DoH cautions against Covid pool testing

THE Department of Health (DoH) said it was readying guidelines on the use of testing methods for the coronavirus disease 2019 (Covid-19) as it warned against doing pool testing in high-risk virus areas.

Several local government officials have proposed pool testing to effectively test more people in their communities.

Health Undersecretary Maria Rosario Vergeire said pool testing was only effective in areas where the prevalence of the virus was low.

“If you are in a high- prevalence area, or an area with so many cases, it won’t be efficient... as it defeats the purpose of pooled testing” Vergeire, who is also DoH spokesman, told a media briefing on Friday.

Vergeire said if pool testing was used in an area with a high number of cases, many positive cases that would show up in the pool would require testing of the members of that particular pool.

She said the DoH was considering pooled testing in areas with a low Covid- 19 count for selected sectors such as vendors and cashiers.

Vergeire said the department was checking areas where pool testing could be done.

The Research Institute for Tropical Medicine and the Philippine Society of Pathologists are trying to evaluate how many pools would be needed, if five, 10 or 20 samples are in one test,” Vergeire said.

Presidential Adviser for Entrepreneurship Jose Maria “Joey” Concepcion 3rd on Friday agreed with Vergeire that pool testing would only be efficient in low-prevalence areas.

“We agree. It’s not cost- effective when the prevalence [is high] and you might as well go one on one,” Concepcion told The Manila Times.

But Concepcion, who is also the founder of Go Negosyo, believes that by reducing the number of pools, pool testing can still work in high-prevalence areas.

In high-prevalence areas, pools of five or fewer can be used, and up to 20 in low-prevalence areas, he said.

“[When] there are high cases of infection, you cannot go for a high number of pools. You cannot use 10, use 20 but definitely you can use 5,” he said.

Using the pool testing method, swab samples of multiple individuals will be lumped into a single reverse transcription polymerase chain reaction (RT-PCR) test.

If a positive result comes back, further individual assessments will be made to determine which specimen is infected. If the swab tests come back negative, then there is no need for individual testing.

On Wednesday, Concepcion said pool testing would be piloted in Makati City next week with public utility drivers and public market vendors as the initial target sectors.

Makati Mayor Mar- Len Abigail Binay expressed hope that the results of the study on pool testing would have a “big impact” on mass testing protocols and could lead to “more efficient” handling of coronavirus cases all over the country.

Vergeire said the DoH was also finalizing the omnibus guidelines on the use of testing kits, which aims to put in a single document all methodologies for Covid-19 testing.

She said the guidelines on rapid testing would inform the public, as well as health facilities, what tests to be used during various stages of virus infection.

The DoH also announced that it has opened its 100th Covid-19 RT-PCR testing laboratory at the Chong Hua Hospital in Cebu City.