Testing campaign in NCR, nearby areas show only 6% positive for COVID-19 antibodies — Project ARK

Kristine Sabillo, ABS-CBN News

Posted at Jun 29 2020 06:36 PM

MANILA — A private group conducting a mass testing campaign said on Monday that the government’s COVID-19 response seems to be working since only a small percentage of residents in Metro Manila and nearby areas tested positive for antibodies.

“Out of the LGUs, 13 have given their results. Mga 42,970 out of the 121,000 (test kits donated),” Dr. Minguita Padilla of Project ARK said during a Palace briefing. 

“A lot of these are lockdown work or measures like wearing of masks, physical distancing. Because of all these LGUs we have done so far in Metro Manila and even outside, 91% to 92% are negative.”

She said only a “very small percentage is positive” at around 6%, which she said was similar to the percentage of the Department of Health for polymerase chain reaction (PCR) tests. 

Padilla did not say what the status is of the remaining percentage although those might be inconclusive tests.

Unlike PCR testing, which is the gold standard of the DOH, antibody testing only measures a person’s immune system response to the virus.

Many local doctors criticized the use of antibody testing because it is said to be prone to inaccurate results.

While the DOH only recognized PCR tests in confirming COVID-19 cases, it allows the use of antibody tests for initial screening. However, those who test positive for antibodies still need to undergo a confirmatory PCR test.

Project ARK, which helps companies run antibody tests, said it has helped order more than 1 million rapid antibody test kits for 427 companies. A large portion of this is meant to be used by the companies and 121,000 were donated to LGUs. While more than 42,000 have already been used by the LGUs, only around 33,000 tests have so far been run by the companies for their own employees.

Padilla said only Manila and Quezon City were “outliers” in the test results, meaning they have a higher percentage of positive individuals.

With most of the 42,970 residents from LGUs testing negative, she said “it’s a good sign that whatever we did worked.”

Padilla also said that the results, which show a similar percentage of results to the DOH’s PCR testing proves that their “protocol is sound.”

She said that to help those who test positive using antibody test kits, they have also donated automated PCR machines to 11 hospitals.

She said these hospitals will only charge P2000 for PCR testing for asymptomatic patients and others who are not covered by the government’s free testing protocol.

Padilla said they are now working on pooled testing, which would make PCR testing more time and cost-efficient.

Pooled sampling refers to combining the samples of several individuals to save up on the use of test kits. The samples are tested individually only when the result from the pooled sample is positive. 

She explained that Israel is doing this by pooling samples of 64 individuals per batch.

“This was how Wuhan was able to test 13 million in 1 week,” she said.

She said it might help the Philippines, which only has a small percentage of individuals testing positive for COVID-19.

The Philippines has a positivity rate of 7% as of June 27. Although it is higher for NCR at 9% and Region 7 at 33%.