Eight Covid positive samples in RAD test negative on RT PCR in Bihar’s Madhubani

The district authorities had sent 25 swab samples for confirmatory RT-PCR tests to the Madhubani Medical College on Monday and Tuesday, after 76 samples had tested Covid-19 positive in the RAD tests, conducted among passengers at the Madhubani railway station over the last four days, raising alarm among district health officials.

Madhubani’s district authorities heaved a sigh of relief after eight of the 25 swab samples, positive on the rapid antigen detection (RAD) kits, tested negative on the real-time polymerase chain reaction (RT-PCR), a confirmatory test for Covid-19 Tuesday evening, said health officials.

A health worker collects swab sample of a woman for Covid testing in Patna. (HT File)

Results of 17 samples are awaited.

The district authorities had sent 25 swab samples for confirmatory RT-PCR tests to the Madhubani Medical College on Monday and Tuesday, after 76 samples had tested Covid-19 positive in the RAD tests, conducted among passengers at the Madhubani railway station over the last four days, raising alarm among district health officials.

As many as 22 passengers of the 76 found positive on RAD kit since September 17 were not traceable, said officials. Most had come by train from New Delhi and Mumbai.

“Some have given us incorrect mobile number and address. While some mobile numbers belong to people of other districts, most others are either unreachable or switched off. This has made it difficult for us to locate them,” said health officials.

The district authorities had reasons to believe that the RAD kit results were false positive after around 12 passengers tested negative during a re-test on the RAD kit at their village in Babu Barhi, Harlakhi, Raj Nagar, Madhepur and Benipatti, said an official.

“The sensitivity of RAD kit depends on many factors, the temperature being one. We are getting all the samples re-checked on RT-PCR,” said Dr Sunil Kumar Jha, Madhubani’s civil surgeon.

The Bihar Medical Services Infrastructure Corporation Limited, which purchased the RAD kits, has been asked to check them.

“The sudden rise in cases, the asymptomatic nature of patients, epidemiological references that false-positive cases go up when the prevalence of a disease goes down, some passengers testing negative during a re-check on RAD kit at their village, as also the fact that no other passenger at any railway station earlier en route Madhubani from New Delhi or Mumbai reported positive, had raised suspicion that these may be false-positive cases,” said Dr Jha.

The district has been testing average daily 1600-1800 samples, the results of which were negative for the past few days, said Madhubani civil surgeon.

Meanwhile, the district authorities have allowed all Covid-19 suspects to be under home isolation till the results of RT-PCR tests allow for some conclusion on their status.

“Our healthcare workers are checking on them on a daily basis to see if their condition deteriorates. We are also pressing on them to opt for institutional isolation. Around 800 beds at Covid care centres, available in our district, are vacant,” added Dr Jha.

The Covid-19 bulletin, released by the health department on Monday, reported only seven new cases in the state. Of them, two were from Gopalganj and one each from Patna, Madhubani, Bhojpur, Purnia and Katihar. Madhubani reported only 14 active cases out of the total 18,359 cases and 338 deaths there so far.

Bihar has reported 725,901 cases and 9,659 deaths since March 21, 2020, when the first Covid-19 case was reported in the state. Patna, with 146,942 cases and 2,334 deaths, was the worst affected. As many as 716,173 patients have recovered so far, adding to the state’s case recovery rate of 98.65%. The number of active cases in the state has come down to 68

.