ICMR’s antibody test study underlines need for more testing, and better contact tracing
The results of a serological test conducted across 69 districts by the Indian Council of Medical Research (ICMR)
have indicated that the confirmed numbers of COVID-19 infections
reported from the RT-PCR tests are likely an undercount. Serological or
antibody tests are not as accurate as the PCR tests, but they are useful
indicators of the spread of the novel coronavirus among people. The
ICMR study found that 0.73% of the population, examined for antibodies
produced specifically for SARS-CoV-2 via an ELISA test,
had evidence of past exposure to the virus. In a population with a low
infection rate, there is a higher possibility of “false positives” being
reported. A number of respondents could have been found to have
released antibodies specific to coronaviruses, but without actual
exposure to SARS-CoV-2 alone. But the ICMR in its methodology note in a
paper in its online publication, Indian Journal of Medical Research, had
said that the actual results would account for the limitations of the
ELISA test. If this is accepted, then the number of people found to have
been exposed to the virus would be 7 lakh people or more, if the
overall population of these districts is considered, much higher than
the 35,000 people who had tested positive in the entire country during
this period. The full paper detailing the results of the study by the
ICMR is still not out in the public domain. Serological tests, despite
inaccuracies, can be a useful guide of the extent of the infections
among vulnerable people and within hot spots, and periodic tests of this
kind are a must amid the rise of cases that have now crossed the 3.2
lakh mark. The clear takeaway from this report is not what the
Director-General of the ICMR claimed that there is no evidence of
“community transmission”, but that there has not been adequate testing
by the more accurate RT-PCR method.
While the “lockdown” strategy
might have slowed down the rise in cases and fatalities in the early
period of the outbreak in the country, the severe effect it had on the
economy, besides its uneven implementation in urban areas where physical
distancing is a difficult proposition, made it an untenable strategy to
pursue over the longer term. India continues to register among the
highest daily rises in COVID-19 cases and fatalities world-wide and this
has now burdened the health institutions in many urban centres
following the easing of the lockdown. Yet, authorities continued to test
at relatively low levels with a lot of variance across States. Some
States such as Maharashtra and Gujarat have tested at a higher rate
(tests per million population) than many others, but have not increased
the overall testing to account for the relative rise in the size of the
outbreak. Telangana has still not ramped up testing numbers adequately
and has been opaque in the release of testing data. Testing, tracing and
treatment at a higher order across the population besides measures such
as mask wearing and practising hand hygiene, as the experience of
several countries that have considerably slowed down the rise in the
case count shows, is the clearest way to address the outbreak.
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