Covid-19: Let us hold our nerve
Posted on April 5th, 2020

By Dr Lal Jayasinghe Consultant in Communicable Disease Control UK (retired) (member Public Health Writers Collective) Courtesy The Island

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So far, we have done very well. Let us not forget this. We were very fortunate that the govt. listened to the right people and took their advice on how to control this epidemic namely the Epidemiology Unit of the Health Department. We are also fortunate in other ways as well. We are an island which means the virus can enter Sri Lanka (legally) only via airports.  We are also fortunate in having a good public health network. We are also a small country. Small is certainly beautiful when it comes to controlling an epidemic. So, let us use these advantages to the maximum, which we have done so far.

What we have to do in the situation of an epidemic is well understood by practitioners of that discipline in medicine specially trained for the purpose i.e epidemiologists. As I stated above, the govt. listened to them. In simple terms what needs to be done is to keep patients apart from healthy people. This is nothing new and has been understood for centuries. In order to do so we need to identify the patients. As we knew that apart from the Chinese lady who became ill with Covid-19, there was no Covid-19 in Sri Lanka. Basically, there was not a single corona virus in Sri Lanka.  So, it had to come via the airport.  Therefore, we decided to quarantine people coming into the country and successfully identified patients who we could then keep apart from others. With hindsight the mistake we made was initially to limit returnees from China, South Korea and Iran only for quarantine. We are paying heavily for that initial mistake because cases started appearing in returnees from other countries as well such as India and Pakistan etc.

In situations where we identified patients who have potentially infected others by the time we found them, we quarantined the contacts. Once again, very wisely we did not put all our eggs in one basket by only trying to catch imported cases as our one and only strategy. By declaring a curfew, closing schools etc., we made sure that if cases started to appear in the community due to leaks, there will not be uncontrolled spread.

All these strategies worked very well until we find people who came into the country from abroad and didn’t tell the authorities and therefore escaped quarantine and became ill and infected others. We will continue to keep discovering such patients and contacts. However, we haven’t panicked. And now is not the time to do so. Some people keep telling us that there are hundreds of cases out there in the community. However, this is either speculation or based on modeling. If there are such numbers, they must be asymptomatic because they don’t seem to seek treatment. In that case they are much less infectious. After all Corona is also a virus and not an alien such as you find in Hollywood films. Viruses and diseases caused by them behave in a predictable manner, even if some viruses are more infectious than others. The spread of the disease is easier from a more severe case. Also, the more severe the disease the more likely the patient will have symptoms. What this means is that if there are cases out there who are ill with Covid-19 but going about because they are not ill enough to seek treatment, then they are less likely to spread the disease. Therefore, if at this time we concentrate on identifying Covid-19 patients who seek treatment because they are ill, we will catch the more important cases.

Another feature of spread of a disease caused by viruses, especially respiratory viruses is that the closer the contact with a patient, the more likely we are to catch it. Clearly, this is common sense and not rocket science. Therefore, having made sure that we quarantine arrivals from abroad, if we test patients who show symptoms of Covid-19 in the rest of the community, we will catch most if not all Covid-19 patients in the community. As far as I am aware, there has not been any cases discovered so far, who have neither come from outside Sri Lanka, associated with a person who has come from outside or is a contact of a known patient.

The authorities have also taken measures to limit the contact of the general population with any unknown patients by closing schools Universities etc. and declaring a curfew. So, let us hold our nerve and have confidence in the measures taken by the govt.

Now I come to a possible source of danger. It is observed that the media, as it is their right, keep reporting, not false information, but different opinions on how to control the epidemic. One opinion is based on modelling.  Modelling is good for academics to talk about but very dangerous to be the basis of policy. This was proved to be true in the case of the United Kingdom. At the initial stage of the outbreak in UK, the authorities rather foolishly decided to do nothing or nearly nothing and more or less to let nature take its course and for people to develop immunity or herd immunity and for the disease to peter out by itself. All this was based on modeling. Very soon saner counsel prevailed and now the policy has changed and more traditional measures like shutting down and social distancing are in place.

Mathematical models are based on reported cases from all countries. Countries have different social structures and behaviors. Therefore, it would be foolish to depend on a model to predict how the virus will spread or otherwise in a particular country.

