On May 12, as Maharashtra chief minister Uddhav Thackeray addressed district authorities in a video-conference, he reportedly said that some districts in the state could try emulating the “door-to-door” model followed by neighboring Goa to identify suspected cases of Covid-19.

In mid-April, Goa employed ground-level workers to survey its entire population of around 20 lakh people. Based on travel history and clinical symptoms, the state identified 5,000 people to be tested.

India’s testing protocol, centrally set by the Indian Council of Medical Research that is overseeing the country’s response to the pandemic, has been largely restricted to hospitalised individuals with advanced pneumonia-like symptoms – apart from close contacts of laboratory-confirmed patients. The council recommends the testing of people with influenza-like illness only in disease hotspots and containment zones.

According to the World Health Organisation, a patient is classified as case of influenza-like illness if they have a fever greater than or equal to 38 C° and a cough, which began in the last 10 days. If such a patient requires hospitalisation, they would, however, be a case of severe acute respiratory illness or SARI.

Goa’s approach is, therefore, a departure from the ICMR protocol – it included people with influenza-like illness as opposed to only hospitalised pneumonia patients that the ICMR recommends for the general population.

In fact, increasingly as it appears that India has reached the community transmission stage – despite the union health ministry’s repeated denials – more and more states are surveilling their populations for influenza-like symptoms to detect cases of Covid-19.

The southern state of Andhra Pradesh has done several rounds of door-to-door surveys to identify over 32,000 individuals with influenza-like symptoms as well as people with travel history. The state has tested the people identified in these surveys in tranches: beginning with people with travel history, followed by those with symptoms, but no travel history.

Jharkhand, too, is going door-to-door. A decision to test is taken on the basis of travel history and symptoms, said the state’s National Health Mission head, Shailesh Kumar.

A symptomatic approach in Assam

While Goa, Andhra Pradesh and Jharkhand used the surveillance to identify people with travel history, some eastern states are sending volunteers door-to-door solely to identify people with unreported fever-like symptoms and pneumonia (severe acute respiratory illness).

In Assam, community health workers, lab technicians and doctors have fanned out across the state. The program, which began on May 7, targets to visit more than 25,000 villages of the state, according to the state’s health department. “We are all testing all people with influenza-like symptoms and SARI [Severe Acute Respiratory Infections] for Covid-19,” said Lakshmanan S, who heads the state’s National Health Mission. “For other fevers, we are testing for malaria and Japanese Encephalitis.”

While the doctor on the ground would take the final call on people with mild symptoms, Lakshmanan said the aim was to target everyone with fever and respiratory troubles. “That is the target for the time being,” he said.

The exercise is modelled around a three-day cycle. “The first day, the community health workers go house-to-house and identify cases with help from the village headman,” said Tirtha Nath Sarma, who heads the health department in Lower Assam’s Barpeta district. “The next day, doctors go and evaluate which cases should be tested for what, if at all. Finally, on the third day, the laboratory technician goes and collects blood or swab samples as is the case.”

In the first week, the state found less than 8,000 eligible samples in the 10,000 villages surveyed. The test results are pending.

The Bihar conundrum

Bihar did something similar starting April 16 in 13 districts – it sought to hunt down all unreported “symptomatic cases” in these districts. Symptomatic was defined as fever, cough, cold and breathing difficulties, said Ragini Mishra, the state’s nodal officer for Covid-19.

The state used the polio micro-plan to implement the survey. “That is a ready-made template for house-to-house surveillance,” said Shabnam Sultana, the Ayushman Bharat program officer in Nalanda district who was closely involved in the exercise.

A two-member monitoring team covered around 35 homes every day, said Sultana. Around 5% of the people surveyed were found to have some or the other symptom.

“Everyone with symptoms were asked to report at the nearest primary health centre,” she said. “There we would take a decision on whether to test based on severity of symptoms, contact, travel history, etc.”

Among the ones finally tested, not even one person turned out to be positive, said Sultana.

In Begusarai district, health workers could find even fewer symptomatic people. Less than 440 people of the 2.51 lakh people in the district exhibited any symptom at all, said Kunal Kumar, district community mobiliser in Begusarai. Among them, 300 people were finally tested for Covid-19. Like Nalanda, not even a single sample came out positive.

