Is a new covid-19 strain responsible for the Minuwangoda outbreak?

Dr. Pradeep Kariyawasam

Former Chief Medical Officer of Health, Colombo Municipal Council.

The total number of Covid-19 patients in the first seven months was around 3,500 but during the past two weeks another 1,600 were found as the result of the Minuwangoda outbreak. I call it the Minuwangoda outbreak as obviously some people have had the virus infection without being reported before it entered the Brandix factory. It has spread its way into farther parts of the country such as Jaffna and Monaragala and the numbers are rising. Gradually more and more districts are getting involved but the numbers are low so far.

We cannot fight this pandemic alone as it has enveloped the whole world and we must study the global spread and the virus strains, especially if we are getting those Sri Lankans stranded abroad back to this country. This is a new disease caused by a new virus of which we have only a little understanding. Although the PCR tests could report a positive result only 50% of the persons show symptoms. It is not known for sure whether a person who has the germ but not showing any symptoms of the disease could infect another person. The virus can survive on surfaces up to 28 days according to new reports. So, this is not only an air-borne disease and the importance of handwashing and sanitizing is highlighted. The incubation period is 5-14 days. The quarantine period is 14 days. We had controlled the disease to a great extent but the arrival of Lankans from abroad changed the situation. Supposing someone gets infected in the plane from another passenger and show symptoms on the 14th day of getting infected and use the same transport back from quarantine centres, they will definitely pass the virus to others. This was noticed and some suggested that the quarantine period should be increased to 21 days thinking that the incubation period was longer, which was not reported by any other country, and later it was decided to quarantine them for another 14 days in their own homes. Even if one infected person gets through the net that is enough for a major outbreak somewhere else which I believe is the present case. That combined with complacency shown by the people who stopped wearing masks, not adhering to social distancing and forgetting about hand-washing obviously created the present situation. In both private and govt sector offices the managers hardly wore masks that set a bad example to their sub-ordinates.

Even with many ups and downs the country managed the disease very well where the forces combined with the health personnel to control the spread. Many lessons were learnt while they were on the job. While treatment procedures adopted were outstanding, the PCR testing was hardly adequate. The reasons are not known but now I believe that it is raised up to 6000 tests a day. Considering that the false negative rate of the test is between 2-29% according the British Medical Journal, and 2-37% as reported by Harvard Medical School, it is necessary to test the same person twice or thrice. The false positive rate is only 4% and therefore if a person has a positive PCR test then it is better to consider that person a Covi-19 patient. This shows that we may be not covering all the persons who are really infected. We went on carrying out tests on so-called high-risk groups in urban areas which was non-productive and a sheer waste of time and money considering that the private hospitals charge between Rs. 6000 to 9000 per test. Random testing also is like trying a find a needle in a haystack which is a waste of resources. While tracing the contacts it is important also to do reverse contact tracing with an open mind not to try to link only to Minuwangoda. This disease doesn’t care whether one is rich or poor. Therefore, it is better to consider testing those who have the symptoms only i.e. with a fever, sore-throat, cough and cold, difficulty in breathing or any one of them. If such a practice is adopted, I am sure the number of positives could be much higher and we may not miss many covid-19 patients.

All is not lost. Although the flu season is on in the Northern Hemisphere, I am sure we could contain the spread of this disease again. Moreover, studies suggest that with covid-19 on the rampage the flu rates are getting lower and that getting flu will temporarily prevent covid-19 infection. Information coming out of the Duke University, USA states that countries with lower covid-19 rates are the countries with high dengue epidemic rates in the recent past which means that there is a possibility of cross-immunity between dengue and covid-19. Also, it states that if one has got dengue fever then there is a chance of a false positive result if the antibody test is done. Is this why we have had lower covid-19 rates? This year we had very low dengue fever incidence so we might not have that advantage too.

What is needed is common sense to prevent further spread of the disease. All hospitals and General Practitioners should try and send those who have the symptoms for PCR testing. Considering that the virus changes with time even slightly, the researchers here must warn if there is a change in the virus strain so that we can be prepared for it. It is known that the virus found in the USA, Canada, Europe is a more transmissible mutant strain, and when one looks at the rate of infections during the past few days maybe it started the present outbreak here too. We know that this is also the dominant strain in India although different lineages are found regionally. The Chief Epidemiologist says that the virus load found in individuals is higher now. The researchers in this country should work hand in glove with those conducting control programmes by monitoring the situation and advising the Ministry of Health. Unfortunately, my experience is not that. Years ago, the professor of Microbiology from Sri Jayewardenepura University came to my office and told me that the dengue virus has changed to Den-3 and an epidemic was imminent but no one was listening to her hence she had decided to come to me. What the officials should do is to support the researchers also by giving data. Even the GMOA is not given data. It is good if strict quarantine regulations are implemented to the letter now. The media should not overdo their act by showing individuals who have unfortunately got the disease which will discourage others from coming out to seek treatment or get tested.