Two days after issuing a circular, which allowed placing of international travellers into home quarantine if they had completed seven days of institutional quarantine, the Karnataka government has done away with previously mandatory COVID-19 testing for asymptomatic individuals.
A circular signed by Jawaid Akhtar, Additional Chief Secretary to the State Government, dated May 27, says that any “person who has completed seven days of institutional quarantine and is asymptomatic can be permitted for home quarantine without a COVID-19 test (RT-PCR), subject to undergoing a medical check-up.”
This check-up equates to thermal screening (with a required temperature of under 37.5C or 99.5F and pulse oximetry of under 94%).
The circular added that all elderly people, over the age of 60, and those with comorbidities (such as Diabetes mellitus, hypertension, asthma, heart ailment, renal disease...etc) are “required to be clinically evaluated diligently prior to shifting them for quarantine.”
On Wednesday, Pankaj Pandey, Commissioner, the Department of Health and Family Welfare told DH that these new guidelines were based on recommendations from the COVID Task Force.
A member of the COVID Task Force told DH today that new strategies had been formulated based on the latest findings on how the SARS-Cov-2 virus affects people.
The latest finding on how COVID-19 virus behaves
According to a white paper by the National Centre for Infectious Diseases and the Chapter of Infectious Disease Physicians, Academy of Medicine, Singapore, which aided the Task Force in formulating its new strategy, the infectious period of SARS-CoV-2 virus in symptomatic individuals may begin as early as two days before the onset of symptoms and persists for about seven to 10 days after the onset of symptoms.
This finding, the paper stated, was based on accumulated data since the start of the pandemic.
Another startling finding is that active viral replication is said to “drop quickly after the first week, and the viable virus was not found after the second week of illness despite the persistence of PCR detection of viral RNA.”
A study of 766 patients in Singapore also indicated that by day 15 from the onset of illness, 30% of all COVID-19 patients tested negative on RT-PCR tests using swabs samples taken from the nasopharyngeal area. This percentage increases to 68% by day 21, 88% by day 28 and 95% by day 33. The study determined that the detection of viral RNA through the RT-PCR method does “not necessarily mean the presence of an infectious or viable virus.”
However, the paper also cautions that “robust data is lacking regarding infectiousness of asymptomatic and pre-symptomatic individuals and how much asymptomatic infection drives the transmission.”
The problem of RT-PCR
In formulating its new guidelines, the Karnataka COVID Task Force also considered international studies which appear to indicate that countries, such as India, which use a policy of repeating respiratory sample RT-PCRs tests to determine if patients were negative for the disease, had resulted in some case where patients test positive again after being discharged.
At least two patients in Karnataka fall under this category. One is a patient in Belagavi, who was readmitted into COVID-19 care for an additional eight days after being given a clean bill of health following 19 days of hospital care in April. Another is a member of Bengaluru’s Hongasandra cluster, who went back into COVID-19 care despite being discharged with a clean bill of health after 17 days of hospitalisation from April to May. He was subsequently discharged after five days.