India’s coronavirus epidemic is beyond any prospects of containment at multiple sites that have widespread transmission or high infection prevalence rates and where health authorities have quietly turned their focus to curbing deaths, experts have said.

Public health specialists and epidemiologists say that efforts to contain the infection through measures such as contact tracing made sense during the early stages of the epidemic but are fatigue-inducing and wasteful in areas with widespread transmission.

The Union health ministry had earlier this week urged 10 states, including Bengal, to focus on “containment, contact tracing and surveillance” among the actions required for early diagnosis, effective treatment and mortality reduction among Covid-19 patients.

The advisory also asked the states to ensure that at least in 80 per cent of the new Covid-19 cases, all the close contacts were “traced and tested” within 72 hours.

Contact tracing helps identify and isolate people who might be infected to prevent further spread of the infection.

But the scale of the epidemic at many places, experts say, would render containment efforts futile.

India on Sunday recorded 78,761 new Covid-19 cases, including 16,286 in Maharashtra, 8,362 in Karnataka and 3,012 in Bengal — three of the 10 states that account for 89 per cent of the mortality.

The average daily number of new cases over the past week has been 71,113. If every new positive case had only three contacts, field health staff would need to trace and test over 210,000 people every day.

When there are hundreds or thousands of new cases every day, contact tracing will cause fatigue with little impact, said Sanjay Rai, professor of community medicine at the All India Institute of Medical Sciences, New Delhi, and president of the Indian Public Health Association.

Surveys in Ahmedabad, Delhi, Mumbai and Pune have suggested that 17 to 51 per cent of the sampled populations in some localities had been infected by the coronavirus, pointing to widespread transmission that has been invisible or not accounted in the daily Covid-19 counts.

“The response in such circumstances should focus on mitigation — or efforts to minimise deaths by ensuring that every patient who needs hospital care gets the best care possible,” Rai said.

“Testing all contacts would be wasteful. Resources should be conserved to improve and expand the treatment facilities.”

India’s number of Covid-19 patients under medical supervision on Sunday was 765,302, the second highest in the world after the US, whose corresponding figure is over 2.5 million.

Some epidemiologists say the successful containment achieved early in Kerala and at Dharavi in Mumbai probably raised expectations that similar feats would be possible across India.

Kerala was the first state to detect a coronavirus case on January 30, and used rigorous contact tracing and quarantine to keep the daily number of infections below 100 till early June. The number has grown since then and the state on Sunday recorded 2,397 new cases.

“There’s nothing surprising about the rise in numbers, whether in Kerala or elsewhere — this is the nature of this coronavirus,” said Jaiprakash Muliyil, a community medicine specialist and former principal at the Christian Medical College, Vellore.

“Kerala did a fantastic job, a superhuman effort to help keep infections low as long as it was possible. But Kerala’s early success created an impression that it was possible to contain the virus.”

Health authorities working alongside local doctors in Mumbai also helped achieve a steep decline in the number of new infections in Dharavi — from a daily average of 43 in May to one of 19 in June to single-digit numbers in August.

They adopted standard public health measures — contact tracing, testing suspects, isolating patients and moving vulnerable elderly people to temporary shelters away from the infection’s hot-zone.

“What Dharavi did demanded huge amounts of effort and determination,” said Oommen John, a public health expert at The George Institute for Global Health, New Delhi. “It is unrealistic to expect the model to be replicated everywhere else.”

Some experts argue that India has pursued both containment and mitigation simultaneously.

“It doesn’t have to be a choice — one or the other — we’ll have to ride both horses depending on the ground situation,” said Tarun Bhatnagar, a senior clinician-researcher at the National Institute of Epidemiology, Chennai, a unit of the Indian Council of Medical Research.

“A lot of effort has gone into preparing health facilities for Covid-19 patients and trying to ensure that the patients receive effective treatment,” he said. “Given the state of our health system, India has thus far done much better than it might have,” Bhatnagar said.

Health officials have attributed India’s declining mortality rate among Covid-19 patients — from 3.3 per cent in mid-June to 2.7 per cent in mid-July to 1.79 per cent on Sunday — to early diagnosis and effective treatment.

But health experts expect the epidemic to continue to pose severe challenges.

“It’s bound to grow,” said D.C.S. Reddy, a senior epidemiologist in Lucknow and member of an ICMR task force on epidemiology and surveillance.

“The key to effective response lies in recognising what is going on at the local level. The response should be tailored to local situations.”

Contact tracing and containment efforts will remain important in areas where the infection is still emerging, for instance, across rural areas or clusters of villages with few infections.

But in areas with widespread transmission, Reddy said, the appropriate response would be mitigation and personal protection measures such as masks, physical distancing and hand hygiene.