In my last Monday’s column, I wrote about the conflicting results of the reverse transcription-polymerase chain reaction (RT-PCR) or swab test and the saliva test introduced by the Philippine Red Cross (PRC). A Cebu City-based company employee was found positive in the saliva test, but negative in a swab test. When he volunteered to isolate himself, he was not admitted at the community isolation center of the local government unit (LGU) where he is residing. He was told that the LGU’s health officials would not acknowledge and recognize the saliva test. Yesterday, I was furnished copies of the Covid-19 conflicting results of a resident of Pinamungajan, which was opposite to the first case. The patient underwent a swab test in a private hospital last Feb. 16 and was found positive. Two days after, he underwent a saliva test of the Red Cross and was found negative.
Very confusing, indeed. But who am I, who have no medical knowledge, to question the conflicting results? In reaction, Maria Vera de Jesus, administrator of the PRC Cebu chapter, in her letter to this columnist, explained the different procedures and the accuracy of the two tests.
“I would like to reiterate matters and clarify doubt on the credibility and reliability of the Saliva RT-PCR including the disposition of the LGUs through the ‘directive’ from the DOH (Department of Health) based on the report and queries that we have been receiving since Day 1 of rollout:
1. The saliva test, which is self-collection that we have conducted, is an RT-PCR gold standard itself and does not have any difference from the accuracy of swab test. The only difference is that the latter requires collection of samples from throat and nose while the former requires saliva for specimen. They are both laboratory-based and do not need confirmatory test;
2. Before it was implemented and rolled out by the Philippine Red Cross, thorough study and tests were conducted since September when a parallel, concordant swab testing was done with the RT-PCR saliva testing and yielded a result of 98 percent accuracy;
3. The Department of Health has approved and acknowledged the Saliva RT-PCR of the Philippine Red Cross; a letter dated Jan. 21, 2021, was sent to the PRC thru its Chairman and CEO Sen. Richard J. Gordon, to that effect. (Copy of letter is attached hereto). No pending studies have to be done by the PRC; it is completed leading to its approval. This was likewise posted in its website.
4. With the approval from the DOH and its recognition, DTI even followed it and released an advisory regarding the legitimacy of the use of Saliva RT-PCR in knowing the status of individuals.
5. In furtherance of the acknowledgment, FDA posted in their website too that only PRC may administer the Saliva RT-PCR Test. This is credited too to the studies that our skillful team has conducted since September 2020. (For full text, visit: www.sunstar.com.ph)