Covid: Is it community transmission?

Naina Mishra

Tribune News Service

Chandigarh, January 5

The positivity rate of the city has jumped from 0.95 per cent to 12 per cent since December 23 even as the number of samples collected for Covid-19 remains the same over the past two weeks.

Chandigarh is now among 10 states that have a positivity rate of more than 10 per cent. Experts have suggested the high positivity rate as an indicator of community transmission. Dr Suman Singh, Director, Health Services, said, “Over 50 per cent of our samples are from patients coming to OPDs for non-Covid ailments. The positivity rate among those samples has also gone high, which means there is high transmission in the community. Another subset of samples is from those who are high-risk contacts of positive patients. The Omicron variant is reported to be 40 times more transmissible than the Delta variant. We have sent samples of random people for genome sequencing to find out the variant causing the spread this time.”

“We have also noticed that mostly patients who are turning positive are asymptomatic and do not require hospitalisation. Many are in home isolation,” she said. The total positivity rate (TPR) is the percentage of all coronavirus tests performed that turn out to be positive, and detect the presence of the virus. According to the criteria published by the WHO in May 2020, a TPR of less than 5 per cent is one indicator that the infection is under control in a locality.

It may also be mentioned that around 28 per cent of the samples collected by Chandigarh are from the Rapid Antigen (RAT) technique, while 72 per cent are taken with the RT-PCR method.