Testing and granular lockdown

What we know and how much we know about COVID-19 changes every day. Our containment strategies have to evolve in tandem with the virus, which is why we tried rapid antibody testing and RT-PCR testing. Now, we are piloting pooled PCR testing with the city of Makati, which I believe will be a game-changer. In the future, we can also explore antigen testing, which works by checking the presence of a viral antigen that becomes present in current viral infections.

Innovations in testing strategies are necessary to create the visibility we need to fight the virus. Since the start, I have advocated for mass testing as the only way we can move to trace, isolate, and treat patients. At the beginning of this pandemic, rapid antibody test kits were the only available weapon at that time to map out the spread of infection and scale up our healthcare facilities. We had to make the most of what we had at that time, but we remained open to alternative testing strategies. Now that we have gathered sufficient resources and enough information about the virus, we will implement pooled testing.

The results of a major research study by the Philippine Society of Pathologists Inc., Research Institute of Tropical Medicine, and Philippine Children’s Medical Center (PCMC) recommended pooling five swab samples in one RT-PCR test kit as the optimal way to maintain 98 percent accuracy without too much dilution. The recommended pools of five will be able to offer 70 percent savings and speed up turnaround time by 1.08 times, although the dilution brings the sensitivity rate to 83 percent.

In terms of costing, pools of five will range from P400 to P750 per person in the pilot implementation. This represents a significant decrease in cost from a single PCR test, which can cost from P4,000 to P8,000.

Pooled PCR testing is not a silver bullet, but it can support surveillance efforts, especially in screening asymptomatic individuals. The PSPI recommends pooled testing for low prevalence communities; mass testing in hot zone communities; surveillance of healthcare workers and frontline government workers; workplace testing to include factory workers, market vendors, call centers, transportation workers; border testing at airports and seaports for inbound foreign travelers and returning residents; overseas deployment of OFWs, returning OFWs; and locally stranded individuals (LSI).

I believe pooled testing is another weapon we can use against the virus, especially since speed and affordability are very important in our pandemic response. Cure or no cure, we have to co-exist with the virus. How do we co-exist? We have to create greater visibility that only mass testing can provide.

I am grateful to the city of Makati for joining us in this pioneering project which may encourage other cities to follow. As part of the pilot, we will test 10,000 individuals, focusing on public market vendors, tricycle, jeepney, and pedicab drivers, as well as a community near Makati Coliseum. “Pooled testing will be helpful not just to our constituents, but also to our business community who are unable to afford the P3,500 PCR test. Hopefully, this will encourage our companies to (resume operations, and) our employees will be assured that they are not spreading the virus as well. Hopefully, eto na po ang sagot na hinihintay nating lahat so we can all move forward and live with COVID,” Mayor Abby Binay said during the launch.

On its own, mass testing is not enough. We have to move towards more granular lockdowns whenever infections surge, doing away with broad-based quarantines that span Luzon or Metro Manila. The approach should be data-driven and should provide fast results so we can move to isolating and tracing within a maximum of two days. In locking down, we should focus on clusters - even at the street level - with high infection rates, so we can direct our limited resources accordingly. Shifting towards barangay-level lockdowns empowers local leaders to protect their people and communities.

This approach gives more power to the LGUs in enforcing the lockdowns in their respective areas of control. I believe our mayors are the most capable people in determining where to lockdown. In the meantime, economic activity can continue in areas that are not under lockdown, and businesses may resume operations. Once infection levels stabilize, we can open the economy even further and save as many jobs and livelihoods as we can, especially MSMEs who have been extremely challenged in this pandemic.

In helping mitigate the spread of the disease, the UP Pandemic Response Team has also proposed using a simplified computation based on a time-varying reproduction number, or R(t), which measures “how fast the virus is growing” and “the average number of people who become infected by an infectious person.” The US uses this approach in its decision-making, and its data is shared in real-time on rt.live. We can adopt the same approach here. Though not an exact science, it is useful and can be used by the IATF and LGUs until a cure or vaccine is found.

Balancing health and the economy is a challenging task, but we have to do it. It’s not a matter of choosing between these two options, but striving for an optimal balance of the three – saving lives, jobs, and livelihoods. Massive targeted testing – using all testing strategies at our disposal – and a strategic, granular approach to lockdowns is the best way forward.