RT-PCR tests no longer necessary for Covid-19 patients: state medical dept


The Department of Medical Sciences announced on Monday that patients who test positive with ATK do not have to also undergo an RT-PCR test, because it is expensive and takes longer.

Suphakit Sirilak, the department’s director-general, said the Covid-19 situation has changed and testing technology has also improved.

Hence, the department has issued new guidelines for Covid-19 tests:

• Proper samples should be collected for both RNA (RT-PCR) and ATK tests. For ATK tests, samples should be collected via a nasopharyngeal swab or saliva. For ATK tests at hospitals, samples should be collected via nasopharyngeal swabs, while nasal swabs or saliva can be used for ATK testing at home.

Suphakit advised that saliva should be collected immediately after waking up from deep inside the throat. The sample should be taken before brushing the teeth or using a mouthwash. If taken at other times of the day, the patient has to avoid eating or drinking for at least an hour.

He also said that hard swab sticks should not be used on children and instead recommended collecting saliva.

• For RNA tests, the initial criteria was that it should detect at least <1,000 copies/ml of more than one gene of the virus or a gene in more than one position.

Initially, only the RT-PCR (polymerase chain reaction) test was accepted, but now there are also RT-LAMP and CRISPR technologies. These new tests are faster but still need the Food and Drug Administration’s approval.

• Patients with mild or no symptoms who have tested positive via ATK tests should enter home or community isolation systems or be treated as an outpatient. If they develop severe symptoms, they can undergo an RT-PCR test before being treated in hospital.

If they test negative using ATK, then they do not have to quarantine. However, they are advised to test again in three days or if they develop symptoms.

• RT-PCR tests will be used at international checkpoints, though machine-based assay ATK tests or faster RNA tests that use large batches are also acceptable.

Suphakit said people do not have to undergo an RT-PCR test after an ATK test because the Omicron variant is not severe. However, patients with chronic diseases who may be at risk should see a doctor and undergo an RT-PCR test for treatment in the hospital.