COIMBATORE: With new positive cases on the decline, the health department is planning to conduct the next round of the serum surveillance survey in ten districts to ascertain the trend.
According to sources, the ten districts are chosen based on the seropositivity rate during the earlier test. The last serum surveillance survey was conducted in June and results were declared in July. As per the study, Virudhunagar (84%), Chennai (82%), Madurai (79%), Tenkasi (78%), Theni (77%) had the highest sero-positivity ratio while Erode (37%), Coimbatore (43%), Nagapattinam (47%), Namakkal (48%), and Karur (51%) recorded low seropositivity rate.
Speaking about the intension of the study, Director of Public Health T S Selvavinayagam said: “We are reconfirming our testing of the recently concluded survey. So, the top five and bottom five districts in the survey result were selected for the survey.”
He said there might be a slight rise in the seropositivity ratio because of the effect of Covid-19 cases recorded and vaccination done in the past one and half months.
In Coimbatore, sources said that the samples would be collected from only half of the clusters from the recently concluded serum surveillance survey. An official, privy to the developments, said, “This time, the department would collect samples from only 22 clusters, instead of 42 clusters earmarked during the previous survey. About 660 blood samples shall be collected randomly to check for presence of antibodies.”
Sources said the move to conduct a serum survey amidst the plateauing Covid tally would give an idea of the trend. “Since the samples are collected randomly from residents, anyone from the concerned locality above 18 years would be approached,” an official said adding that the process would start once the government gives the green signal.
Officials pointed out that positivity ratio of Coimbatore was the lowest and needs to be improved with a push of vaccination.