A fifth sentinel survey conducted by the health department found that the Covid-19 positivity rate in nine districts of West Bengal was more than 10 per cent last week, an official said on Monday.
The survey, conducted from July 7-8, revealed that the test positivity rate (TPR) had crossed 20 per cent in some areas also.
The findings forced the department to earmark at least 11 places as red zones, the official said.
“Murshidabad is the only district where the positivity rate is below 1 per cent,” the official said. In the ‘health district’ of Nandigram, the TPR was 24.6 per cent, followed by 23.75 in North 24 Parganas and 19.10 in Darjeeling. Uttar Dinajpur in fourth place with a positivity of 16.25 per cent, the survey found. The TPR in Paschim Bardhaman was 18.56 per cent, while it was 17.85 in Kalimpong and 14.38 in the ‘health district’ of Basirhat. Howrah has a TPR of 14.23 per cent, followed by 14.14 in Purba Bardhaman, 13.13 in Kolkata and 10.15 in Nadia. Nine districts and health districts with a positivity rate of 5-10 per cent are listed as yellow. Six others have a TPR between 1-5 per cent, the department said. Sentinel surveillance is the monitoring of the rate of occurrence of a specific disease through a voluntary network of doctors and laboratories, aiming to assess the stability in health levels of a population of a particular region. For the survey, 400 samples were collected from every hospital in the 23 districts and health districts of the state. PTI