Health experts sceptical about ‘dilution’ of quarantine period

They attribute Kerala’s success till date to 28-day quarantine

Kochi/Kerala,08/05/2020.A passenger from the Abudhabi-Kochi flight that landed in Kochi international airport being shifted to an ambulance. Photo: H. Vibhu/The Hindu.

The government’s decision to divide the quarantine period — to institutional and home — for those returning to the State has created some confusion all around. Experts feel it hints at a dilution of quarantine norms. As information on COVID-19 is still evolving, they believe Kerala should stick to 28 days of quarantine.

If the returnees are in home quarantine in a green zone, where there are more concessions on movement and more shops are open, they might bypass the strict isolation norms.

The success Kerala achieved in the first two waves was because of the strict 28-day quarantine, says Dr. Padmanabha Shenoy, immunologist and rheumatologist. Reducing it to seven days in institutional care would not bode well as there is a likelihood of missing 25% cases, he says, quoting a study published on quarantine period effectiveness in the

Annals of Internal Medicine . Assuming that about five lakh Non-Resident Keralites will return in the next two months and the likelihood of anyone carrying SARS-CoV-2 to be 0.5%, there could be 2,500 cases, and 25% of these, which is about 650 cases, would be missed. Tracing the contacts of these people would be a big task, since the primary contacts could number around 30,000. In a 14-day quarantine, the numbers that could be missed would be reduced to 2%, which could be around 60 cases. However, if quarantine is imposed for 28 days, the chances plummet to 0.012%, which would mean missing just five cases. Why should the government give concessions on quarantine period, bringing it to 7+7 (institution + home), when there is a tested method that has proved good for the State, Dr. Shenoy asks.

Still ambiguous

Tinku Joseph, interventional pulmonologist, says there is no clarity yet on how long a person remains infectious. Quoting a study in

Lancet , Dr. Joseph says of 21 patients with mild illness, 90% gave repeated negative test results on nasopharyngeal swabs after 10 days of the onset of symptoms. In contrast, in another study of 56 patients with mild to moderate illness, the tests were positive for 24 days on an average (the longest being 42 days), he says, emphasising the need for a 28-day strict quarantine.

‘14 days will suffice’

However, pulmonologist A. Fathahudeen, nodal corona officer at Government Medical College, Ernakulam, says even in most developed countries only the very sick are being kept in hospitals. Here, all positive cases are hospitalised and are discharged only after their tests turn negative. Regarding the returnees, he says a test on the seventh day can pick up a likely positive case. Fourteen days of quarantine, as a combination of the institutional and home settings, is sufficient, he said.