normal. We are not advising CT scans at all this year. Even D-dimer and [C-reactive Protein Blood] level tests are more often turning out to be normal this time, compared to last year.

So is the disease not progressing as dangerously as it was earlier? If it's going through the same path, via the throat or respiratory tract into the lungs, but having limited impact, could we, therefore, conclude that it's a less dangerous situation, and we don't have to worry so much?

AK: No, I won't say that. The reason is that the percentage of people who are getting this kind of serious infection is low compared to last year. However, the infectious nature of the virus this time is much more. Therefore, I have been saying on all television channels and all other media that we should not have the impression that it's a mild disease.

Many people have said that [Omicron] is a flu-like syndrome, and we should embrace it like the flu and let everybody get affected and be done with it. No, I won't take that approach. Because even if the number of people who are getting serious disease is small, when the denominator is massive, if crores of people get affected, even that small number will overwhelm the health system and will lead to a large number of [deaths].

So let's not mistake [Omicron] as the common flu or something that we need to embrace. No, it's a serious Covid-19 infection. Yes, it's not as deadly as the Delta variant. However, it is causing hospitalisations and death. Also, you never know when the next variation [in disease progression] may come. Therefore, we need to take it very seriously.

Dr Bal, how should India approach Covid-19 testing? What would be a more effective public health response to a virus which is so now prevalent among us?

VB: One has to worry about how well the virus is spreading. Diagnosis is important, in principle. If our healthcare system was very well equipped, if we had all the infrastructure in place and if we had a lot of money, it would have been ideal to test everybody in the community. If there is one RT-PCR or Rapid Antigen-positive in a family, ideally everybody else in the family should be tested and then further steps taken, but we know very well how poor our infrastructure is, despite the fact that we are better prepared compared to the Delta [wave].

In terms of diagnostic facilities or oxygen availability, ICU beds, all of this is better now, compared to last March before the Delta wave occurred. Despite that, is there really any point in spending so much money on diagnosing the last person who is Omicron positive today, when we still don't have enough money? What we are going to do is isolation, essentially, as many more are getting infected but very few people need hospitalisation. So, infected people will keep spreading the infection to others, but most of them will not need hospitalisation. In such a situation, just labelling somebody Omicron-positive or otherwise makes somewhat less sense. I'm talking about the non-ideal, non-optimal situation in which we are living. There is no denying that. I wouldn't have said this if we were living in the United States or the United Kingdom. So now, I think the focus should be on every symptomatic individual because it is symptomatic people who are likely to deteriorate further.

Last time, when the Delta wave was at its peak, there were 400,000 [daily] cases in the country. Now, numbers may go even beyond that. But in every city, as you have seen in Kolkata and in Delhi, the absolute numbers getting infected every day has gone up, but despite that, hospital admissions are down. So, the numbers may increase phenomenally and that is why we should worry less about diagnosing every individual and focus a lot more on how their progression to severe disease is halted.

For that, there are different ways of looking at it. First, I wouldn't like to call this a wave yet even today, because as we saw last time as well, cases started going up in Mumbai, but now appear to be stabilising, while cases in Delhi are still going up. So big metropolises where international flights arrived and where the virus got introduced [early], those are coming down in terms of numbers of cases. But if you look at other places, now Uttar Pradesh and Madhya Pradesh are slowly picking up.

This is going to be a factor, that there will be different parts which are getting affected today, some other parts will start getting affected from tomorrow. So it's not a single wave in which cases will rise and fall smoothly. That's not going to be the case, which is, in a sense, beneficial because cases will fall in Mumbai and Delhi, then maybe in Faridabad or Noida or Lucknow so there is a possibility of diverting our resources if we need to. In that sense, we are not following actions to decrease the spread. What the government hasn't done, what we have not managed to do, for example, is manufacture and make N95 masks available to everyone. In earlier waves, N95 masks were a very precious commodity. But we had two years to manufacture N95 masks if we wanted to, if we had thought about it. If people wear N95 masks meticulously, then the chances of spread will be low.

Dr Kumar, Dr Bal's point is that it does not make sense to have a very high level of testing, particularly for asymptomatic patients. Would you concur?

AK: From a logistics point of view, I totally agree that when case numbers get massive, our infrastructure is not going to be capable or able to deal with these numbers. Somebody asked me this question a couple of days back: 'Why should we do testing? Everybody should be presumed to be positive and let's just take precaution'. My answer to them was, if I tell you that you are likely to be positive, and on the other hand I give you an RT-PCR report which says you are positive, in which of these two situations do I expect better isolation from you? Obviously, when you know that you are RT-PCR positive.

