Ex-DOH chief: Actual number of virus cases could reach 75,000 in 2 weeks

MANILA, Philippines – What is the actual number of coronavirus cases in the Philippines?

As of March 28, there are 1,075 recorded cases, 68 deaths, and 35 recoveries in the country. These are the numbers announced by the Department of Health (DOH), which are based on the confirmed cases.

These figures, however, do not include those that are left undetected. These figures are also “the picture 7 to 10 days ago,” according to former health secretary Manuel Dayrit, because that’s how long test results come out on average.

But Dayrit, the DOH chief who led the charge against SARS from 2002-2003, also said that "we can actually learn" from the data we have, despite the limitations.

In the Rappler Talk hosted by Maria Ressa on March 27, Dayrit and Erika Legara, Aboitiz chair in Data Science at the Asian Institute of Management (AIM), discussed the importance of data and the actions that needed to be taken to effectively beat the coronavirus crisis. (WATCH: Data and facts – what the PH can do to deal with coronavirus)

Importance of data in determining actual number of cases

In order to understand the pandemic, Dayrit said one of the important figures to look at is the reproductive rate, or the number of cases that one positive case might infect.

Dayrit said members of the Inter-agency Task Force (IATF) for the Management of Emerging Infectious Diseases pegged the country's reproductive rate at 4, based on data they got from China. This means they estimate a COVID-19 patient to have infected 4 other people.

Legara and her colleague Christopher Monterola, also an Aboitiz chair at AIM, has earlier projected that coronavirus cases in the country could reach 26,000 by end-March if random spread is not contained. This was projected using early March figures from the DOH, before the Luzon lockdown was imposed.

“If we’re assuming that we’re now at 16,000 to 20,000 (infections) today, and if you’re assuming doubling times of every 5 days… we’re going to reach 75,000 in 15 days. And that’s when our lockdown period ends,” Dayrit said.

The former health chief, however, reminded that these mathematical projections still rely on several assumptions such as reproductive rates and doubling times of the cases. "This is the way you would try to map the progress of your epidemic," he said.

The Luzon-wide lockdown is expected to be lifted on April 12, but both Dayrit and Legara said the cases are likely to surge by that time.

“One of the things that’s really bothering me at the moment is that when it was announced on the 15th that we’re going to have a quarantine and they’re going to lift this on the 12th of April, my question was - what’s the basis of that? Would we be ready by then?” Legara said.

Given that the data released by DOH is about 7 to 10 days late, said Dayrit, the “number crunchers” will have to figure out what were the cases that were occurring before and after the lockdown period. Then, the government will have to figure out what to do at the end of the lockdown period, he added.

“Given the backlog in our testing, every day we announce these new cases as if they’re growing and growing, but that’s actually also a result of the backlog of tests. So we know that the virus is already out there in the provinces. And therefore, that’s one message that has to go out. That the virus is there, and they have to do the proper containment so that it doesn’t spread,” Dayrit explained.

Legara added: “Without data, without data-driven decision-making processes, things could get even worse for us. So, yes we should flatten the curve, but for how long? They say 1-2 weeks should be enough, but we need to see that working. And the only way for us to really see that working is if we have enough data to give a more honest assessment, to have a baseline that such measures are truly working.”

Test, test, test

Testing plays an essential role in making projections, because the more tests conducted, the more accurate the data will be. However, laid against population data, numbers as of March 20, 2020 showed that the Philippines has been conducting only around 12 tests for every million people. (READ: IN CHARTS: PH lags behind other countries in COVID-19 testing)

For about 2 months since late January, the Research Institute for Tropical Medicine (RITM) was the lone facility that handled tests for COVID-19. But as of today, there are now 5 accredited testing centers in the country. The additional testing centers should now be able clear the backlog that is at the level of about 1,000 samples, Dayrit said.

“So I would say, clear the backlog so that the cases that we’re reporting – we know are already at least 7 days late – would provide us an even more accurate picture, even if late. Make the projections as a result of that, and then from there, work out the plans,” Dayrit said.

The next steps

In order to effectively manage the cases and eventually slow down the rate of infection, Dayrit and Legara suggested 4 things: test more people, monitor data, create more hospitals dedicated to COVID-19, and provide adequate supplies for health workers.

“You see, when you do the tests, you actually try to cover as many of the population, as many of the general population who are out there who think they may have encountered somebody who is infected. And that, in a sense, gives you what epidemiologists would call some ‘prevalence information’ of what is the level of infection in your population,” Legara explained.

Dayrit hopes the backlog of tests would be cleared within the next two weeks, so that more people would be tested. – Rappler.com

Pauline Macaraeg

Pauline Macaraeg is part of the Rappler Research Team’s fact-checking unit. Aside from debunking dubious claims, she also enjoys crunching data and writing stories about the economy, environment, and media democracy.