This is what a paper from a leading American University says:

The forecasting models and data strongly suggest that the number of coronavirus cases grows exponentially in countries that do not mandate quarantines, restrictions on travel and public gatherings, and closing of schools, universities, and workplaces (Social Distancing)”

We cannot by any stretch of imagination say that our cases have grown exponentially.  This may be because we practice: quarantines, restrictions on travel and public gatherings, and closing of schools, universities, and workplaces (Social Distancing)”

 While most countries were suddenly hit by an “epidemic” Sri Lanka was hit by a “cluster” of cases. They were not a cluster in the usual (geographical) sense, but all cases were in a particular group of people with a common feature, namely foreigners or people with foreign associations. Because of this most of our cases were in some respects “expected”. Therefore, we are not surprised at the numbers. So, let us not panic.

A more recent argument is that we should increase testing. This advice too should be nipped in the bud. At present the only reliable test is PCR. This test is expensive and uses reagents and equipment in short supply. It is not a sort of yes or no” test in lay terms and we are told that three experts in the field check the results before declaring the results and is, I understand, carried out only in designated labs. Very wisely, private hospitals are permitted to carry out the test under very strict conditions.

For the uninitiated, lay or medical, it might seem a good idea to test as many people as possible in order to identify new patients and keep them safe. But it is not as simple as that. ALL tests have what is called false positive and false negative results. That is one of the reasons that three experts no less, have to decide whether a result is a true positive or a true negative depending on other factors as well such as the history of exposure, symptoms, other tests etc. What are the implications of false positive and false negative results?  Without going into detail, a false positive will create unnecessary panic and wasted resources (not to mention the possibility of being cared among truly positive patients and therefore actually catching the disease!) while a false negative will give rise to a much more dangerous situation. A false negative result will declare that an infected person is negative and safe to mix with other people without restrictions leading to a disaster by infecting a large number of people. At the present time, a PCR is the most reliable test available. In other words, the false positive and false negative percentages are small if carried out by qualified and experienced personnel The PCR test is very expensive with the equipment and reagents in short supply. So, very prudently the authorities are using the test only on patients who are suspected to be corona positive on other grounds. And this policy in my opinion should continue at this stage of the campaign.

 I have heard people speak of new tests for corona infection that are supposed be 30% successful. Perhaps they mean antibody tests to decide whether a person has had the disease or not in the past. This test is now being introduced in UK tin order to identify health workers who can “safely” go to work with Covid 19 cases because they are unlikely to catch the disease a second time.  In any case what do we in Sri Lanka hope to achieve by widespread testing? If we find someone is negative, that person can acquire the disease in the very next moment after the test. Also, if positive what do we do then? Do we quarantine them? Do we quarantine the contacts? Those who are positive, although in theory they can give the disease to others they are less likely to do so if they are not showing symptoms. What this means is that it is much more efficient if, at present, with our limited resources, we confine our testing to symptomatic patients. In other countries like UK there is another reason for testing. People who have respiratory symptoms or family members with respiratory symptoms have self quarantined themselves. This has created a shortage of workers specially health workers. If more tests are performed it will be possible to release those proving negative to go back to work.

There is one other aspect that needs setting right in my opinion. At the moment, a variety of people speak on the television on the current situation. This can lead to confusion. Without a single source of official and correct information people tend to think that facts are being hidden and tend to believe in conspiracy theories which are plenty. My suggestion is that there should be an official announcement from one and the same official, either once or twice daily at a particular time. If a need arises for some reason to make a special announcement that too can be done as breaking news but from the same source or individual as the routine announcement. If this one official spokesperson is a medical person, he/she can enlighten the public about the government policy and strategy that is being currently followed and give reasons for not accepting various suggestions by numerous people, mostly doctors and politicians as for example not practicing widespread testing.

It would be churlish on my part if I didn’t mention the invaluable role that the armed forces and police play in keeping the country safe from Corona. In the usual situation of an outbreak of infectious disease or an epidemic, the job of tracing contacts is left to the Public Health Inspector. Without downplaying the key roles they play in such normal situations or the important part they play now with the present epidemic, the PHIs couldn’t have traced the large numbers of contacts now traced by the “buddhiya ansaya”. The PHIs neither have the personnel, training or authority that the forces have.

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