Over 73.5 lakh samples have been tested for COVID-19, of which 2.15 lakh were done on Tuesday, the highest in a day since the beginning of the pandemic, Indian Council of Medical Research officials said on Wednesday.
The apex health research body on Tuesday validated the 1,000th testing laboratory, ramping up the capacity for detection of COVID-19 in the country.
Currently, three lakh samples can be tested per day, an official said.
"A cumulative total of 73,52,911 samples have been tested up to June 23, with 2,15,195 samples being tested on Tuesday," the apex health research body said.
Of the 2,15,195 tests conducted on Tuesday, 1,71,587 were done in government laboratories and 43,608 in private ones, the Union health ministry said, adding the private facilities have also reached the highest per-day sampling with this quantity.
Of the 1,000 COVID-19 testing laboratories, 730 are in government setups while 270 are in the private sector. This includes 557 RT-PCR labs, 363 TrueNat Labs and 80 CBNAAT Lab.
'However, in spite of these developments, access to testing still remains a huge challenge in a large country like India. There is a definite need to increase the outreach of testing by introducing rapid point of care diagnostic tests,' the ICMR noted in its advisory issued on Tuesday.
Also, sero survey with IgG-based antibody tests can be conducted in certain situations, officials said.
It is now suggested to include additional testing methods to improve access and availability of testing in various parts of the country, the health research body said.
The real-time RT-PCR is the gold standard test for detecting cases of COVID-19 and the average time between receipt of sample and getting the result is around four to five hours.
'The advantage of this platform lies in its accuracy of detection as well as ability to run up to 90 samples in a single run. In view of the requirement of a specialised laboratory setup, this test cannot be performed at every district-level lab which does not have molecular virology facilities,' the ICMR said.
The TrueNat and the CBNAAT systems have also been deployed for diagnosis of COVID-19 in view of availability of customised cartridges.
These platforms have widespread availability even at district and primary health centre-levels as these are widely used for diagnosis of tuberculosis and other infectious diseases.
These platforms have a quick turnaround time (30-60 minutes) but only one-four samples can be tested in one run, limiting the maximum number that can be tested to 24-48 samples per day only, the ICMR said.
The ICMR recently also approved the use of rapid-antigen test for coronavirus infection that gives results in 30 minutes.
It has recommended deployment of rapid antigen detection test for COVID-19 in combination with the RT-PCR test in all containment zones, central and state government medical colleges and government hospitals, private hospitals approved by the National Accreditation Board for Hospitals and Healthcare (NABH), and all NABL-accredited and ICMR-approved private labs for COVID-19 testing.
The apex health research body has also advised that the rapid antibody test for COVID-19 should be performed only for surveillance purposes, and not diagnosis, to help allay fears and anxiety of healthcare workers and employees.
IgG antibodies generally start appearing after two weeks of onset of the infection once the individual has recovered, and these last for several months.
It can be used to conduct serosurvey to understand the proportion of the population exposed to infection with SARS-CoV-2, including asymptomatic individuals, and to carry out survey in high-risk or vulnerable populations (healthcare workers, frontline workers, immunocompromised individuals, individuals in containment zones etc) to know who had been infected in the past and has now recovered.
