Serological Survey-30,000 samples to be collected from 888 clusters in TN
Posted on: 21/Oct/2020 9:12:24 AM
Soon, the directorate of public health or DPH would become very busy in conducting serological surveys. This survey would be conducted in as many as 45 health units across all the districts of TN.
The health officers would collect atleast 30000 samples from as many as888 clusters and these samples would then be tested in the public health labs. The other name of these tests is antibody tests and the tests would estimate the number of people previously infected with Covid-19.
It has been pointed out by Dr. T.S. Selvavinayagam, director of public health that the information collected would make TN state government make public health decisions during the pandemic.
He explained that there would be atleast 30 samples collected from each of these clusters. He mentioned that people from whom the samples would be collected might or might not have been infected with covid-19 infection. The objective behind was to see the presence of antibodies for SARS-CoV-2 virus in the people.
Point is that antibodies are proteins that would help us to fight the infections. It must be noted that antibodies are specialised protein molecules that are produced by the immune system in response to foreign invaders called antigens.
Working process:
It is believed that the antibodies with Y shaped structures bind with a matching site on the antigens. This would result in the destruction of antigens and finally the infection is avoided.
There are 123 clusters in Chennai and Coimbatore has 42 clusters. Districts like Madurai and Trichy have got 38 and 322 clusters respectively. According to some public health officials, the samples would be collected from both rural as well from the urban regions of all the districts in TN.
It was highlighted by Dr. Selvavinayagam that active cases would be excluded from the test and those with ILI symptoms like fever, cold, sore throat, runny nose, headaches etc would not qualify for the test. For diagnosis purposes, it cannot be used.
Information collected is that scientists at the public health lab at Anna Salai would use chemiluminescent immunoassay or CLIA technique for the test.
Emission of electromagnetic radiation caused by a chemical reaction would be used by this CLIA to produce light and identifying antibodies. It was brought to light by Mr. J. Radhakrishnan, health secretary of Tamil Nadu that there was no clarity on whether higher percentage of antibodies would mean people were close to herd immunity.
