India’s Covid-19 testing is falling short – again. How big is the problem?

In the spring of 2020 when Covid-19 first hit India, one of the first things independent experts red flagged about the country’s response was inadequate testing. Over the next few months, every aspect of the country’s testing regime was dissected by the media, from the availability of test kits to the pricing of tests.

But as testing capacity expanded, these questions faded – until a second wave of the coronavirus pandemic hit India this year, overwhelming its Covid-19 testing infrastructure. Across cities and states, reports suggest people with symptoms of the disease are unable to get themselves tested, with labs fully booked and test reports significantly delayed. In many places, the lack of a Covid-positive report means seriously ill patients are unable to access hospital admission and oxygen cylinders.

Beyond the hardship caused to patients, what are the wider costs of the country’s sub-optimal testing?

India’s testing numbers

India has ramped up testing capacity exponentially since the pandemic began. From the 2,000-odd daily tests it was doing in March 2020, India now consistently tests above 15 lakh samples a day. In the past two weeks, there have been days where the number has exceeded 19 lakh.

Yet, compared to several other countries with a high caseload, it remains underwhelming. India’s daily testing rate of 1276 samples per million population is significantly less than most western countries.

To add to that, India’s positivity rate – or the number of positive cases per 100 samples tested – remains well above the recommended level of 5%. In fact, as of Saturday, 24 states have test positivity rates of over 10%, 16 of which are over 20%

This, some epidemiologists say, could be a sign of states testing only symptomatic people, hence leading to an undercount of infections. Given that positivity rates have sustained at higher levels for a prolonged time, it meant that transmissions were continuing unabated.

A stressed system

According to the Indian Council of Medical Research, the country has molecular testing capacity for around 15 lakh tests. These are RT-PCR or reverse transcription-polymerase chain reaction tests that are recommended for diagnostic purposes.

India’s RT-PCR testing capacity at the beginning of the pandemic in 2020 was negligible, with an acute shortage of laboratories and kits. While these were scaled, the country is now facing a shortage of trained personnel.

“At present, the laboratories are facing challenges to meet the expected testing target due to extraordinary case load and staff getting infected with Covid-19,” the ICMR said on May 4.

India is currently doing around 17.5 lakh tests a day. That includes molecular as well as rapid antigen tests, whose reliability is suspect. Though the numbers vary from state to state, rapid antigen tests form a sizeable chunk of the total tests in India. In a state like Bihar, for instance, which has a molecular testing capacity of 10,000 a day, rapid tests amount to as much as 90%.

The takeaway from this is obvious: India is not being able to take advantage of the more accurate RT-PCR technology, despite the physical infrastructure.

All of this points towards an irrefutable – but increasingly banal – fact: India is massively undercounting infections.

What should the country do, in a situation of limited resources and with burgeoning pressures on the treatment front? Experts interviewed for this story shared a range of opinions, but there seemed to be consensus about one thing: India’s current testing regime is not only presenting a distorted picture of the current situation, it is also making predictions of future trajectories difficult.

Test, test, test – to break transmission chains

According to Ranu Dhillon, a global health physician at Harvard Medical School and former Ebola adviser to Guinea, India’s testing was “far short of what is needed”. “Transmission has exploded exponentially while testing has only inched up by small increments,” he pointed out.

At the peak of the last wave when there were around 98,000 reported cases, India was doing nearly 11 lakh tests. Now while the number of daily reported cases has gone up by four times, testing has not even doubled.

“Without vastly more testing, there will be no way to meaningfully keep up with the pandemic, identify infections before they spread further or even properly diagnose and then treat those with symptoms,” said Dhillon.

In a situation where “most transmission chains are unknown”, he said it was imperative to be “testing population-wide in areas with transmission to find and break off spread”. “You have to assume anyone – including those without symptoms – may be infected,” said Dhillon.

Rijo M John, a health economist at Kozhikode’s Indian Institute of Management, has been a vocal critic of India’s sub-par testing numbers, putting out one Twitter thread over another in the last couple of weeks. “Since contact tracing is almost impossible to do, you have to do mass testing to try and break the chain,” he said over the phone from Kerala. “According to me, we should do 3-4 million daily tests.”

