Hyderabad: The TS government sent just one sample for genome sequencing of SARS-CoV-2, the virus that causes Covid-19 in July. Genome sequencing is needed to map the spread of the highly infectious Delta and Delta plus variants of SARS-CoV-2.
This represents a steep fall from the 704 samples sent in April, 1,033 in May, and 476 in June. Most of the samples were sent from private hospitals.
The state sending 3,000 to 4,000 samples for sequencing per month, given the capacity to do so at the Centre for DNA Fingerprinting and Diagnostics, and the Centre for Cellular and Molecular Biology, both located in Hyderabad, according to public health experts.
Once the results are in, they are sent directly to the Chief Minister who holds charge of the health portfolio.
Between March 2020 and March 2021, only 1,911 samples were sequenced from the state, far less than 4,124 that were collected. The number of samples sequenced in the country till August 4 was 47,000.
During the ongoing second wave, swabs have been collected from April onwards from two centers each in Hyderabad, Nagarkurnool and Wanaparthy, along with three locations in Vikarabad, 13 in Warangal and 24 in other districts.
Genome sequencing from April onwards showed that the presence of the Delta variant increased in the state from 50 per cent of the samples sequenced to 94 per cent in May and 95 per cent in June. Another 12 per cent of other variants have been recorded in the state.
Samples for sequencing are sent from clusters of cases in a particular area, those reporting many severe cases and those collected from travellers. The state border areas abutting Maharashtra, AP and Chhattisgarh, require collection of more samples but due to infrastructure issues only a few samples, most of them from urban areas, are sent for sequencing.
Samples collected from travellers at the Shamshabad airport are sequenced separately.
A senior government doctor said samples were collected aggressively in the initial stages of the second wave. “Once there was decline in new cases, the pace of sample collection reduced,” the doctor said.
Gandhi Hospital and Telangana Institute of Medical Sciences and Research are the nodal centres but the sample collection from these two hospitals is learnt to be minimal.
A senior scientist at CCMB, on condition of anonymity, said “Telangana has been lucky as there were not enough samples sent from the beginning. They have not been taking sewage samples like what is done in Karnataka and Maharashtra. During the declining stage too, tracking and tracing requires collection of samples from humans and sewage to understand the activity of virus.”
Dr Rakesh Mishra, adviser and CCMB scientist, said, “Genome sequencing does not mean finding only new variants. It means tracking and tracing existing as well as identifying the variants of interest and concern. There will be some variants which are only in a particular location and not move anywhere and die out there too. These are constantly changing dynamics but a recorded variant helps to trace it.”
