The private sector-led Project ARK (Antibody Rapid Test Kit) is expected to expand its pilot implementation of the pooled reverse transcription-polymerase chain reaction (RT-PCR) testing, involving 10,000 people, as it assured the public that it is in "constant communication” with the Department of Health (DoH) as far as the possible cascading of pooled testing technique to public hospitals and accredited laboratories is concerned.
Iloilo Rep. and ARK-PCR Private Sector Chief Implementer Janette Garin said that the Philippine Society of Pathologists Inc. (PSP) and the Philippine Children’s Medical Center (PCMC) will officially turn over the preliminary results of their research study on pooled testing to the DoH.
"As they turned over the results, a meeting will be conducted by the DoH and its officials who will now determine or approve the pilot implementing sites that we have recommended. The pilot implementation sites are all government hospitals,” she said during the virtual announcement of the Go Negosyo’s pooled testing research results.
In Luzon, the proposed pilot testing implementation sites are Jose B. Lingad Memorial Regional Hospital, Dr. Jose N. Rodriguez Memorial Hospital, National Kidney and Transplant Institute, Lung Center of the Philippines, University of Cebu Medical Center (UNMed), Vicente Sotto Memorial Medical Center (VSMMC), Wester Visayas Medical Center (WVMC), and Eastern VIsayas Regional Medical Center (EVRMC).
Garin said the identified hospitals, using their own laboratories and using bigger population of 10,000 people, will “replicate” the pooled testing study.
“After doing that, they will all compare the results, discuss it with PCMC and RITM (Research Institute of Tropical Medicine), and come up with a detailed step by step protocol on how pooled testing will be conducted,” she said.
“The DoH will now issue the necessary guidelines for pooled testing under the leadership of the Research Institute of Tropical Medicine because they are our national reference laboratory. The Philippine Society of Pathologists will be there as mentors and as technical advisory group who will oversee this cascading,” she added.
She noted that the hospitals will be provided with equipment, test kits, supplies, and all other administrative costs they will incur during the pilot implementation that seeks to cover public market vendors and drivers.
“As pooled testing will be implemented, there will be a weekly review of the technical advisory group that will be formed in coordination with DoH and RITM. From there, they can either recommend to increase the pool or reduce the pool.”
She said parameters of pooling may vary depending on the area. “The recommendation of the number of people to be tested in Metro Manila will be different to those tested in provinces,” she explained.
During his presentation, Dr. Raymund Lo, head of the PCMC COVID-19 Testing Laboratory, said, "We are actually recommending pool size of five for faster turnaround time with comparable savings and the least drop insensitivity and that is our preliminary findings as far as the research is concerned.”
He said they also recommend that pooled testing be conducted in low prevalence communities for epidemiologic surveillance and aggressive contact tracing; mass testing in hot zones communities; surveillance of healthcare workers; workplace testing to include factory workers, market vendors, call centers, transportation workers, and others; and border testing at airports and seaports for inbound, foreign traveler, and returning residents.
He said the pooled testing should also cover Overseas Filipino Workers who are expected to be deployed overseas, the returning OFWs; frontline government workers such as police, military, quarantine, and immigration officers; locally stranded individuals (LSIs), and any other vulnerable population to be determined in the future.
Lo said during their research study, they have detected "a little drop in sensitivity, but that is to be expected as well as seen in the pooled testing studies abroad.”
"This does to negate the benefits of pooled testing. First of all, when you see drop in sensitivity, it is in the low viral load carriers of the virus and if we do miss them, remember we are testing a larger population now, and we will pick up many more than what we will be missing if we do not test at all. that's something we have to understand here. There is always a trade off in everything we do,” he said.
“We need to expand our testing capacity and this is one way of doing it. It is done in worldwide as well in many other countries,” he added.
Garin said pools of five for the pilot implementation is expect to be around P650 to P700.
"That is an estimated cost that will actually depend on the setting and prevalance,” she said.
She noted that the PSP and PCMC are recommending pools of five considering that there is no available data yet on the magnitude of the COVID-19 infection in the country.
“We also don’t have data yet whether the patients that we have are moderate to strong positives, or they are weak positive. Weak positive does not mean na sa pooling hindi makikita (that in the pooling, they will not be detected),ang (the) weak positive, puwede rin siya na hindi masydo madetect (cannot be detected) in other regular PCR testing,”she explained.
“What is being seen is that the 80 percent detection among low positives is still good enough because marami pong mga test ang hindi nakakadetect (there are many tests that cannot detect) ng (the) low positive, but in the procedure that they have done, 86 percent na nadedetermine (has been determined) among frozen samples with already low positive, kumbaga mas baba ang kanilang (meaning, they have low) viral load pero nadedetect pa rin (but can still be detected), 86 percent of the time is actually a reflection and a good test especially in pools of five,” Garin said.
Lo said alongside with the aggressive mass testing, there should be "very strong contract tracing” for the country to be successful in containing the virus.
“We will need very good contract tracing…We are seeing a lot of positives , they have not been contacted for contact tracing. For this to succeed, contract tracing is an important measure to address as well as the testing itself,” he stressed.
Garin said initially, the laboratories that will be allowed to conduct pooled testing will be the existing accredited COVID testing centers.
According to her, it will be the RITM that will approve the request. “They will have online approvals so that it will not take long, each laboratory kung bago ang kit ang gagamitin (if new kit will be used), we have a parallel validation so that we are sure that the specify kit can actually be applied for pooled testing.”