Same day, same Covid-19 test, two different results!

Same day, same RT-PCR test, two different results. One says that the person is positive for Covid-19, while the other says negative.

Tarek Ahmed, 44, tested positive for Covid-19 on July 1.

"I waited for 14 days for the illness to subside, and tested again. First I went to Bangabandhu Sheikh Mujib Medical University [BSMMU] and have a test done. Then, on the same day, I went to a Brac booth that collects samples to be tested by Institute of Epidemiology Disease Control And Research and gave my sample again," described Tarek.

BSMMU test results said he was negative for the virus, but IEDCR said he was positive.

Tarek had no symptoms on the day he gave samples.

When asked why he tested at two sites, Tarek said it was sought by his workplace -- a petroleum company.

Experts have long mused about the incidence of false positives or false negatives when it comes to RT-PCR tests.

"The limitation of RT-PCR is that the sensitivity depends on the sample collection, the kind of sample, the kind of media being used for testing," Dr M Shawkat Hassan, director of the department of laboratory medicine at Birdem hospital said at a webinar organised by Bangladesh Health Watch earlier this month.

Meanwhile Dr Bijon Kumar Sil, head of the microbiology department at Gono Bishwabidyalay, had previously told The Daily Star that when people were recovering from Covid-19, their test results may come out positive because the PCR machine detects the dead viral RNA in their sample.