The National Centre for Disease Control (NCDC) is studying sewage sample from seven sites in Delhi to check for coronavirus variants.
Officials at the Covid-19 review meeting chaired by Delhi Chief Minister Arvind Kejriwal on Thursday further said that these seven sites are: Batla House, Swan Cinema, Shahdara, Sonia Vihar, Wazirpur, Nangloi and Bhalswa Lake.
Officials further said that the BF.7 Omicron sub-variant, which is driving the Chinese Covid-19 surge, has not been detected so far in Delhi, according to sewage surveillance reports for the last four consecutive weeks.
CM Arvind Kejriwal's Covid-19 review meet
Officials shared that only 24 per cent of the eligible people have taken the precaution dose of coronavirus vaccine as on December 21. Only 19 per cent people in the 18-59 age category have got the booster dose so far.
Forty-eight per cent eligible people in the 60+ age group and 62 per cent of the healthcare workers and frontline workers have received precautionary dose.
In the meeting, Kejriwal said his government is fully geared up to tackle any eventuality. He added that the dominant sub-variant in Delhi is XBB that has been detected in 92 per cent of the samples till now.
At the moment, 2,500 tests are being conducted and these can be increased to one lakh if there is a surge in cases, said Kejriwal.
How wastewater analysis helps?
Analysing sewage or wastewater is a worldwide public health practice which gives crucial insights into the disease spreading in an area.
The idea behind testing sewage is that infected people also shed virus when they use the toilet. While shedding virus from nose or mouth while breathing is most common, people also shed virus in stool they pass. Notably, virus is shed in stool for a longer time.
Therefore, experts check for sewage which carries stool to study viral spread in an area.
“Regularly analysing wastewater from sewage treatment plants allows scientists to measure when those levels are rising or falling and what variants are present about four to five days before people start testing positive,” notes a piece in The Washington Post.
Sewage analysis gives them a number of insights.
Earlier this year in Houston, United States, high viral presence in wastewater did not accompany an increase in hospitalisations, according to The Post, which suggests that disease is mild which is causing infections but is not making people sick.
A study by India’s National Institute of Virology, Pune (NIV Pune) made scientists conclude that there is a high possibility of Covid-19 outbreaks in poor areas in developing countries through faecal matter. They found that people shed the virus in faeces for weeks after testing negative.
"This creates a possibility of infections through contact with faecal matter in developing countries where patients are asymptomatically infected as they stay in crowded places and slums, according to the study published in March.
(With PTI inputs)
