City health authorities welcomed the issuance of the guidelines by the Department of Health for the use of antigen test following its pilot test in Baguio City.
City Health Officer Rowena Galpo said the successful pilot test of the antigen in the city led to the issuance of DOH Memorandum Circular 2020-0468 dated Oct. 26 prescribing the supplemental guidelines on the use of the rapid antigen test kits, following the recommendation of the World Health Organization and Health Technology Assessment Council, and the results of the pilot testing on close contacts of confirmed Covid cases and travelers in the city.
Based on the guidelines, rapid antigen test shall be allowed for diagnostic testing of close contacts in communities and closed or semi-closed institutions with confirmed outbreaks and in settings where reverse transcription polymerase chain reaction (RT-PCR) is not immediately available.
Antigen testing can be used as a confirmatory test among symptomatic close contacts.
The antigen test can be for asymptomatic close contacts, provided that the negative results are confirmed with RT-PCR or subjected to repeat antigen testing within 48 hours after the first negative test result.
The use of antigen test is not recommended in settings with expected low prevalence of cases or population with no known exposure, such as among asymptomatic travelers or for border control.
Antigen tests are most useful during the acute phase of the virus when the viral load of the patient is high, which is within five days after the onset of symptoms.
Based on the rules, a positive antigen test among close contacts is interpreted as a confirmed Covid case, but for asymptomatic close contacts who tested negative through rapid antigen test, the results of the confirmatory test, either through RT-PCR or repeat antigen test, shall be reflected in official DOH reports and tallies.
The collection and processing of the specimens should be done in a health facility setting, rural health units, hospitals, health facilities, and DOH-licensed clinical laboratories to ensure that appropriate conditions are in place to minimize risk in patients and health care workers.
In areas where access to health facilities is limited, collection may be done outside of a health facility provided that a trained health care worker conducts the specimen collection in appropriate conditions.
The DOH said only kits with a minimum of 80 percent sensitivity and 97 percent specificity are recommended for use.
The DOH through the Research Institute for Tropical Medicine shall regularly publish the list of test kits that have been validated by the institute and other designated facilities. – PIO release