Two recovered patients were readmitted after testing positive for COVID-19 again.
However, Dr. Marie Yvette Barez, infectious disease specialist of the Southern Philippines Medical Center (SPMC), said that the results could be considered as a false positive.
“These two patients were readmitted because they were found to be positive again after their 14 days of home quarantine. But they have improved and asymptomatic already,” she said.
Retesting positive for the virus is not new. China and Korea already reported cases of recovered patients who were flagged after follow-up tests. The Korea Centers for Disease Control and Prevention has observed no indication that they are still contagious. However, few studies have been done to confirm that observation.
She said that the findings do not automatically mean a relapse since the two patients showed no more symptoms.
Barez also explained the possibility of a false test result from the Polymerase Chain Reaction (PCR) machine.
She said PCR testing can detect even those dead or non-viable viruses. She said a virus can only be declared as 100-percent dead through a process called a viral culture. At present, the city has no such facility.
“This was also the experience of my colleagues in Manila that there are patients who show readings like being negative now, then becoming positive with COVID-19 later and then another test was conducted saying that the person is negative again,” she said.
She also said that PCR is not a good test for a cure since its expertise is testing for diagnostics. “It is the reason why we are only observing these patients to make sure that they have actually recovered,” she said.
As a standard health protocol, recovered patients were retested to ensure that they are absolutely cleared from the disease, and they will be allowed to go back to the community again.
Barez said that one patient is a healthcare worker who is no longer showing any symptoms. But the patient was sent home for a week for self-quarantine.
Another health worker was confined in one of the COVID-19 centers.
“The person underwent two tests, a protocol before a health worker returns to work. This person had a dry cough but showed negative results in his checkup. It had no symptoms but was confined outside the center for close monitoring,” she said.
Amid the complaint of this patient of an occasional dry cough, Barez said that all of his test results were normal, including the chest X-rays and other required tests.
“There were no antibiotics were given to the patients. The patients were admitted at a COVID-19 center for close monitoring,” she said.
She said that as long as the patients do not manifest symptoms like cough, colds, chest X-rays and other common tests show normal readings, the patient will be sent home.
Barez recommended the employment of a rapid detection test, but she said that locally it does not have local validation yet. It is still being validated by the Research Institute for Tropical Medicine in Muntinlupa and San Lazaro Hospital in Sta. Cruz, Manila.
“The test is good for the detection anti-bodies,” she said.
She also recommended another testing, which is to determine the level of the antibodies in COVID-19 patients. But it is not available in the country. “A presence of antibodies guarantees the presence of immunity for the patient,” she said.
She said some studies will still be conducted as many questions like how long will the antibody last prevails.