Ahmedabad’s wastewater scan shows Covid, hepatitis viruses lurking

Slug: 4-City StudyAhmedabad: What if a city’s sewage system could function as a giant public-health scanner, quietly revealing which viruses are circulating among millions of people long before they appear in clinics and hospitals?Just one year of wastewater surveillance in four Gujarat cities — Ahmedabad, Gandhinagar, Vadodara, and Rajkot — has yielded 170 DNA and 135 RNA virus species for state-based biotech researchers.These viruses included Covid, adenovirus, influenza, hepatitis, and rotavirus. Surveillance also showed the vast diversity in strains that were specific to animal and human sources.Healthcare experts said that surveillance — which primarily takes the data from wastewater — is used worldwide as an early warning system. During the Covid period, experts noted a virus spike in wastewater before cases started increasing in city-based hospitals and clinics.The study ‘Longitudinal wastewater virome surveillance unveils untapped circulating viruses in the community’ by the researchers from Gujarat Biotechnology Research Centre (GBRC), Gujarat Technological University (GTU), and Gujarat Biotechnology University (GBU) was published recently in the Nature Portfolio Journal Emerging Contaminants.The researchers collected wastewater samples every two weeks for a year from 24 sewage treatment plants and pumping stations serving an estimated population of 1.65 crore in four cities.

It helped the researchers capture the diversity and seasonal variations.“In Vadodara, high prevalence was observed for members of the Astroviridae family, Adenoviridae in Rajkot, Polyomaviridae in Gandhinagar, and Parvoviridae in Ahmedabad,” the study said. “The Coronaviridae family SARS-CoV-2 showed consistent detection in Gandhinagar and Rajkot, with the highest prevalence in Vadodara, followed by Ahmedabad.”The study said, “Certain viruses such as Chicken anemia virus and Avian gyrovirus 2 were more prevalent in Ahmedabad.”It added, “Additional families, including Luteoviridae (Bat luteovirus), Flaviviridae, and Hepeviridae (Hepatitis E virus type 1), were also detected in Ahmedabad, indicating the presence of both human and animal viruses in the community.”Astrovirus causes diarrhoea; adenovirus is responsible for infections in the respiratory tract, eye, and GI tract; parvovirus causes flu among children; and polyomavirus attacks immunocompromised individuals, said city-based physicians.Researchers said that they also compared the data with lab results and overall prevalent trends in the cities that further proved the usefulness of the method.Public health experts suggested sharing data — especially in light of zoonotic diseases and the concept of One Health — with health departments and city administrations to enable timely intervention.