When all 10,000 people tested negative for the coronavirus amid a raging pandemic, health officials in Uttar Pradesh’s Bareilly district smelt a RAT.

Sources in the district health department said that thousands of Covid rapid antigen test (RAT) kits sent from the state headquarters in Lucknow had turned out to be faulty.

According to the sources, when experts had pointed out that all results were coming out negative, seniors in the district health department had insisted that they continue testing with the same kits. When finally RT-PCR tests were conducted on people suspected to be infected from among the 10,000 tested earlier with the RAT kits, 700 were found to be infected over two days, the sources said.

Rapid antigen tests are anyway not considered reliable as they frequently throw up false negatives, but they are used because they give quick results. RT-PCR tests are considered the gold standard in Covid detection.

The sources in the Bareilly health department said the RAT kits had been supplied to community health centres and medical mobile units from the state headquarters in Lucknow last month.

“As we began using the kits, the experts suspected that they were not giving correct results. All the test

reports were coming out negative even if the swab samples had been collected from people with high fever, cough and other symptoms of Covid,” a health department official said on the condition of anonymity.

“We informed our seniors about the problem in April-end but they asked us to continue testing with the same kits. Eventually all 10,000 people we had tested turned out to be negative,” the official added.

He said that finally on May 3, teams in Bareilly were asked to visit the houses of people who had turned up with symptoms for the antigen tests and conduct RT-PCR tests.

“We had suspected that at least 10 per cent of those who had undergone the antigen tests were infected. We have now begun getting the results of the RT-PCR tests. We got 300 positive reports on Tuesday and 400 on Wednesday,” the official said.

“These people have now been asked to quarantine themselves. All this while they had been mixing with others at home and probably outside, thinking that they were Covid-negative. We fear the infection has now spread among many others,” he added.

The health authorities in Bareilly conceded that the RAT kits were faulty.

Ranjan Gautam, the assistant chief medical officer of Bareilly, said: “There is lack of clarity on the antigen test reports. We have ordered the remaining kits to be replaced as we had received complaints about them. The faulty kits have been returned to the headquarters. Those whose RT-PCR samples have been collected in the past few days have been asked to stay in home isolation.”