The variation in testing figures over the past few days has become a subject of debate in the State. But Health Minister C. Vijayabaskar has said that except for exit tests, Tamil Nadu has in no way limited or reduced the number of samples being lifted for testing, and is now testing all persons arriving in the State by flight, train and road.

The number of samples being tested per day has been fluctuating between 10,000 and 14,000 over the past two weeks. It stayed above the 13,000-mark for a few days earlier this month, and decreased to 10,535 on May 16. A day later, the figure went up to 13,081. On May 18, it stood at 11,121.

“There is no drastic decline in the number of samples in the graph. Our testing numbers have not gone below 10,000. T.N. has tested over three lakh samples. On an average, the number of samples tested is in the range of 4,000 to 8,000 in many districts. In Chennai, we have tested about 85,000 samples,” he said.

During a media briefing on Monday, the Minister said that an analysis of the testing graph showed that the 10-day average was 12,536.

He maintained that the State was carrying out tests in accordance with the guidelines issued by the Indian Council of Medical Research. “Earlier, it was persons with a travel history and symptoms, and contact history and symptoms [who were subjected to testing]. The strategy was subsequently changed. Earlier, we were testing the persons living on a street where a positive case had been reported, and non-home contacts. Now, we are testing all those with influenza-like illness across the State, thereby covering even persons with the mildest symptoms of cough and fever. Those with severe acute respiratory infection are being tested,” he said.

In containment zones, asymptomatic patients and their primary contacts were being tested and, based on suspicion, secondary contacts as well. “We are now testing all persons arriving here on flights from abroad and trains. Those entering the State by road are being screened at checkposts. We are getting a cluster of cases from among those returning from Maharashtra,” the Minister said.

No need for exit tests

As per the Central government’s guidelines, there was no need for conducting exit tests, i.e., testing of COVID-19 patients before discharge. Earlier, the norm was that two samples should return negative in order for a person to be discharged. “However, we continue to test them. We are lifting one sample before a patient is discharged,” he said.

The number of samples lifted peaked every time a cluster emerged or a large group of persons were tested, he said, adding, “The testing numbers peaked when cases linked to the Koyambedu market emerged. It is over now. Similarly, the number of samples peaked when frontline workers, including police personnel, and mediapersons were tested in large batches,” the Minister said.

It was important to understand that these were RT-PCR tests and not an instant testing methodology, he said, adding, “It takes six hours to complete the process. People are working in three shifts throughout the day. If we were reducing the number of samples being lifted, we would have cut the number of testing facilities. Instead, we have 61 laboratories now.”