'We are moving fast towards the peak of the epidemic'

Unsurprised by the rising numbers, epidemiologists are concerned about the virus reaching rural and tribal areas where the health infrastructure is weak, reports Ruchika Chitravanshi.

India has witnessed a storm surge in coronavirus cases that epidemiologists expect will continue for a few weeks, placing the country on a long road to reach from the pandemic to the endemic stage, when the number of cases decline and stabilise. (A pandemic is spread across multiple countries or continents, while an endemic is restricted to a particular population or geography. In the latter, the disease is present in a community at all times but in relatively low frequency, such as chicken pox.)

Data from the first national serosurvey has suggested that the actual cases, which are going undetected, are 20-30 times what has been reported. Even then a large part of the population still remains susceptible.

“If things continue this way, the national peak is nowhere near. As one state subsides, the other comes to a boil. You take your feet off the brake, the virus soars through the roof,” says Bhramar Mukherjee, professor of biostatistics, University of Michigan.

The test positivity rate has reached around 8.6 per cent. While the government wants to bring this number down to at least 5 per cent through increased testing, experts feel the rise in cases is not so much due to testing but more because of increased mobility, fatigue with rules, and lack of compliance with social distancing and mask wearing.

It took India almost six months to reach the first million Covid-19 cases. The last million took less than two weeks, making India’s tally the second highest in the world. India now has recorded over 5.4 million coronavirus cases.

“We are moving fast towards the peak of the epidemic. But we are unable to detect the infection. Our efficiency in detecting infections is inversely proportional to the massiveness of the epidemic,” says Jacob John, retired virologist and former head of the Indian Council of Medical Research’s Centre of Advanced Research in Virology.

John adds that even after we reach the peak, which he expects in the next three weeks, we would still be battling the pandemic as most cases will come up post-peak.

“Most people will be infected in the post-peak period of the epidemic. The advantage is that it will take longer for the virus to reach the remaining population.”

According to epidemiological models, the post-peak period should be one-and-a-half times the period it took to reach the peak. “If pre-peak period is five-six months, the projection of the epidemic profile shows that post-peak would be 8-10 months.

"It never touches the baseline,” John adds.

For example, diseases such as influenza, which came in the 1960s, or the H1N1, which came in 2009, are still around us. The only way out of the endemic stage is mass vaccination, experts say. Until such time, virologists say that the coronavirus will be among us and may become a seasonal infection that goes up and down.

Countries such as Germany, experts believe, have reached the “valley” of the curve, registering around 1,000 cases and less than 10 deaths a day for the last month after peak levels of April.

“In India, where each state is like a country experiencing its own version of the pandemic, the epidemic grew in April. The trajectory has been different in different parts of the country, plus the lockdown did slow down the spread between states,” John says.

However, if the results of the national survey are to be extrapolated, then India may have crossed 6.4 million cases in May itself, which makes it the worst hit country in the world.

If the actual cases were 20 times higher than the reported figure of 4.65 million, India is not out of the woods yet as a relatively small fraction of the population is infected.

In some cities, such as Delhi, cases have risen with a much higher intensity in the last month after declining in July.

“It is getting worse and worse each week, but a large part of the nation seems to have made the choice to ignore this crisis. (Is it) habituation, desensitisation, adaptation, fatigue, fatalism or denial? Perhaps all of these,” Mukherjee says.

Many epidemiologists are not surprised with the rising numbers but concerned about the virus reaching the rural and tribal areas where the health infrastructure is weak.

“This is a real concern,” adds Rakhal Gaitonde, professor, Sree Chitra Tirunal Institute for Medical Sciences and Technology, Trivandrum. “Also, Covid-19 is crowding out the other health services such as routine antenatal care, TB care, nutrition.”

• The War Against Coronavirus