In a fish market you can hardly
hear yourself speak. The Social Media and MSM have become not too different. We
have many voices speaking at the same time, all at high decibels, it has become
difficult to glean information from this media created tumult.
There are many people who are
very vocal that ‘Testing’ is the solution and then go on to build a nebulous
connect between ‘Testing’ and ‘Control over Covid-19 virus’ aka ‘Chinese Virus’.
The need for testing has been repeated so many times by so many opinion makers
that the public seems to have ceded that without ‘Testing’ we have no solution
to defeat the virus.
Those who think slow will agree
that ‘Testing’ has a purpose, as a bare minimum.
In India, I believe predominantly
PCR Testing being is being conducted to detect presence of the virus in a
population that came in contact with infected persons and to confirm the
presence of symptom in persons showing symptoms.
From this group if few were
infected and showed no to mild symptom, they probably got immunity and no test
was done to confirm and no effort to collect the data.
What will PCR test reveal? If a
person is infected or not.
The pro-more-test are asking for
increasing the target population to entire population. From whatever little
tests we have carried out on general population has shown about less than 5% have
been affected. We know what to do with them.
What about the 95% of the tested but
negative? The results help us with little value because we only know that these
are not infected yet and may be infected in future.
While testing the people who had contact
with infected person(s) this may be useful as the infection may be detected
early and any treatment that may yield benefit may be begun early to reduce the
risk of deterioration.
However, the antibody test may be
conducted on a population not known to have come in contact with infected
population to measure the spread of the infection in general population.
This testing can be at best be a ‘Sample’
testing. Appropriate decisions can be taken based on the outcome.
The Antibody test may
reveal that a person has been infected. But it is not so simple. The symptoms
in majority of cases appear along with the peak viral replication. AND, in
earlier stage the risk of false negative for antibody test is high. The
antibodies are made post infection and around the 5th day of the
infection may become detectable, by which time most infected have begun to show
symptoms. The effort to identify an infected person using antibody tests in
early stages is too high in comparison to PCR test.
If an area shows more prevalence
than the rest, this test helps to conduct PCR tests to identify the carriers
and to isolate them early. Antibody tests are bellwether tests.
Summing up, PCR tests on everyone
is not only expensive but also needs to be repeated till everyone is tested
positive. Antibody test “alone is not recommended for COVID-19 diagnosis due to
the kinetics of infection” Link
here
Antibody testing of, say 500K
tests a month spread over different places after the lockdown will be very
useful to check if the infection has risen its head again; if any particular
region is seeing more than the other.
However, what we fail to identify
is, I assume in the absence of any positive communication from authorities, the
number of recovered people. These are people who have lower chances of relapse,
hence have low probability to carry to uninfected people. Kind of asset.
By not testing for antibody, we
also miss out on the number of people who may have acquired immunity as many
people show no to mild symptoms.
The cost of conducting one round
of antibody testing may be around 6 lakh crores according some sources. Tests
may have to be repeated on same population albeit on smaller and smaller numbers.
This is not a feasible solution.
Conclusion is, PCR Testing for
presence of Corona in target population that had contact with infected persons pays
high dividend and is being done by the Govt of India
Antibody testing is being
conducted as sample (there is no hurry to cover the entire country) and will identify
high risk areas.
Now request those who are
repeatedly asking for more testing, kindly be specific, what kind of testing
are you pleading for? Unless that is made clear, do not expect any sensible response.
May be few will join the mindless chorus of worthless effort. Nothing more.
