POSITIVELY VICIOUS The novel coronavirus is surrounded by 29 crown-like spike proteins that attach themselves to human cells and infect them. To detect its presence, the RNA in a sample has to be first converted into DNA, then amplified to help sequester

India has two kinds of tests in its arsenal to combat COVID-19: the confirmatory RT-PCR test and the indicative rapid antibody test. Here is what both entail

been greenlighted by the empowered committee set up on March 29 under Dr V.K. Paul, member, NITI Aayog. “Rapid tests will help gauge the extent of the spread and make it quicker to isolate potential cases,” says Dr Paul.

To prepare for the widespread testing, ICMR has granted licences to 51 companies to sell rapid test kits and another 33 firms to sell PCR test kits in India. The body has also floated a tender to acquire 5.3 million kits for the transport of viral samples, 2.5 million PCR test kits and 4.5 million rapid test kits.

But Is It Enough?

For sure, the country has come a long way since ‘patient zero’ tested positive in Kerala on January 30. Between then and March 27, only 27,686 samples had been tested, of which 834 were positive. Ten days from then, the number of samples tested went up to 73,380, and the number of cases rose to 3,955. As many as 11,432 samples were tested on April 6 alone, of which 311 were confirmed cases. But testing still varies widely between states. So, while West Bengal with 99 million people has conducted only 38 tests per million, Kerala, with 34 million people, tested 497, as on April 16.

A primary reason for slow testing in India is the unavailability of test kits. In early February, the National Institute of Virology in Pune had procured 1 million reagents (chemicals that convert RNA in the virus to DNA) and 1 million primers and probes (which amplify DNA and then detect the genetic sequence specific to COVID-19) for PCR tests. Though Gangakhedkar insists India has enough test kits for the next six weeks, there is no available official count on the current stock with

ICMR. The 500,000 rapid kits ordered earlier departed from China only on April 16, almost a month late. “There is a global shortage in rapid kits, as almost all countries are looking to introduce it,” says Malini Aisola, co-convenor of advocacy group All India Drugs Action Network. “Till we have enough quality equipment for testing, you cannot ramp it up.”

Not just rapid kits, PCR kits too are in short supply. While rapid kit manufacturers are yet to be cleared in India, the empowered committee is trying to give domestic manufacturing a push for PCR kits. Three labs—NIV and the National AIDS Research Institute (NARI) in Pune, and the National Institute of Pathology in New Delhi—evaluated nonFDA or non-European CE-certified commercial kits. On March 23, MyLabs in Pune became the first to get ICMR approval to sell its COVID-19 kit. Though the company, in existence since 2016, claims to be ‘FDA approved’ on its website, its products do not have FDA approval. MyLabs CEO Hashmukh Rawal clarifies: “We spent the last six years working to develop our ID NAT kit, which detects HIV molecules in blood samples. We have received CDSCO (Central Drugs Standard Control Organisation) clearance for this, equivalent to an FDA clearance in India.” The kit, priced at Rs 800, was designed in six weeks by Minal Bhosale, R&D head at MyLabs, who had earlier worked with NIV Pune during the 2009 swine flu outbreak.

On April 2, Bhopal-based Kilpest India became the second Indian company to receive clearance for its kit. The company had earlier been rejected after its kit’s true positive correlation scored 75 per cent, even as the true negative

correlation was 100 per cent. “After the first attempt, we added one more targeted gene and played around with the internal chemistry a bit,” says Dhirendra Kuber Dubey, director of the company.

Together, the two companies claim they can manufacture 8.3 million kits per month. Adar Poonawalla, whose Serum Institute has partnered with MyLabs, says, “Our production capacity is 1.5 lakh units a week, we will soon scale it up to 20 lakh a week.” Asked how many kits his company has delivered so far to the government, Rawal vaguely offers: “We have delivered thousands across the country to state departments and private labs.”

