UP economics profs recommend sector-based random sample testing

Metro Manila (CNN Philippines, April 22) — A group of economics professors from the University of the Philippines (UP) has proposed the use of sample-based random testing for COVID-19 from among the different industries or sectors and localities such as barangays to fully understand and monitor the transmission of the deadly virus.

In discussion papers by 12 professors of the UP School of Economics plus one professor from the College of Medicine, they said their suggestion entails a two-level design, which is composed of a random sample of firms, and another of employees within the selected firms identified by the Department of Trade and Industry and the Philippine Statistics Authority. Both agencies will determine both samples.

Meanwhile, local government units will identify firms operating exclusively within their borders, such as neighborhood or city markers, retail stores, and local transportation providers.

The size of the random samples will depend on the firm size, which are 30 or less workers, 31 to 100 workers, or over a hundred workers, and the physical location or nature of workers within a firm.

Some workers will also receive more frequent testing depending on the nature of their jobs.

The professors recommended using the rapid antibody-based test, which costs ₱1,930 on the workers that will be included in the sampling. Should anyone test positive, the RT-PCR testing protocol will then be executed on the entire shift of workers exposed to the infected individual.

For this protocol, they suggested the pooled approach, which will test blood samples or swabs from workers by group or batch instead of just one individual being tested.

Meanwhile, if any worker tests positive for the disease using the RT-PCR test, the group said all workers must be brought to a quarantine facility or in a hospital if they're symptomatic, the workplace must be disinfected, and contact tracing must be done in the community where the infected worker lives.

The group said this form of testing is a "feasible and economical way" to keep infections under surveillance, adding it could "cost a fraction of mass testing yet still provide statistically reliable information."

This method also allows for the monitoring of 'herd' or community immunity, which means a group of people is protected from the disease if enough people are resistant to it, leading to infection rates dropping and the disease eventually dwindling, the professors said.

Meanwhile, the professors found the current approach by the government, which prioritizes only those with symptoms, is not capable of giving an estimate of how many are actually infected, especially asymptomatic people.

It is also unable to reflect disease transmission rates and other indicators required to design policy, such as when and how to lift the enhanced community quarantine and deployment of health resources across localities, the group explained.

"As it is, little is known about whether, when, and where surges of new cases may happen," it added.

The group also said there is an urgent need to expand the Department of Health's capacity in granting accreditation to private and LGU laboratories, in order to allow for more RT-PCR testing, whose current capacity will be overrun even with pooled testing.

The group is composed of UP School of Economics Dean Orville Jose C. Solon and faculty members Toby C. Monsod , Maria Socorro Gochoco-Bautista, Emmanuel S. de Dios, Joseph J. Capuno, Renato E. Reside Jr., Ma. Joy V Abrenica, Agustin L. Arcenas, Ma. Christina Epetia, Laarni C. Escresa, Karl Jandoc and Cielo Magno. UP College of Medicine faculty member Carlo Irwin A. Panelo is also part of the group.

The full paper may be read here.