The district health department on Tuesday distanced itself from data published by a private laboratory, which claimed that 16 to 20 percent of all samples tested from three neighbourhoods in Gurugram showed presence of antibodies for SARS-Cov-2. Officials, including the district chief medical officer (CMO), said that the private laboratory in question has not been authorised to carry out any seroprevalence studies in Haryana (or Gurugram), and that the data itself ‘did not have a scientific basis’.
Arokiaswamy Velumani, founder and managing director of Thyrocare Technologies Limited — a chain of diagnostic laboratories based in Navi Mumbai — had published the survey data via his Twitter handle on July 17. In his tweet, Velumani said that for every Covid-19 related death in India, 10,000 people have been “silently immunised”, based on test results of 53,000 samples collected from 87 pin codes across India (including Gurugram).
While nationally, Thyrocare’s data claims an average 15 percent seropositivity rate, the figures in Gurugram ranged from 16.8 percent (in Narsinghpur), to 18.4 percent (in Chakkarpur) and 20.8 percent (in Arjun Nagar) — all areas which have been classified by the district administration as ‘hotspots’. Health department officials, however, remained sceptical about these numbers.
Dr Virender Yadav, chief medical officer of Gurugram, said, “We cannot comment on the accuracy of the data. We do not know what sample size or design the lab has used in Gurugram, and we have not given permission to Thyrocare to carry out such kind of testing. There is a major ethical oversight in publishing data from commercial tests as part of a clinical study. If any private entity wants to carry out such an exercise, let them take permission and follow ICMR guidelines for sero-surveillance. We will refer this matter to the state government who will take further action, if necessary.”
Velumani, however, has clarified that Thyrocare’s data is based largely on commercial tests. “About 85 percent of the tests carried out were done commercially, for corporate clients. It is not part of any study or clinical trial. The tests have all been carried out at our laboratory in Mumbai, which is accredited by ICMR and NABL. The samples are transported through an established cold chain system to maintain the integrity ,” Velumani said.
Dr Jai Prakash Sharma, the Integrated Disease Surveillance Program’s district surveillance officer in Gurugram, said that the state health department is in the process of carrying out its own sero-prevalence study, in keeping with the ICMR’s guidelines. “Given that Thyrocare’s sample only consists of paying clients, the results would naturally be skewed. The sample population for sero-prevalence studies need to be carefully calibrated,” Sharma said.
As of July 21, the state health department has tested 1,544 people as part of its ongoing sero-survey, which found that 11 percent had developed antibodies against the virus. The largest proportion of sero-positive diagnoses have been attributed to Sonepat, where 60 of 350 blood samples collected were sero-positive. The maximum number of antibody tests — 454 total — were done in Gurugram, out of which 56 were confirmed positive to have Covid-19 antibodies. Likewise, in Faridabad, 209 tests were conducted with 28 people testing positive. In Ambala, 176 people were covered under the survey, out of which 27 were found to be positive. Panchkula reported the least number of positive cases. Out of 355 tests conducted, nine were found to be positive for Covid-19 antibodies there.
A senior epidemiologist based in Gurugram, however, was reluctant to dismiss Thyrocare’s data entirely. “The ethical considerations is for the government to comment on. As far as epidemiological value is concerned, it may be worth the health department’s time to look into what the data indicates. Narsinghpur, Chakkarpur and Arjun Nagar are densely populated areas that have reported a disproportionately high number of cases. Sero-prevalence of 16 to 20 percent in this areas is not implausible, if the sample size was big enough,” said the epidemiologist, who did not wish to be quoted as they had not seen Thyrocare’s raw data.
Malini Aisola, co-convener of the All India Drug Action Network said, “ICMR has clarified that the utility of antibody testing at this stage is limited to sero surveillance. Can Thyrocare explain what permissions it had for the sero-surveys and why it was charging for tests? Who was leading the studies and what was the design? The commercialisation of antibody testing is a direct consequence of the absence of any governmental guidelines for private labs.”