Faced with increasing cases of Delta variant of Covid-19, the Centre has recently asked states to ensure sending a “requisite number” of samples for whole genome sequencing, increase the number of sites taking such samples if required and update the Centre with the clinical and outcome details of every person whose sample is sent for the genome sequencing.
News18 has accessed a letter in this regard written to the states by Union Health Ministry’s Additional Secretary Arti Ahuja in which she has highlighted “the rising proportion of the Delta variant in many districts of the country which experienced a surge in April and May.” Ahuja in the letter dated June 18 has also flagged off other variants emerging in countries like Vietnam “which can have implications for India”.
The Centre on July 7 said the four Variants of Concern (Alpha, Beta, Gamma and Delta) were found in 174 districts in 35 states/UTs while Delta variant, first observed in Maharashtra, was associated with the unusual case rise in several districts of Maharashtra and “is now found in many states in India”. The Centre fears Delta and Delta Plus variants (which has an added mutation) pose a big challenge in stopping a third Covid wave.
India has recorded 56 cases of Delta+ variant in 12 states till June 30 and many more states have reported such cases since.
To address this, states have set up sentinel sites, which include RT-PCR labs and tertiary health care facilities, from where RT-PCR positive samples are sent for Whole Genome Sequencing to 28 INSACOG laboratories. The Centre’s letter said states may set up more sentinel sites if a need is felt for adequate representation of all districts and each sentinel site must send 15 samples each in every 15 days to INSACOG. States were asked to ensure the “requisite number” of samples are sent.
“Clinical-epidemiological correlation is also important for public health response. Hence, it should also be ensured that the clinical and outcome details of every person who sample has been sent for Whole Genome Sequencing are updated, and shared,” the Centre’s letter said, attaching a proforma for this.
The Centre on July 7 said the highest numbers of the four Variants of Concern have been reported from districts in Maharashtra, Delhi, Punjab, Telangana, West Bengal and Gujarat. Initially, genomic surveillance was focused on the variants carried by international travelers and their contacts in the community through sequencing 3-5% of the total RTPCR positive samples. Subsequently, the sentinel surveillance strategy was drawn up in April 2021 under which multiple sentinel sites were identified in states to adequately represent the geographic spread of a region, and RTPCR positive samples are sent from each sentinel site for Whole Genome Sequencing.