ECONOMYNEXT – With up to 500 new COVID-19 cases reported every day, Sri Lanka ought to conduct 40,000 to 50,000 PCR tests a day, well above the current rate of less than 12,000, if it is to successfully contain the ongoing outbreak, a leading epidemiology expert said.
Executive Director and fellow of the Institute for Health Policy (IHP) Dr Ravindra Rannan-Eliya has called for increased testing in order to contain the outbreak without resorting to lockdowns.
“During the past six months, the World Health Organisation (WHO) has suggested various testing levels as being adequate, ranging from 1 test per 1,000 people each week to 30 tests for every positive case detection. These translate into rates of 3–15,000 tests/day in Sri Lanka currently. Our assessment is that these guidelines do not have a strong evidence base, and that these levels of testing are too low to achieve and maintain elimination, which needs to be our goal if we are to avoid lockdowns as desired by our President,” Dr Rannan-Eliya, a public health expert as well as an economist, wrote in a post written for the IHP blog yesterday.
EconomyNext spoke to Dr Rannan-Eliya via email yesterday on his expert views on Sri Lanka’s response to the new wave of COVID-19 that has now surpassed 10,000 cases in a period of just one month.
Excerpts follow, with some light editing for clarity.
EN: Do you think Sri Lanka can afford the economic losses that will occur from not increasing testing?
RR: The money [for increased testing] is available. The initial cost/forex requirement of expanding machine capacity (USD 7-10 million) can be easily financed by the current World Bank COVID project (USD 128 million). In the longer-term, this is not a cost. By keeping transmission at low levels, the additional profits that local business will generate by not having to endure lockdowns and reduced consumer confidence (and labour shortages as EconomyNext reported is occurring in the tea sector), and the additional income taxes and VAT that Treasury will collect will pay for the operating costs more than several fold.
There will, however, be a political cost for the Samagi Jana Balavegaya (SJB) and others. I note that President Trump almost certainly lost re-election because of mismanagement of COVID-19. It will be very bad news for the opposition if the government increases testing as we propose, and can get the economy back to growth as a result.
EN: What is your opinion on the antigen test? Will it help meet our testing requirements and be compatible with Sri Lankan requirements?
RR: The performance of antigen tests varies a lot between manufacturers and also depending on how they are used. Without proper testing, I cannot say how good the particular kit is that the Ministry of Health (MOH) has imported. Overall, they are not as good as PCR testing in detecting new cases, and performance also depends on how they are used. To slow transmission, we need to maximise our ability to detect cases.
Antigen tests will not be as good at doing this. So 1,000 antigen tests will be not as effective as 1,000 PCR tests. So, long term, we need to rely on PCR testing. However, we now have a serious problem because our PCR capacity is limited, so we have no option but to use other inferior methods such as antigen tests to compensate until the MOH installs the increased PCR capacity.
EN: Regarding the current situation in the country, do you think we are still not at the community spreading level? MOH Epidemiology Head Dr Sudath Samaraweera said even though the number of patients increased, the patient count in the Gamapaha district is dropping. What is your take on that?
RR: The Epidemiology Unit is using the term “community spread” as defined by WHO where it refers to whether the origin of cases can be identified. As I have explained before, I do not think that we should rely on the WHO classification, and as a scientist i do not find it helpful for COVID-19.
I would rather not get into this discussion because I think we and the media are pushing the MOH into a corner. They are probably afraid of the political implications of changing WHO categories. Frankly, if the MOH wants to use the term “community spread”, I think they would be smarter to defuse the situation by using the term to classify individual cases as, say, Australia does, and not try to pigeonhole us into a WHO category which may have political implications.
That is, they should in future simply report how many cases are (i) imported, (ii) local cases of known origin, and (iii) community spread cases where the origin is unknown. Then we can get on with focusing on the number of overall local cases and the level of transmission, which is what really matters.
Regarding the Gampaha question, the real issue is that we see no evidence of nationwide transmission slowing. We have been detecting a steady 400-500 new cases/day for some time, and we can also see that PCR testing has been stuck at about 10,000 tests/day. There is a possibility that the real number of new cases is increasing, but we are no longer able to detect this because we cannot increase PCR testing.
EN: How effective is the current strategy of the government? In your opinion, do we need to go for a different strategy?
RR: Some components are very good, but the overall strategy has clearly failed.
The border closure in March, which I should point out was only put in place at the urging of medical experts like myself and the Government Medical Officers Association (GMOA), was a good decision. The very effective quarantine facilities and contact tracing and isolation led by the military and intelligence services have been world class, and we should be grateful. But there has been one consistent and enormous failure in the overall strategy, which will undermine all the other good efforts. That is the failure to build up PCR testing capacity after April as other countries did, and the failure to start routine testing of all patients with respiratory symptoms, coughs, colds or fever. There has been enormous resistance in many parts of the MOH and in my profession, to the idea that high levels of testing were needed for COVID-19 control, and this resistance has cost us dearly.
EN: What is your position on not conducting PCR tests on people who have passed the 14-day quarantine period?
RR: The risk that international arrivals who have not displayed symptoms for 14 days in quarantine are not infectious is low, but the scientific evidence does not exist that allows us to say with 100 percent confidence that the risk is zero. Some countries that have had 14-day quarantine with PCR testing have had outbreaks which they suspect were caused by undetected cases getting through quarantine. So in a situation where the goal is elimination and we have PCR testing capacity, then it is safer to err on the side of caution and test. I note that New Zealand continues to do this. However, we have now run out of PCR testing capacity. Given this we may need to prioritise, accept increased risks for now, and use our limited testing capacity instead for detecting community cases.
EN: Does the new coronavirus lose its ability to infect other people after 10-14 days of infection?
RR: In cases where the person is very sick, infectiousness can last a lot longer than 14 days, and this has been well documented since at least March. But I think you are referring to cases where the person has no symptoms or only mild symptoms, where the risk of infection after 14 days is very low.
However, as I explained, we do not have scientific evidence to say that it is zero. I think some doctors are pointing to a recent US CDC assessment that it is zero. However, if you read the CDC document carefully, their conclusion is based on one Taiwanese study which did not have a large sample, and so was not able to conclusively determine that the risk was zero. The CDC also noted one other Chinese study which suggested that people could remain infectious for much longer.
The way I would interpret this is that the CDC is primarily trying to provide guidance in a country – the USA – where the virus is rampant, infecting hundreds of thousands every day, and where the President’s own Chief of Staff is on record as saying they have given up trying to control the virus. In this context, they only worry about minimising risk and not about getting risk to zero, so they can afford to accept a low level of risk. As a country which until recently had near zero cases, we need to take a harder look at the same evidence. (Colombo/Nov10/2020)