Mumbai: Some patients presenting with gastrointestinal or ENT (ear-nose-throat) symptoms are also testing positive for COVID-19, Saibal Moitra, adjunct professor and senior consultant, Department of Allergy and Immunology at the Apollo Gleneagles Hospital, Kolkata, tells us in this interview. Every patient should be investigated for COVID-19, he says, to reduce unnecessary exposure to healthcare workers and the larger community.

The lower levels of testing in West Bengal are a concern, though the numbers have now risen, he says, adding that extensive testing is necessary for efficient classification of areas/districts into green, orange and red zones to help determine lockdown levels. As of May 3, West Bengal has tested 22,915 samples/people--252 tests per million, compared to the 865 nationwide. The state has 10 red zones, five orange zones and eight green zones.

Immunologically speaking, COVID-19 is an interesting disease, and measuring the levels of CD4 (white blood cells), cytokines and lymphocytes will help show which patients are likely to progress to a severe stage of the disease, he says.

Edited excerpts:

What kind of cases are being presented? And how are you responding?

The scenario here is pretty disturbing. I say disturbing because we are now getting all sorts of cases. It is not just the typical symptoms that we knew initially--[patients with symptoms] such as fever, cough and influenza-like illness, who are most likely to have COVID-19. We are now finding patients with protean manifestations. They may have gastrointestinal symptoms, ENT [ear-nose-throat] symptoms, or any other symptoms pertaining to any other system--they are coming to the hospital for treatment. So, we need to have a very high index of suspicion.

We cannot say that patients having only a particular set of symptoms, or only those who have a travel history or contact history will be suspected to have COVID-19. Right now, any patient, with any symptom coming to a hospital has to be a suspect until and unless proven otherwise. We have to follow that, because unless we do that, we will be unnecessarily exposing ourselves, and other healthcare workers, and everybody, if we do not suspect them and then do not take adequate protective measures.

We are also finding lots of asymptomatic carriers now--people who are fine, healthy, no symptoms. When they are being tested--by contact tracing--they are coming out to be positive, and they are remaining positive for a considerable period of time--over two weeks, and upto 3-4 weeks even. So, when these asymptomatic carriers are going out and mixing with family members, healthcare workers, and other people in the community, they would be spreading the infection. Maybe they are not developing symptoms because their immune system is handling [the virus] in that way, but it is not necessary that each and every person’s immune system can handle [it] in the same way. The vulnerable group--elderly people, those who have other comorbidities like diabetics, chronic kidney disease patients, cancer patients, very young children, pregnant women--get the infection. If the infection spreads like that, the mortality statistics we have right now are pretty high, and it is alarming in a country like India.

You mentioned that people are coming in with gastrointestinal symptoms. How do you relate that to COVID-19? Or is it that these are people who have some kind of gastrointestinal problem and also have COVID-19?

This is occurring in both ways--people having some GI ailment are getting COVID-19, and the virus is being shed in the stool. The virus goes into the GI tract and it infects the intestinal cells. So, it is both ways: A person who has some previous GI comorbidities is getting the symptoms; or the patient may not be having any GI symptoms, but is getting GI symptoms because of the COVID-19 infection.

We were assuming, to a large extent, that the early signs are going to be respiratory problems, and you use that to do a primary diagnosis. But you are saying that, in this case, a patient who comes may not have a respiratory problem at all, but only have a gastrointestinal problem and COVID-19? That makes it much tougher.

Exactly. That is much tougher. That is why I told you, that each and every patient who comes to the hospital [should be considered] a COVID-19 [suspect] unless proven otherwise. If we take this stance right now, maybe we would be able to diagnose more and more COVID-19 patients. The index of suspicion has to be very high, because we do not know how they will manifest, what symptoms they will come up with. Now, each and every day, we are finding people with newer symptoms coming, which we had not thought of before.

I am sure that you are talking to fellow colleagues and doctors across the country. Are you seeing any trends in Kolkata or West Bengal which are different from other places?