‘Strategic testing’

But there are epidemiologists who believe we need to be too bothered about the number of daily tests. Instead, testing ought to be “strategic” given our resource constraints, said Jacob John, a professor of community medicine at Vellore’s Christian Medical College.

“Remember we are not an island country with infinite resources,” said John. “When the resources are limited, you can’t be doing this [mass testing] for a long period of time. Maybe initially when you have hope you will stop the pandemic then it’s worth it, but that stage is gone.”

Testing, John said, served two purposes: diagnosis and public health interventions. It was needed in cases where treatment depended on the outcome of the test – for instance, people with comorbidities and severe symptoms who would require special interventions. The rest, he said, were supposed to follow the “generic approach” of isolation to not spread the infection further. “We know that it is a respiratory disease that spreads through contact and droplets,” he said. “So you wear a mask.”

The other purpose of testing was to determine “where in the pandemic we are”, said John. “That needs to continue and that should be done through very strategic random samples of the population that can be extrapolated to make meaningful change of policy,” said John.

Prioritising treatment

Chandrakant Lahariya, a public health specialist and epidemiologist in Delhi, had a similar view. He called for “judicious use of available resources”. “There is no limit really to testing, but for what purpose?”asked Lahariya. “We only have limited resources.”

Instead of focussing on an absolute all-India number, Lahariya said it made more sense to ensure testing was spread out well across geographies and in settings where caseload was currently low. He said there was little point in overwhelming labs in high-burden states where people with respiratory complaints were most likely to be infected. “Patient is presumed to be positive and treated as such,” said Lahariya.

Rajib Dasgupta, professor and chairperson, Centre of Social Medicine and Community Health at Delhi’s Jawaharlal Nehru University said while it was fairly obvious that India needed to do more tests, the current situation was “one of mitigation”.

“If the governments are forced to prioritise between competing demands such as testing, treatment and vaccination, the primary task is to augment capacities for clinical care and prevent mortality,” he said.

State officials say they are indeed having to prioritise. For example, mass testing camps that many states organised last year are being avoided this year in the favour of vaccination camps. “Last year, there was only one thing to do and the whole machinery was mobilised towards that,” said a health official of a state in eastern India, referring to Covid-19 testing. “But now there is also vaccination and treatment we have to focus on and resources at our disposal remain the same.”

Rapid tests

But Dhillon said testing and treatment were not unrelated. Treatment capacity, he said, was bound to “get outpaced by the numbers who are sick unless transmission can be slowed”. “When transmission is so widespread as it is now, the only way to find and break off transmission chains is to screen widely and frequently,” he said. “This includes people without symptoms so that they cannot infect others.”

He said he was cognisant of India’s limited resources, but said the country had to find ways to work around the problem. Deployment of rapid antigen tests for initial screening purposes – despite their somewhat unreliable nature – could be one of them, he said. “I think widespread deployment of rapid tests, ideally where people, even those without symptoms, can be screened every few days, could be the best and fastest way to expand testing given the situation,” he said.

These tests, he said, did not require very highly skilled professionals and India’s vast network of community health workers could be roped in to administer them.

The ICMR’s latest advisory issued on May 4 also makes a recommendation along these lines, suggesting that rapid antigen tests be used for diagnostic purposes, contradicting its previous stand. “RAT [rapid antigen test] has a short turnaround time of 15-30 minutes and thus offers a huge advantage of quick detection of cases and opportunity to isolate and treat them early for curbing transmission,” it notes. “It will be prudent to upscale testing using RATs.”

Not just a scale problem

But India’s testing regime had more than a scale problem, said John. There was no coordinated testing strategy, he pointed out, that could help make informed public policy interventions for the future.

Testing was not just about quantifying infections at a given point in time. “Testing should tell us when the future holds and forecast the resources and tools we would need to deal with it,” he said.

He suggested that governments focus their efforts on testing in “sentinel sites”, referring to people coming in to health care facilities. “Then you extrapolate that to the rest of the population to predict the trends for the rest of the country,” he said. “That will drive your public health action, whether it is lockdowns or something else.”

But that was not happening. “Right now we are just playing around,” he said.