Rapid testing on hold, govt plans to scale up PCR tests
The move comes even as efforts to boost testing using rapid testing kits (RTKs) that do antibody tests have flounderedUpdated: Apr 23, 2020 00:54 IST
New Delhi: India is working on testing up to 50,000 people a day by the end of the month -- using the Reverse Transcription Polymerase Chain Reaction or RT-PCR test -- as the country approaches the May 3 deadline for the end of the ongoing lockdown, resulting in a potential increase in infections.
The move comes even as efforts to boost testing using rapid testing kits (RTKs) that do antibody tests have floundered. Experts have always warned that these aren’t good at early diagnosis and better used to track an infection’s spread in a population; the initial RTKs imported by India have also given readings with wide variations. causing the Indian Council of Medical Research (ICMR) to suspend on Tuesday their use for two days.
Meanwhile, the ministry of health has equipped labs, acquired testing kits, and trained staff to work on two shifts to scale up Covid-19 testing using RT-PCR, the gold standard of tests for the disease.
RT-PCR is used for qualitative detection of genetic material called nucleic acid (RNA) from Sars-CoV-2, the virus that causes Covid-19, and is the most accurate diagnostic test for infection. “Rapid antibody tests are surveillance tools, they are not tools for disease positivity. For diagnosis of Covid-19, we need RT-PCR, and a planned scale-up is happening. The Indian Council of Medical Research has approved 304 public and private labs to test for Covid-19 across states, and on Friday, we expect to cross 500,000 cumulative tests,” said CK Mishra, secretary, ministry of environment, and co-chair of the PM’s high-level committee on preparedness for medical emergency.
“There is no shortage of machines, and reagents including RNA extraction kits and composite kits, and orders have been placed with domestic and international suppliers in anticipation of testing being increased over the coming weeks,” said Mishra.
India has ordered 12 RT-PCR systems that can test up to 1,000 samples each in a single run, of which six are expected to be delivered in early May. These will add to two such machines in ICMR labs in Bhubhaneshwar and Noida.
As of April 21, the Central Drugs Standard Control Organisation (CDSCO) has approved 47 companies to manufacture and import PCR kits, of which four are indigenously developed and manufactured; 16 are from China; and the rest are from other parts of Asia, Europe, and the US.
The government has at least 300,000 RNA extraction kits in stock, along with an equal number of composite kits. The distribution of essential diagnostics supplies has also been decentralised to 15 depots across the country to ensure uninterrupted supply and prevent transfer delays.
The Pune-based Mylab, which was the first Indian company to get an indigenously developed test approved by ICMR, plans to double its output over the next 10 days. “Since we got the CDSCO nod on March 23, we have dispatched three lakh tests and will increase this number to seven lakh by the time the lockdown lifts,” said Hasmukh Rawal, managing director, Mylab.
Sachin Gulati, who is a partner at the Delhi-based Solutions One, imports CE- and ICMR-approved PCR kits from the Seegene in South Korea. “There’s no shortage, I have a revolving stock, and have 800-900 kits on demand, with each one testing 100 samples. More are on the way, and we supply to both government and private hospitals and labs,” said Gulati.
But overlooked ancillary products needed for testing are threatening to play spoilsport. .
“The machines and kits are available and we have several vendors to choose from, but ancillary products like swabs and viral transport media, which is needed to transfer swab samples to the lab, are in short supply. Getting these basics right is important, as we need nylon, dacron or flexon swabs for sensitivity; cotton ones can contaminate the sample and influence results,” said Dr Navin Dang, consultant microbiologist and founder of Dr Dangs Labs, which was among the first labs to get approved for Covid-19 testing in India.
“Getting trained technicians is also proving to be a challenge in the private sector,” added Dr Dang. “Government labs have trained staff on call, but for us [in the private sector], adding staff is a big problem also because of the fear and stigma associated with Covid-19.”
To increase diagnostic reach, ICMR has approved machines used to test drug-resistant tuberculosis for Covid-19 tests, with the Prime Minister’s empowered group identifying as many as 250 Gene-Xpert cartridge-based nucleic acid amplification test (CBNAAT) and 150 Truenat machines.
Truenat is a small battery-operated machine that can run 32 to 48 samples. It takes just up to 60 minutes from swab to confirmation and can be operated by health workers with basic training even at the Primary Health Centre, while CBNAAT are widely available across India. CDSCO has approved indigenous Truenat beta-CoV test as a screening test.
“These machines give results in an hour, don’t need a sophisticated lab, and people trained to use them are there at the grassroots level, which will help deliver testing to underserved areas,” said a health ministry official, who did not want to be named.