Gonoshasthaya Test Kit: Sample error leads to false negatives

Gonoshasthaya Kendra has asked the Bangabandhu Sheikh Mujib Medical University to suspend the performance trial of the coronavirus antigen kit after detection of discrepancy in the collection of saliva.

"The monitoring team for the performance trial identified that the presence of thick cough causes negative results in a number of samples. So, we have sought temporary suspension of the trial," said Dr Mohib Ullah Khondoker, coordinator of Gonoshasthaya's Covid-19 Rapid Dot Blot Project.

He told The Daily Star that clear saliva is necessary for testing antigen, but the monitoring team that is comprised of scientists of BSMMU and Gonoshasthaya Kendra identified the problem in the sample collection procedure.

"We have written to the BSMMU authorities on June 2 that we will fix the sample collection procedure in two to three days and then they can restart the trial again," Mohib Ullah told The Daily Star yesterday.

Gonoshasthaya Kendra has, meanwhile, sought speedy completion of the trial of antibody test kit and submission of the report to the Directorate General of Drug Administration so that the latter can authorise mass production and marketing of the antibody test kit.

A team of Gonoshasthaya Kendra scientists developed the antibody and antigen kits to test for Covid-19 in mid-March. On April 26, they approached the DGDA for validation of the kit.

The drug administration, however, suggested that Gonoshasthaya Kendra go through a contract research organisation (CRO), but Gonoshasthaya refused to do so, saying that it would raise prices of the kit and that CROs were a vehicle of corruption.

On April 30, the DGDA allowed Gonoshasthaya Kendra to go through performance trials at BSMMU. Gonoshasthaya supplied 500 antibody and 500 antigen kits to the BSMMU for the trials.

Gonoshasthaya Kendra Founder and Trustee Dr Zafrullah Chowdhury has repeatedly demanded that the authorities go for emergency authorisation of the antibody kits as the infection rate is increasing every day.

The antibody kit, which is low-cost and can give result in 10 minutes, could be used for large-scale testing and isolation of the infected people -- a way that could prevent the spread of the virus, he said recently.

In its own trial, Gonoshasthaya found the tests to be more than 90 percent accuracy. The test kit -- RT-PCR -- that is now being used in Bangladesh is considered the gold standard, but that is time-consuming and expensive.