Then, there is the question of the validity and reliability of the tests themselves. Of the 51 firms the government has cleared for rapid kits, seven are Chinese. Of these, two—Wangfo and All Test—are the ones from which the UK too has ordered about a million kits. On April 6, Professor John Bell, coordinator of coronavirus testing for government agency Public Health England, announced that the tests had “not performed well” when being evaluated and that they had a high number of false positives and negatives. Spain, too, allegedly withdrew 58,000 kits made by Chinese firm Shenzen Bioeasy Biotechnology as they were not accurate, though India is not importing from them.

The RTPCR test itself is the gold standard in testing, asserts biotechnologist and gene specialist Virander S. Chauhan. “Unless the samples or chemicals are contaminated,” he says, “it gives an extremely accurate picture of whether a sample has a virus or not; it is, after all, hunting for a gene specific to COVID19.” But a lot also depends on the design of the kit, the genes it targets and how samples are collected and tested. As per ICMR’s own declaration, neither Kilpest nor MyLabs was tested as per its guidelines for sensitivity or specificity as no false positive or false negative samples were taken. False negative and positive determinations for kits are a step requisite for both FDA and European CE approvals. “We are ensuring every test has a 100 per cent true negative and a 100 per cent true positive,” says Dr Gangakhedkar. There are methods by which repeatedly testing a kit could ascertain its sensitivity and specific

ity, but ICMR is yet to make public its protocol for testing kits before approval, in the absence of which it is impossible to judge the reliability of the kits being cleared for sale. “We would have a clearer picture of whether false negative or positive samples are needed for kits if we knew how the tests for sensitivity and specificity were being conducted,” says Aisola. A false positive can mean isolation for a person, but a false negative for an infected person will mean no treatment or isolation—undesirable for a disease as infectious as COVID19. ICMR declined to comment on either the protocol for kit clearance or why manufacturers are not being provided human controls. (A positive control is a sample of the COVID19 RNA, which can be extracted either from a human sample or a synthetic one.)

The reliability of RTPCR tests also depends heavily on lab infrastructure, trained lab technicians and the availability of PPE, or personal protection equipment, to prevent sample contamination. India still has only 219 testing facilities for 720 districts, which means samples have to be packed and transported, delaying results. Various state governments have requested ICMR to clear 45 labs, but only eight had been cleared till April 13. Dr Pradip Kundu of the School of Tropical Medicine, an ICMRapproved testing centre in Kolkata, says they have an extreme shortage of PPE and trained personnel. “We have one virologist and three microbiologists, but we need expert technicians and an automated RNA extraction machine,” he says.

What is also needed is communication about testing. “Public outreach is the foundation of a good public health strategy,” says Chapal Mehra, a public health analyst in Delhi. “People need to know basics—the kinds of tests, their reliability and cost, who should be tested and at what stage.” Communication, after all, played a huge role in Kerala’s success in dealing with the disease. Field workers made door to door calls to tackle any fear of being tested. “No disease can be stopped without people’s participation,” says Dr Amar Fettle, the nodal officer for infectious diseases in the state health department. “The public will step up when they know what to do. So we made it extremely clear that if you have symptoms, go to a quick centre for a PCR test. If you don’t have symptoms but have been in contact with someone who does, consult a doctor and get a PCR test. We ensured everybody knew this, from schoolchildren to the elderly.”

There is now an effort to disseminate information via social media, radio and television, but confusion remains. Many do not know the difference between rapid and RTPCR tests, and do not realise that the rapid test is not a confirmatory test for COVID19. Bengalurubased startup Bione has been selling singleuse rapid kits for Rs 2,500, claiming in their description that they can provide results in 510 minutes. On April 5, CDSCO released a public notice saying the company did not have a licence to sell in India and was not on the list of ICMRverified rapid kits.

India has bought itself some more time by extending the lockdown, but has yet to get its act together. The government has placed orders for PPE, announced plans to enlist ENT specialists to collect samples and to expand testing centres to include medical colleges. Testing, however, has still not been ramped up to desired levels. Lockdowns, after all, can only be temporary reprieves.