Covid-19 outbreak: When will coronavirus epidemic peak in the country?
When will the coronavirus pandemic peak in India? That’s the question confronting India after China, for the first time in two-and-half months, reported on Thursday that it had detected no local infections the previous day, indicating perhaps that the pandemic has peaked in the country of its origin. To be sure, China faces the risk of a second wave of infections as the government eases restrictions put in place to contain the outbreak and people gradually resume normal lives.
India, according to the government, is still in the local transmission phase of the pandemic wherein the disease is restricted to people who have come in contact with infected foreigners or returning Indians who have been abroad and caught it in the places they travelled to.
There has been no community transmission and the hope is that it will hit the peak in the next two weeks and start to gradually taper; even so, it will linger on as an endemic virus, which could challenge the health-care system by resurging in the future. The less optimistic scenario is that India has to batten down for a long fight.
On whether the disease has peaked in China, in whose Wuhan city it originated at the end of 2019, scientists are divided. The optimistic view is that the infections have already peaked in China; a less rosy scenario is that it will only do so in May with 550-600 million people in the world’s most populated country infected by the virus.
An analysis by David Cyranoski of the science journal Nature quoted Zhong Nanshan, a Chinese physician leading a committee on the outbreak, as saying on February 11 that the coronavirus would peak in China by the end of February.
Zhong, who is famous for discovering the virus that causes Severe Acute Respiratory Syndrome (Sars), said the situation had improved because of interventions such as travel restrictions. But other research suggests infections may rise again with the lifting of the restrictions.
People in Chinese cities started returning to work last week which could lead to new chains of transmission according to Hiroshi Nishiura, an epidemiologist at Hokkaido University in Sapporo, Japan. Infections could peak between late March and late May, he said, and estimated that between 550 million and 650 million people across China are at risk of being infected, roughly 40% of the country’s population.
Gabriel Leung, an epidemiologist at the University of Hong Kong, says the community has no immunity to Sars-CoV-2 and hence it will sweep through.
Epidemiologists fear that India is in for the long haul with a brief peaking in places where cases have been recorded and then spreading across the country.
“We have data only from China, Italy, Spain and Germany. In the beginning infection spread was slow in these countries. There was a slight increase in cases when infected travellers came in contact with local people. In Italy, cases jumped from a few hundreds to several thousands of cases within about a fortnight. That was the jump from local to community transmission. Whether there is community transmission in India, there is no evidence yet. But we have to take it with a pinch of salt because we are not doing widespread testing,” said Amit Singh, associate professor, Centre for Infectious Disease Research, Indian Institute of Science.
“We have to go into surveillance mode to understand that. In South Korea they went into the community and did extensive testing. But do we have enough testing kits to do that right now? Do we have reagents to do such large-scale testing. We are such a dense country and for a certain section, people live so close to each other. We have to prepare aggressively to contain this before it becomes uncontainable,” warned Singh.
Dr T Jacob John, veteran virologist, emeritus professor at the Christian Medical College, Vellore and former head of the Indian Council for Medical Research’s Centre for Advanced Research in Virology, echoes the concern.
“This is a new virus, so prediction may not be correct. I can tell you how microbes behave. It’s a respiratory transmitted virus which catches with social contact. So we anticipate that it will spread widely which means it could range from 10% to even 40% of the population. We should expect the worst-case scenario and be happy later that it didn’t turn out to be so. With time, the rising curve will be steeper.”
“Don’t expect a tsunami but expect an avalanche. We should make use of every single day right now,” he cautioned. “I was expecting [that] from February 1, we would have a systematic building up of ICUs [intensive care units], ventilators, protective gear infrastructure and training of doctors. I was expecting a unified policy statement but we haven’t heard that from the Centre.”
Another public health expert, who is associated with a prominent research organisation, said on condition of anonymity: “Everything depends on how well we are able to contain community transmission. You have read so much,seen so much on social media about the flattening of the curve. So we have to see how much we can flatten that curve with interventions like social distancing.”
“We are not like a small European country. Chikungunya lingered almost for a year. In some parts it spread only in the next season. The H1N1 [swine flu] outbreak became endemic after two to three seasons but the tail lingered. So this virus too may become endemic. But some habits have to change permanently like personal hygiene, washing hands, no spitting etc.”
Severe cases of respiratory infection need to be tracked and documented now to ascertain community transmission, the expert suggested.
“...are we testing suspected cases? How many of them are there? Do we know if there is an increase in severe acute respiratory infections (SARI). If those numbers are going up there may be community transmission already. Our surveillance has to be strengthened and admissions with SARI will have to be notified,” he added.