We know that people isolating themselves, using N95 masks, and practising social distancing are our best methods to prevent the transmission of Covid-19. Ultimately, it boils down to preventing the transmission of disease, not just for managing numbers, but also for managing mutations. Mutations are also going to occur more frequently if cases go on rising, because when that many copies of the virus are being produced, you're likely to have more mutations. Therefore, we need to cut down the case numbers and for that, these preventive strategies are important. From that angle, I feel testing and labelling the person Covid-19 positive has a psychological impact and ensures better compliance.

The flip side of that psychological impact, unfortunately, at least in Mumbai, is that people are petrified of being visited by the BMC. The fear is that once your name and number are recorded in the system, you don't know when they're going to land up at your house, seal your flat, your building, and cause a lot of disruption to your life and other people's lives if you live in an apartment complex. That's something you don't want, apart from the stigma which was a problem more acutely felt in the first and second waves. So, how do we balance these two situations?

AK: I think we need to test. There is no denying the fact that we need to test. Suppose somebody visits a family and six family members are exposed. One of them becomes symptomatic. I don't think we'll be able to lay down a clear cut golden rule whether you test that one person or you test the entire family, because ultimately this will vary by situation. Ideally, if facilities are available, we must test. But if facilities are not available, we will have to manage with less testing.

VB: I agree that this kind of testing is important, in principle, but my perspective was more from an 'outside the hospital' public health perspective. I was also harping on physical distancing and masking, but we are a society where we do not want to follow the rules. Sometimes it is also impossible [to ensure]. For example, the point about N95 mask unavailability that I was raising earlier. So, how do you think of controlling infection?

I understand that there are so-called rapid antigen test equivalents available now, which will be used by people who can afford them, people who have smartphones. We are talking about a different stratum of society where such tests will be used. People who are likely to think 'I know better, rather than getting into the clutches of the BMC, I will do the test myself and if I'm positive, I will isolate myself'. This is likely to happen because tests are becoming available in large numbers and Rs 200-300 is affordable for many people from a certain stratum of society. So the people staying in multi-storey apartments are the ones who will use these tests. Those in 'Bombay' as opposed to 'Mumbai', as in the India versus Bharat comparison.

I don't think there is any way in which we can actually just stop transmission. This infection will spread from major cities to smaller cities, the way it happened during the Delta wave. In the northeast, for example, in Manipur or Nagaland, the cases of Delta positivity were coming up in November and December when in Mumbai, for example, after July-August, there was practically no serious increase in numbers. So we are going through this spread of infection all through the country because, for mainly economic reasons, we cannot afford to stop activity the way it was stopped in the first wave for sure. The first wave was pretty bad, when there were draconian measures with very few cases. In the second wave also, we had to follow instructions. Now too, there are restrictions. But we are not the kind, as a society, who can follow instructions. Also, imagine if I have to use public transport to go to work, I have no choice but to get into that crowded bus or suburban train. In such a situation for people who are middle class, lower middle class and poor, there is no stopping their going wherever they want to make a living. In that sense, the infection will spread. I would not call it a disease because, as Dr Kumar was saying, disease incidence is very, very low.

My worry is related to the hospitals. In the second Delta wave, there was hardly any infrastructure available and there was a major outcry for oxygen, ICU beds, etc. Now, we have the capacity to go back at least to that level of infrastructure, but Omicron is so transmissible, so infectious. I read in the newspaper that 700 healthcare workers including from AIIMS, Delhi were infected. So I wonder whether we will have enough infrastructure, but will be short on manpower. The contractual manpower which was employed in jumbo Covid-19 care centres are likely to be brought in again. But if the infection is spreading so rapidly, are we going to sustain getting enough manpower to provide care? Or are we going to face a different kind of crisis: infrastructure but no trained manpower to look after the patient? I hope not, but I worry about that.

Dr Kumar, are there unvaccinated patients among those you've been treating? Why didn't people get vaccinated?

AK: There were numerous issues why vaccine hesitancy was there. Political issues, religious issues, misinformation and, I would say, a lot of information. There are a couple of very highly educated doctor friends I know--so educated that they decided that it's not prudent to get vaccinated. This is the other end of the spectrum--so over-educated that they refuse to see reason.

One thing which has emerged is that N95 masks are a very effective way of preventing the spread of this infection. Physical distancing is also very effective. Vaccination may not be an effective way of preventing infection with Omicron, but it's a very effective way of preventing yourself from getting moderate to severe disease and hospital admission.