No, we are not finding any separate trends in the manifestation, as such, in what we are finding in Bengal or Kolkata, that is different from what is there in Delhi or Chennai. This is all similar. The only thing where Bengal was lacking, as I had said before, was not enough testing was being done before. So, we were not getting enough cases. That was one of the main issues. If you look at the testing rate in Maharashtra or Kerala, for instance, in Bengal it was much lower than those states. Now, Bengal is coming up, the testing rates have increased and that is a good thing. So, now we are finding more and more cases. But still, it has to go up and there is still a long way to go. We need to do much more tests till we know the exact situation in Bengal in totality.

As an immunologist, what is your sense of how this is likely to progress?

Immunologically speaking, COVID-19 is a very interesting disease. What we are finding mainly in patients who have gone into the severe disease is that the immune response of the body against this virus is totally chaotic. The immune system is confused. The cells are producing all sorts of chemicals and cytokines, and sending them into the blood, and giving all sorts of chaotic signals to various tissues. So ultimately, instead of protecting the body from the virus, the body responds in a very aberrant fashion. We get something like a systemic respiratory inflammatory symptom--we call it a cytokine storm, or cytokine release syndrome. All this leads to much more problems in the body rather than doing good. They do more harm. And these are the reasons why patients become more critical, leading to multi-organ failure, towards death and mortality.

There are telltale signs, some parameters that we can check before, and can prognosticate that a patient will likely go into a severe or critical stage, or that they will most likely come out of it. We have some immunological parameters--immunophenotyping is a very interesting tool, but not many hospitals have access to it. We can do a CD4 count, which is usually done for HIV. A low CD4 count [in HIV patients] is bad, and the patient will likely go into AIDS. Similarly, for COVID-19 also, a low CD4 count is bad, and the patient will most likely go into severe or critical COVID-19--the outcome is not going to be good. Apart from that, there are other measures also, such as cytokine levels--Interleukin-6, Interleukin-2, Interleukin-17. If these cytokines can be measured before, they usually show whether the patients will go into the bad phase. Apart from that, the lymphocyte count is very important--patients with a low lymphocyte count are most likely to not fare well. These are the evidences and parameters that can be checked before, and they can give an idea. Though a majority of the patients will come out of it, there is a particular group of patients who will go into a critical state, into [needing a] ventilator, no matter what we do. If we detect these patients early, we can take steps so that these patients can be prevented [from going into a critical stage], and can take extra care for these patients.

As we emerge from a lockdown in many parts of the country, what should people do? What are you advising your patients?

Firstly, we need to know why we went into lockdown, and then, we will come to know when and how we can come out of the lockdown. We went into lockdown to reduce the virus transmission in the community; if people lock themselves at home, not going out or mixing with others, the human-to-human transmission is reduced. If we can have a lockdown for a considerable period of time--49 days or 21 days or anything depending on the viral replication rate, which we know now--then, viral transmission in the community goes down. And once it goes down, this virus will not be able to affect the majority of the population in a community. In that manner, we prevent the virus attacking the vulnerable people. The next thing is, how and when do we come out of the lockdown. When we have gone into a lockdown, it does not mean the virus goes away from the community. We have only reduced the transmission of the virus.

The lockdown period is utilised mainly for two reasons: One is infrastructure building, we need to have more ICUs and ventilator units, so that more COVID-19 patients who become very sick and need hospital admission can be taken in. And second thing is that, we need to do as much testing as possible so that we are able to understand how the virus is spreading in different parts of the country. It will not be the same; now we know that the virus transmission in various parts of the country is different--even in a city or within a district, it is different. This information helps us in containing only those areas where there is active viral transmission, and allowing the lockdown to ease out in other areas where the transmission rate is very low.

Whenever the government is classifying districts into zones--red, orange and green zones--one needs to know one important parameter: What was the total amount of testing done? If we find that the testing rate was very low in the green zone, our classification may not be right. If the testing rate is quite high and adequate in all the zones, then the zoning is going to be perfect and that will reflect the true picture in the community. And by that way, containing those areas and easing the other areas where transmission is decreasing, we can definitely bring this disease from an epidemic to an endemic. Anyway, it is going to be endemic. Many people say that the herd immunity concept is there--though there are lots of debates on it, I am not going into that. But this is how it should be. Otherwise, we are going to again fall into a trap; once the lockdown gets over, people will come out, the virus will again start spreading and lots of cases--a surge of cases--will be there.

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