This trend reflects in the overall numbers in the state. According to Mishra, out of the 3 crore people surveyed, less than 1% were symptomatic. “Barely two-three people turned out to positive finally,” said Mishra.

In a similar month-long survey spanning over 5.5 crore households across the state starting April 3, West Bengal, too, could identify only 90,000 unreported cases of influenza and pneumonia. Of them, 62 of them tested positive for Covid-19.

Health workers wearing protective gear walk past sheep as they arrive to conduct a door-to-door verification in Ahmedabad. Photo: Reuters/ Amit Dave

In theory and on the ground

Are symptomatic people falling through the cracks because the system seems to be largely reliant on self-reporting?

While officials in Bihar and Assam insist that the process is fairly fool-proof, despite the somewhat unrealistic numbers, accounts from other states which have used a similar strategy to identify symptomatic people from its general population suggest otherwise.

For example, consider Maharashtra. Contrary to what Thackeray’s address to district officials earlier in the week may suggest, the state has, in fact, been doing door-to-door surveys – but they exist “merely on paper”, doctors say.

“When the Asha [Accredited Social Health Activist] goes, people hide their symptoms,” said a doctor who mans a public health centre in rural Pune. “Later the same person who had said that she was fine during the home visit would go to the Asha’s home and ask for flu medicines.”

Even if people report their symptoms, few actually go to the swab collection facility to get themselves tested. “From the village I serve in, you have to go almost 70-80 km,” said the doctor. “I have so far recommended 11 people from my village to get tested, but no one has ended up going. We can’t force them to go.”

The doctor said follow-ups were not possible as medical staff were now largely involved in screening coming from Mumbai and other high-risk areas. “Unless we make it convenient for samples to be collected in the field, this will not work practically.”

As pointed out earlier, the system in Assam provides for collection of samples from people’s homes. Bihar, like Maharashtra, requires people to go to the block-level medical facility. “If the symptoms are too severe, we send an ambulance or sometimes even the doctor goes,” said a state official.

A worthy endeavour?

If the door-to-door surveys are not working on the ground as state officials claim, are they an unnecessary strain on limited state resources?

“The direction of the idea is excellent,” said virologist T Jacob John. “But you have to choose the clinical criteria smartly. You have to look for symptoms of Covid-19, not influenza. They are two different conditions.”

What John means is: Covid-19’s clinical manifestations are unique and while they may be similar to influenza, they are not necessarily similar. “Every disease has a very specific set of clinical criteria,” said John, “and our doctors need to learn to identify them.”

If the clinical criteria are chosen well, the advantages of a door-to-door are many, said John. “That way you can diagnose more people with fewer test kits,” he said. “And once they are identified, you can follow their contacts.”

Giridhar R Babu, professor and head of life course epidemiology at the Public Health Foundation of India, also endorsed the door-to-door approach. The “syndromic approach” that these surveys employ was a focused way of detecting cases, Babu said. “I think every state should do it.”

Syndromic approach, which was adopted to identify HIV cases, for instance, is based on identification of consistent groups of symptoms and easily recognised signs.

But not all epidemiologists agree. “Our resources are limited, so what would be smarter would be to do more focused surveillance among people coming to hospitals, or say, pregnant women,” said Tarun Bhatnagar, scientist at the National Institute of Epidemiology, a unit of the Indian Council of Medical Research, and a member of high-level committee that is spearheading India’s response to the pandemic. “Then if the need be, you can do a second round of door-to-door in certain areas based on the findings of the first round.”

States doing it, though, insist that that door-to-door surveys are worthwhile investments. “We might not have been able to identify as many cases we had thought, but it turned out be a great exercise is building community awareness,” said Mishra, Bihar’s nodal officer for Covid-19.

Lakshmanan, Assam’s national health mission director, agreed. “Detecting Covid is only 25% of the survey’s purpose. The larger purpose is to check if people are following home quarantine,” he said. “A doctor going to the field will create a feel of confidence and awareness – and that is a huge requirement right now.”