Sars-CoV-2 traces found in sewage under research

NEW DELHI: Traces of Sars-CoV-2 have been found in sewage samples in Gujarat, prompting a central agency to study whether contaminated sewage can cause infection. Only Gujarat has so far reported the presence of the virus in sewage, “and we need to see if other states also report it,” the official added.

NEW DELHI: Traces of Sars-CoV-2, the virus that causes Covid-19, have been found in sewage samples in Gujarat, prompting a central agency to consider strengthening surveillance and study whether contaminated sewage can cause infection.

“The next step is to determine whether there is risk of infection through this channel or not. However it will still take some time before we start on that as currently there are several surveillance initiatives that need immediate attention,” said an official in the Union ministry of health, requesting not to be identified.

Only Gujarat has so far reported the presence of the virus in sewage, “and we need to see if other states also report it,” the official said. “We will continue sample testing for some time.”

“We have World Health Organisation (WHO) reference lab for polio surveillance which conducts tests on regular basis on sewage samples to check for the presence of polio viruses. The same lab and its surveillance system is being used to monitor the presence of Sars-Cov-2 in sewage,” said the official.

NCDC, which spearheads all disease surveillance in the country, along with its partners, began sewage sample testing around April. The focus states were Gujarat, Maharashtra and Delhi.

“Though there is enough evidence to prove that the disease does not follow the faecal–oral route of transmission, there is no harm in expanding the scope of disease surveillance to be able to know the spread of the disease better, especially since we have a monitoring system and an advanced lab in place for the purpose,” said an official in NCDC.

Sewage sample testing can be a good surveillance tool along with sero (blood) surveys, say experts.

“SARS may have spread through sewage in Hong Kong and now new data on infectious SARS CoV-2 in stool . ... we should think about more sewage sampling,” tweeted Gagandeep Kang, physician-scientist and faculty, Translational Health Science and Technology Institute.