After the Centre announced on April 29 that stranded workers could go back to their home states, Bihar, one of India’s biggest intra-country exporters of migrant workers, is witnessing a surge of people returning home.

According to a senior official in the state disaster management department that is overseeing the repatriation, almost 45,000 people would have arrived just on trains by Thursday evening. “In addition, we are seeing around 3,000 people coming in through the various land borders every day,” said the official.

In other words, at least 70,000 people have arrived in the state since April 29.

Yet, the state’s testing numbers have sharply dipped starting this week. Since May 4, the state had tested 2,316 samples over four days. That is an average of 579 tests per day.

The corresponding number for the previous four days, April 30-May 3, was 6,043 – a drop of more than 60%. During these four days, the state tested more than 1,500 samples a day on average.

Strikingly, the state had tested more people on May 1 itself than in three days between May 4-6.

At less than 300 people per million, Bihar’s testing rate is one of the lowest in the country.

A drastic dip in tests

Starting April 23, the state’s testing graph had been rising with more than 1,000 samples tested every day. Barring April 25 when 953 samples were tested, the numbers did not fall below the 1,000-mark until May 4.

The sharp decline since May 4 is in stark contrast to the national trend and even other neighbouring states like Jharkhand and Odisha that have also received a large number of migrants over the last week and a half.

‘Temporary blip’

State authorities insist the drop in testing number is a “temporary blip” because the state was in the process of “finalising a new testing strategy” for the incoming migrants.

“It will go up again over the next few days,” said Sanjay Kumar, who heads Bihar’s health and family welfare department.

On Friday morning, Kumar tweeted that the strategy had been finalised. As reported earlier in the day, the state will now conduct random tests of asymptomatic individuals who had come in from other parts of the country.

‘Contact tracing over’

Health officials in the state said the recent dip was largely a result of not finding too many new cases in the first few days of May.

As Bihar saw a sharp surge in positive cases in the last ten days of April, the state ramped up testing. Several contacts of positive patients were tested, resulting in high testing numbers, said Raj Kishore Chaudhary, Patna’s civil surgeon who is charge of testing in the district. “All contacts of those people have already been traced, isolated and tested,” said Chaudhary. “Now that there are new positives, intensive testing will begin again.”

As of noon on May 8, Bihar had reported 556 cases of Covid-19. Five of them had died.

Guidelines of the Indian Council of Medical Research, which is overseeing India’s response to the pandemic, state that contacts of laboratory-confirmed tests need to be screened. While the low-risk contacts are to be home-quarantined and tested only if they show symptoms, high-risk contacts such as immediate family members and closely attending healthcare workers have to be mandatorily tested irrespective of clinical manifestations. Another category of people who have to be compulsorily tested: hospitalised patients who exhibit pneumonia-like symptoms.

The ICMR also recommends the testing of patients with mild flu-like symptoms in hotspots, clusters, and “large migration gatherings/evacuees centres”.

‘Can’t find symptomatic people’

However, Bihar officials said they were struggling to find people with symptoms despite carrying out door-to-door surveys. “We have surveyed 3 crore people, but have barely been able to find symptomatic people,” said Kumar.

This fits in with the pattern of cases, said the official, noting that more than 85% of the confirmed cases in the state were asymptomatic. “ICMR’s testing strategy is largely based on symptoms,” he said. “But in Bihar there are not many people with symptoms, so we just were not being able to find enough samples.”

Thus, the low testing numbers and the decision to conduct random test of asymptomatic migrant workers who have arrived from other states, said Kumar.

Resource crunch

But it could be more than just the lack of eligible candidates leading to a decline in testing in Bihar. While the state’s six labs have a combined capacity to conduct around 1,700 tests a day, it is somewhat hard-pressed for other resources. Currently, while the state has kits to conduct 50,000 tests, it has RNA extractor kits for just 15,000 tests, said Kumar.

The extraction of genetic code in the form of the single-stranded RNA from the swab sample is the first step in a RT-PCR or reverse-transcriptase polymerase chain reaction test that most countries including India are using diagnose the novel coronavirus.

“While ICMR supplies the kits, we have to purchase our own RNA extractors,” said Kumar. The state procures them from a firm in Singapore, but Kumar said the “supply chain is broken”.