Yesterday, there was a University of Bristol study which said that once Omicron comes out as an aerosol, if it's in the air for 10 minutes, it loses 90% of its infectivity. Now, this is not peer-reviewed data, but if it ultimately turns out to be true, it would actually give us a very clear-cut indication. I would like to share an anecdote, that I have seen people in offices, who otherwise wear masks all the time, remove the mask when they want to have tea or lunch together. I think these are the biggest superspreader events, because in those 5-10 minutes that you are without a mask, if one out of 10 people sitting together for lunch around the table is positive, I think everybody will become positive. This is a message I would like to give to all readers that as long as Covid-19 is around, not only should you wear a mask, please keep the mask on if even one more person is in the room. Remove the mask only when you're alone and do not have tea, lunch, etc. together in the office. These might prove to be superspreader events.

Should India invest in more infrastructure for RT-PCR and RAT tests, for the public health system to learn where cases are rising? Should people be taking them more frequently and not shying away from them?

AK: I discussed this issue about RAT test versus RT-PCR, and the view was that RAT has very low sensitivity, to the tune of about 50%. So if it's positive, it's fine. But if it's negative, you could still be positive, and then you take an RT-PCR. So essentially, 50% of the people will end up having two tests done, first RAT and then RT-PCR, which might be actually straining the infrastructure more than if people were only going for RT PCR. If it's a home RAT test available easily, it's okay. But in a healthcare setting, straight away doing RT-PCR to my mind is a better option.

The prime minister urged chief ministers just a day ago to focus on ensuring that the economy continues to run, which means people must have mobility and are able to work. In this larger context, in which we try and live with Covid-19, do you feel we need to step up testing capacity and be mentally prepared to be constantly tested?

AK: I would say that vaccination, preventing transmission by effective use of N95 masks, physical distancing and testing as and when needed will be the strategy going forward, because this virus is going to be there with us for some time, and we obviously have to continue with our life, with economic activity.

VB: I broadly agree. There isn't anything much that we can do about physical distancing. In a country like ours, physical distancing is close to impossible for probably more than 70% of the people. So, that is something that we have to live with. As I was saying earlier, I may have no choice but to travel in a Mumbai suburban train, because a Virar to Churchgate 80-km distance cannot be covered in any other way that is affordable. That is something that we have to live with.

So there will be small and frequent outbreaks in different locations, which we will have to deal with. And for those outbreaks to be identified and people infected to be identified, the RAT tests are useful. I still feel that especially in the home situation or in an office situation where there was exposure and an outbreak, if such rapid tests can be conducted without going to the RT-PCR facility, that itself decreases the load. Even if it is a 50% decrease, that is worthwhile. Because everybody going for RT-PCR is going to paralyse the laboratory system again. So the tests should be made more available.

There is a clause and an appeal that everybody who uses home tests should upload the results so that we know how many are positive, how many are negative. Unfortunately, I'm very pessimistic about that. I don't think this is going to happen. We do not have control over even the regular data from lab testing, and there are many, many gaps in our data collection. So if there are home tests happening, I do see that there will be many more positive and negative results that will be missed out.

But I think that is less important as long as people understand that if the RAT test is positive, isolation is a must. Fortunately, this virus, because it lives in the upper respiratory tract, even when people are sick, they normally get well in 2-4 days, rather than 7-10 days. So isolation of about 6-7 days, and not 14 as was recommended for Delta, is also a useful measure. These small measures in different locations, if implemented very effectively, will be adequate.

Beyond that, if we are going to live with the virus, we have to get vaccination done. We have to reach those who haven't gotten vaccinated. The new vaccines should also be made available to avoid the current shortage that we are facing again. Covaxin is not available because it's also being provided for the 15 to 18 age group. We need vaccines for the lower age group. All of that should be seriously attended to.

Dr Kumar, people are going to gamble on this. If I maybe have some symptoms, I may self-test and not go for an RT-PCR test. I may have symptoms and do neither self-test or RT-PCR. What is the cutoff point when people should stop taking chances and get themselves tested, or visit their physician?

In the last 15 days, there are at least 10 people who I met in the hospital and when I talked to them, they were trying to clear their throat. I asked what is happening and they said since the previous evening, they had a slight sore throat, but no fever or anything. And I said, go get yourself tested now. I forced them to go and all of them turned out positive. So, this time, Omicron is not starting with fever. In a lot of people, it's starting with just a scratchy or sore throat or headache or running nose. Since this is also flu and viral fever season, when all of us get the common cold, a lot of people mistook Omicron infection to be the common cold. Now that people know about Omicron, people are getting tested. So, therefore, I think a high index of suspicion based on the trends and data of the time will have to be continued so that people are continuously informed that these may be the symptoms and therefore they should get tested. Because the worst thing is if somebody is positive and doesn't get tested and thus doesn't isolate himself, he actively continues to spread the disease. Therefore, I would say early testing will continue to be important.

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