Gonoshasthaya claims kit achieved 97.7% sensitivity, 96% specificity in internal trials
Gonoshasthaya Kendra(GK) will take another shot at external validation of their Covid-19 antibody test kit, GK scientist Dr Bijon Kumar Sil said on Sunday.
He also said the kit achieved 97.7% sensitivity and 96% specificity in internal validation, which is higher than what is required under the guidelines of the US Food and Drug Administration (FDA).
Dr Bijon made the observations after a meeting with the Directorate General of Drug Administration (DGDA).
“On June 24, Bangladesh adopted a guideline on antibody test kits following that of the US FDA. We have developed the kit as per these guidelines and it achieved 97.7% sensitivity and 96% specificity,” he said.
“The guideline requires 90% sensitivity and 95% passivity, so our test is more accurate than needed. We will submit the internal report to the DGDA and the kit will go for external validation again,” he added.
Md Salah Uddin, deputy director of DGDA, told Dhaka Tribune that the DGDA is always ready to provide technical support.
“The GK kit failed an external validation conducted earlier. If GK can arrange the process again and their kit passes external validation, that will be fine. We told them they can conduct internal tests and validate by a third party again,” he said.
In the previous external validation, conducted by Bangabandhu Sheikh Mujib Medical University Hospital (BSMMU), the GK kit achieved only 70% sensitivity. However, another GK scientist and co-inventor of the kit, Dr Firoze Ahmed, claims the kit only failed because the validation was not conducted properly.
After Sunday’s meeting with the DGDA, Dr Firoze said: “According to the recently adopted guidelines, external validation should be done by using the kit on people who have already developed antibodies as confirmed by another kit, but BSMMU did not do that. They did not confirm antibodies in the respondents’ bodies before the external validation, so the sensitivity came out to only 70%.”
What is sensitivity and specificity?
The accuracy of antibody test kits is usually presented through two numbers: sensitivity and specificity.
Sensitivity refers to the accuracy of the kit in detecting positive cases, which means a high sensitivity results in few false positives.
On the other hand, specificity refers to the accuracy of the kit in detecting negative cases where a high specificity results in fewer false negatives.
GK working on rapid test kit
A team of GK scientists also went to the DGDA to discuss their antigen (rapid) test kit for detecting patients. The GK team were provided with a draft copy of the DGDA’s upcoming guidelines on antigen test kits.
“The DGDA is still preparing the guidelines for antigen test kits. They have provided us with a draft copy of the guidelines and we will develop the rapid test kit following them,” Dr Firoze said.