The Health Department has issued new guidelines clarifying that a person who has recovered from COVID-19 and tests positive again on a subsequent RT-PCR (reverse transcription - polymerase chain reaction) test within three months of recovery should not be considered as an infectious patient.
Such PCR positivity on a retest, in an asymptomatic individual who had recovered from COVID-19 earlier, is just a case of persistent viral RNA (ribonucleic acid) shedding and should not be equated with infectivity, the department says. The clarification follows a lot of confusion from the field over COVID-recovered patients turning positive again in subsequent PCR tests.
The identification of SARS-CoV-2 RNA through the PCR test in an individual who has recovered from COVID should not be seen as the presence of viable, infectious virus. In mild cases, virus with a capacity to replicate cannot be cultured after 10 days and in moderate-severe cases, replicable virus cannot be cultured beyond 20 days. Within three months of recovery, PCR positivity does not indicate reinfection.
The department says retesting is not recommended within three months for persons who have recovered from an episode of the disease and who have been remaining asymptomatic.
If at all a person who has recovered is required to undergo testing again within three months – prior to a surgery, prior to election duty or prior to undergoing a dialysis – the test performed should be the rapid antigen test and not PCR. The guidelines underline that surgical procedures should not be deferred just because the PCR test of an asymptomatic individual who had previously recovered from COVID-19 turned positive again.
The department says prolonged and persistent viral RNA shedding had been documented in some patients for as long as 104 days from symptom onset. A subset of patients who have recovered from COVID-19 also gets intermittent PCR-negative results.
Persons who develop new symptoms consistent with COVID-19 within three months of recovery may warrant retesting if an alternative clinical reason cannot be found or if they had contact with a COVID-positive person in the past 14 days. Such persons should go into isolation while the test results are being evaluated.
The department also insists that serologic testing should not be used to establish SARS-CoV-2 infection or reinfection.
