Covid-19: What you need to know today
In April 18, Delhi identified 186 new cases of the coronavirus disease (Covid-19). All 186 were asymptomatic. It’s possible that some asymptomatic people develop symptoms after some time. It’s equally possible that some don’t. Research from Italy has shown that the viral load in some asymptomatic patients is as high as that in patients with severe Covid-19 symptoms. The viral load is the quantum of virus found in a sample taken from a person. It is an indicator of the virus’ ability to replicate. A high viral load means it is replicating well. But there’s also research, including one published in The Lancet, that shows that patients who get severe infections tend to have a higher viral load of Sars-CoV-2, the virus that causes Covid-19.
While our understanding of the virus and its effect on the human body will become better in time, it is safe to surmise that not everyone reacts to a Sars-CoV-2 infection the same way.
One of HT’s photographers in Mumbai tested positive for the virus, but is asymptomatic. The local health officials have isolated him in a hotel — he is not unwell at all, and doesn’t need hospitalisation. The four HT employees who came in touch with him have been labelled low-risk contacts by the health officials and asked to go into self-quarantine. The office itself has been shut and is being deep-sanitised. He is well, in no discomfort, but is infected.
On Monday, the health ministry said in its daily briefing that 80% of people infected by the virus in the world show either mild symptoms or none at all. The ministry didn’t comment on India specifically on Monday, but the fact that it brought up the issue seems to suggest that the situation isn’t very different here. On Tuesday, the Indian Council of Medical Research said that 69% of all Covid-19 cases in India did not show symptoms at the time of testing; it did not specify whether they developed symptoms later.
People who are asymptomatic may still retain the ability to infect others because they carry the virus — potentially making them dangerous, especially to old people who may not be able to fight off the disease.
Data on fatalities in India show that around 75% are over the age of 60 (of which around 40% are over the age of 75). While the rest of India may, over time, develop herd immunity to the virus, this is the population that has to be protected — till a cure or vaccine for the virus is found, or, as epidemiologist Ramanan Laxminarayan wrote in this paper last week, 65% of the population develops herd immunity (which pretty much reduces to nothing the virus’s chances of jumping from person to person till it finds one over the age of 60).
India will have to open up sometime. A lockdown, according to some studies, reduced R0 (R naught) to less than one. R0 is a measure of how infectious a disease is; it is expressed in terms of the number of people likely to catch the disease from one infected person. Most scientists who have studied Sars-CoV-2 say it has an R0 of around 2.2. Still, it will not be possible for any country to stay locked down for months on end.
As India considers opening up, it will have to protect its most vulnerable population — 104 million people over the age of 60 (according to the 2011 census). That number is sure to have increased by now. Six states, Uttar Pradesh, Maharashtra, Bihar, West Bengal, Tamil Nadu, and Rajasthan accounted for around 54% of all people over the age of 60 in 2011. The list shouldn’t surprise anyone. These are the most populous Indian states. Another 15% were in Karnataka, Madhya Pradesh and Gujarat.
Since census data is collected at a disaggregated level, it should be possible for the government to identify within these nine states that account for seven out of every 10 people over the age of 60, cities and districts that are especially vulnerable because they have a high proportion of people over the age of 60, 70, or 80. These areas should consider stricter-than-normal social distancing measures, perhaps special guidelines on interacting with senior citizens; maybe even mandatory self-quarantines for such people. That will keep them safe and allow the rest of India to carry on.