Medical Faculty don forewarns imminent tipping point

SL COVID-19 epidemiological trend bleak

By Sajitha Prematunge

From 200 to 300 positive cases, in mid-April, to over 3,000, in mid-May, the number of COVID-19 positive cases seems to be increasing exponentially, with the number of fatalities having surpassed the 1,000 mark on Tuesday (18). But epidemiology and public health experts warn that the numbers are just the tip of the iceberg.

Colombo University Medical Faculty, Community Medicine Department Head, Prof Manuj Weerasinghe says that the actual ground situation is far bleaker than the numbers would have one believe. An expert in epidemiology and public health, Weerasinghe points out that three simple facts ought to snap policymakers, and the general public, out of their complacency – a result of the false sense of security afforded by the number of positive cases and the relatively few deaths, compared to other worse affected countries. “One, the actual ground situation could be much worse. Two, detections are made through testing and hospital admissions, and there are many more that go unrecorded, and three, lapses in the vaccination process.”

Prof. Weerasinghe further explains that the fewer numbers could result in ill-informed decisions on the part of policymakers. “Everyone is hung up on the number of positive cases, specifically because there was a sharp rise from 150 to 300 to over 2,500 just after April 14. But, in fact, the ground situation could be much worse.” Based on the preliminary predictive modelling done by WHO HQ in the last week of April, and if the current trend continues with no interventions, Sri Lanka would most likely be reporting 10,000 cases daily within the next three weeks. But, according to Weerasinghe, this exponential growth in infections will go unnoticed as this goes beyond our testing capacity. 

According to Weerasinghe the current numbers depend heavily on the number of PCR tests conducted. He explains that Sri Lanka’s capacity for PCR testing is between 15,000 and 23,000. “30,000 per day is a stretch that would strain our laboratory resources.” The number of positive cases is only a sample of the population and if testing was to be increased so would the positive numbers. “They are drawn from those in quarantine or are hospitalized. Consequently, it’s just a sample of the population.” Weerasinghe pointed out that the numbers will plateau between 2,700 and 3,000s. “But this is only due to the restricted capacity of testing. He argues that even while coordinating the outsourcing of 25 to 30 percent of PCR testing to the private sector, by the government, Sri Lanka is still not conducting enough tests that would amount to a healthy representation of the total population.

“It’s no reason to be complacent. The positive cases number always reflects the number of tests done.” In fact, Weerasinghe postulates that the daily actual infected number could be two or three-fold the numbers recorded. “They either don’t know that they are infected yet or are asymptomatic.” The catch, according to Weerasinghe, is that resources required such as hospital capacity, ICU beds and oxygen reserves are calculated based on these numbers that are quite misleading.

According to Prof. Weerasinghe, of the 25 to 30 percent that are symptomatic, 17 to 20 percent may require oxygen. He further explained that those who do not experience any discomfort are unlikely to seek medical assistance. For example, certain people may suffer from hypoxia, deficiency in the amount of oxygen reaching the tissues, without experiencing any physical discomfort. “But their condition may progress quickly within three to four days,” says Weerasinghe. The snag is that there is a higher number of those experiencing delayed onset of symptoms, are only mildly symptomatic or are altogether asymptomatic, than the numbers would have one believe. “These people go to their GP [General Practitioner] for breathing difficulties and often go untested. It’s imperative that we make a policy decision to manage such patients as potential COVID-19 infected individuals,” emphasises Weerasinghe. He explains that this is vital for taking public health measures. “The problem is that policymakers cannot appreciate this fact.” Weerasinghe maintained that COVID management has to be proactive rather than reactive. “Our current approach is in reaction to reported cases.”

The increase of deaths also signals a vicious cycle, according to Weerasinghe. Those who experience delayed onset of symptoms are hospitalised late or go undiagnosed until their condition progresses so  much so that they require advanced care. “Invariably a certain percentage of these patients will die. We have to acknowledge this reality and forecast at least three weeks in advance instead of working based on past data,” reiterated Weerasinghe. He explains that it would take up to two weeks to observe results of any kind of intervention, such as deployment of health staff, establishment of hospitals or improvements to the supply chain. “We shouldn’t get too caught up in stats like ICU bed numbers, and instead focus on the ground situation, the number that goes untested,” emphasizes Weerasinghe.

Prof. Weerasinghe impressed the importance of enforcing immediate measures to stop transmission. In fact, according to him, the call for restriction of mobility is three weeks late. The call  for such restrictions by April 20, by medical experts fell on deaf ears. “Since this is a proactive game, we must have at least two weeks of stringent mobility restrictions, during which only key economic activities should be allowed to continue. With the haphazard restrictions currently in force, what we have now is a protracted pandemic, which ironically reflects unfavourably on the economy. It’s actually worse than a short period of strict restrictions.”

He also impressed on the significance of not lifting all restrictions at once. “Then all we’ve done so far will be in vain. Only a few restrictions must be lifted at a time. Gradual reopening of schools, but with pubs remaining closed and the ban on public gatherings still in force, for example.”

Weerasinghe’s third point of import, vaccination, is compounded by the shortage of the Covishield vaccine. He informed that, although the National Vaccination Deployment Strategy, even before such vaccines received approval, strongly recommended that the second dose should be reserved for those who received the first dose of any such vaccine, and priority groups such as comorbid and those over 60 years were specified, these recommendations were blatantly disregarded by policymakers. Weerasinghe assumes that, during diplomatic discussions, the future availability of the vaccine was perhaps assured, prompting the government to use up all the existing doses. As a result the second dose of the Covishield vaccine is almost three months late. “We made a mistake in the decision-making process, let’s not repeat it, because under such circumstances the demand for any vaccine far outweighs the supply.”

While emphasising the importance of the vaccination drive, Weerasinghe points out that the vaccine currently being rolled out, Sinopharm, will have little or no impact on the current epidemiological trend. “Vaccination is a medium to long term strategy. Which means that it does not show immediate results. It’s just one preventive strategy.” He reiterates that, in the meantime, vaccination centres must be prevented from turning into COVID-19 superspreaders and in this endeavour, public health measures and Personal Protective Equipment must go hand in hand. When resources are shared among groups some are bound to suffer, says Weerasinghe. And non-COVID patients often have to bear the brunt of the tug-o-war. “For example, dental health staff are at high risk of infection. Therefore some procedures may have to be put on hold. This is not the ideal situation, but it may be inevitable. “

We are now at Alert Level 3, which requires closure of education institutions, reduction in numbers of workers, ban of public gatherings and the curtailing of many other services and facilities that we have taken for granted. “So there is restriction of mobility to some extent even now. All these measures have a deep impact on transmission dynamics and the rate of increase in infections will reduce. However, Alert Level 4 means widespread pandemic beyond control,” warns Prof. Weerasinghe. Let’s hope it doesn’t get there.