On Saturday, Tamil Nadu health minister C Vijayabhaskar said that the state had tested 79 samples for coronavirus infection till March 14, out of which 78 were negative and one was positive.

This led to a flurry of responses on social media with many complaining that they had been unable to get themselves tested for Covid-19 infection in government hospitals in the state – despite having symptoms and travel history to countries with an outbreak.

What sparked more concern in Tamil Nadu was the sharp contrast with other southern states: Kerala had tested 1,897 samples, Karnataka 731 and Telangana 353.

In an interview with Scroll.in, Tamil Nadu’s director of public health and preventive medicine Dr K Kolandaswamy, defended the state’s low number of tests. He said Kerala saw more travel from coronavirus-affected countries which is why it had detected more cases. “When you have more positive cases, the need for testing expands,” he said. “You have to test those who have come in contact with the affected person.”

Every confirmed case of coronavirus means many more people who came in contact with them getting tested.

While this explains why states with the highest number of coronavirus cases are also reporting the highest number of tests, experts say India’s restrictive testing policy is risky.

So far, coronavirus tests in India have been limited to those who have recently travelled to coronavirus-affected countries or those who have come in contact with them and have symptoms of the disease.

Health experts say limiting tests to those with travel or contact history could result in the country failing to detect cases of community transmission. In such cases, the source of infection cannot be traced to a known confirmed case.

On Friday, the Indian Council of Medical Research said it would test 1,000 random samples of influenza-like illnesses and severe acute respiratory infections every week to check for community transmission of coronavirus.

Nivedita Gupta, scientist at the ICMR’s epidemiology and communicable diseases division, told Scroll.in on Sunday that such testing has already begun.

In the first phase, samples collected between February 15 and February 29 were tested. All were found negative.

“At that time, we had 13 such labs doing 20 samples each,” she said. Since then, the network has expanded to 51 labs. “We have now asked them to test 20 samples per lab collected between March 1 and March 15. These results will come out by Tuesday,” she said.

This means, by Tuesday, the ICMR would have a clear idea of whether community transmission of coronavirus has taken place in the country.

Given this context, are states like Tamil Nadu doing enough? Excerpts from the interview with Tamil Nadu public health director K Kolandaswamy.

Source: Indian Council of Medical Research.

How many samples has Tamil Nadu tested for coronavirus?
As of Sunday, we have collected 88 samples. Of these, 85 turned out to be negative and one was positive. That patient has been isolated and being treated. Two samples are in the process of being tested. Since the infection may remain asymptomatic in the initial days even if the tests turn negative, we have 15 people who fulfilled the guideline criteria in isolation at hospitals.

Has Tamil Nadu started testing for community transmission?
As per ICMR instructions, we tested 22 random samples of people with influenza and severe acute respiratory infection for coronavirus. These samples were from February. All were negative. We are doing second batch for March now.

We also test coronavirus suspected samples for a panel of infections, such as swine flu. This helps us understand what is happening in the community. If not coronavirus, what is it? This is actually a standard procedure adopted when there is outbreak of any infectious disease. For example, when there is a dengue outbreak, we test samples we get for other infections also. The benefit of testing for a panel of infections is that it gives you a better picture of what the ground situation is.

There are lot of accusations that Tamil Nadu is not testing even those with symptoms and travel history and that these people are being sent back by government hospitals without collecting their samples.
There is a problem we are facing because people are just assuming that once they get a cough or cold, the government should test them. We have clear guidelines in place for testing. The protocol is currently this: when a person calls the helpline numbers, we gather information about their history. We then send an ambulance to their place to pick them up to the hospital. We also allow them to use private transport like a car if they possess one and tell them how to disinfect if necessary. At the hospital, doctors will decide, as per the case history, if testing is warranted or not. This includes symptoms, travel history and epidemiological linkage, that is coming in contact with already affected persons.

We have seen a lot of cases over the last few days when people just come into the hospital and say test us. There have also been cases where they come and ask that they need a certificate that they are negative for coronavirus as this is necessary for travel. This is not possible given the burden of cases the country is expecting. They also say test us and if we have it we will deal with it. Which means they won’t accept quarantine. But I can assure you that no one who fulfills the protocol is being let off without being tested.

Then why have we seen only one case in Tamil Nadu? When surrounding states report higher numbers, this raises questions on the efficiency of Tamil Nadu’s testing procedures.
You need to understand that all these states are not alike. For example, take Kerala. The volume of travel to West Asia and Europe is likely to be higher there. Hence, you are seeing more cases. And if you see, all these cases have contact history. When you have more positive cases, the need for testing expands. You have to test those who have come in contact with the affected person.

What is the capacity of the four labs in Tamil Nadu?
We can test any number as and when it is necessary. At the moment, we are getting the primer necessary for the testing from the National Institute of Virology, Pune. If the testing burden increases, the labs will be trained to make the primer on their own and test after fulfilling the controls mandated. All four labs in the state are now functional. The fourth lab we got in Tirunelveli has already tested two samples.