With India crossing 35,000 covid positive cases, the biggest one day jump, it becomes very important to conduct regular tests to be able to control the spread of the deadly virus by identifying the carrier and putting them into quarantine or isolation. But, it seems like rapid and mass testing has started to take a toll on India’s testing labs and is creating a bottleneck.  


The number of pending swab samples seems to be the worst in Delhi as the samples pending for tests in Delhi goes up by seven times in one month from 470 on April 1 to 3,295 as on April 29. Delhi has twenty labs, eight government-run and twelve private labs, that are approved for Covid-19 testing, the highest for any city in the country. 

Some of the swab samples from the state are also sent to the National Institute of Biologicals (NIB) in Noida, which has an automated machine that undertakes 1,000 tests a day and has a faster turnaround time.  


The major problem is that NIB, where the majority of the city samples were being sent over the past 15 days, hasn’t released reports expeditiously. Secondly, Of the eight government labs in Delhi, five are run by centre and one of them is run by the Army Research and Referral hospital. 

Some of them, for example the lab run by the National Centre for Disease Control (NCDC) and AIIMS, get swab samples from states like UP, Rajasthan and Jammu & Kashmir as well. Only two labs run by Delhi government, one at Institute of Liver and Biliary Sciences (ILBS) and another one at Maulana Azad Medical College (MAMC), are approved for Covid-19 testing. 


Sources said their combined capacity for daily testing is less than 500 which isn’t sufficient to meet the increased demand.  

It’s not just Delhi which is facing the testing crisis, a similar situation is happening in Karnataka as well. Around 5,000 swab samples are pending at the 17 laboratories in Karnataka, as reported by The Economic Times. 


The backlog increased during last week as districts started sending more samples, including those of primary and secondary contacts and patients with severe acute respiratory illness (SARI) and influenza like illness (ILI). 

As on April 18, the number of samples received was 24,424 and those tested was 19,186. In Karnataka, 17 laboratories are now testing about 2,000 samples a day, but the backlog hasn’t come down as the state has been sending more samples since April 15.  


The National Institute of Virology (NIV) lab in Bengaluru has taken the highest load, testing 4,299 samples so far, followed by Bangalore Medical College (BMC) that has tested 3,250 samples. Regional labs are yet to take the load.

For instance, the laboratory in one of the Covid-19 hotspots, Kalaburgi, was made operational a month ago. Despite having a capacity to test 80-100 samples a day, the lab has tested only 848 samples so far. The lab in Mysore with a capacity to test 200-250 samples per day has tested only 1,682 samples in 40 days since it became operational.  


Similar backlogs were reported in Madhya Pradesh, West Bengal, Rajasthan and Gujarat. To cope, Rajasthan last week sent 4,000 swab samples to Delhi. Madhya Pradesh has sent over 1,000 samples to Puducherry. Delhi, Rajasthan, Madhya Pradesh, and Gujarat are among the worst-hit states in India, after Maharashtra. 


Health officials say the backlog is due to the specific requirements of RT-PCR tests from equipment to logistics. An RT-PCR test detects the genetic material of the virus and requires technicians with specific know-how. 

Worse, the simpler rapid antibody test that could have aided in India’s surveillance, and thus potentially covering up for the backlog on RT-PCR, has been suspended over faulty kits sourced from China.