COVID-19 infection detected in sewage of Mumbai slums

After Hyderabad, the coronavirus has now been found in the sewages of Mumbai. Scientists have detected the presence of SARS-CoV-2 (COVID-19 infection) RNA in sewage samples coronavirus in six slums, including the world's largest slum Dharavi. Apart from that, the sewage sample in the slums of Wadala, Shivaji Nagar, Kurla, Kanjurmarg and Malad has been detected with the coronavirus infections.

The study was conducted by ICMR’s National Institute of Virology, (Mumbai Unit). The researchers said that though COVID spreads mainly via the droplets of respiratory secretions, it was also detected in stool samples of patients, indicating active infection of the gastrointestinal tract.

For the study, sewage samples were collected from six sites in Mumbai using the grab sample method and processed using polyethylene glycol (PEG)-dextran phase separation method for virus concentration. Real-time RT-PCR assay was used to detect the presence of COVID RNA.

According to scientists, similar monitoring was done in 2001 regarding polio infection.

A total of 20 sewage samples were collected from six different wards in Mumbai, before the spread of the coronavirus infections and during May 11-22, 2020, were processed using the phase separation method. All samples collected before March 16, 2020, were COVID negative. Viral RNA was detected in sewage samples collected during the ongoing COVID-19 pandemic in all the six wards, the study said.

Scientists say that sewage water is examined in three layers. Except for the upper and lower layers, the COVID-19 infection was found to concentrate in the middle phase only.

Dr Deepa Kailash Sharma said that the world was first told about the coronavirus by scientists in the Netherlands. Shortly before, CCMB scientists in Hyderabad had also confirmed coronavirus in the sewage.

According to the study, the virus starts reaching the sewage within a week from the faeces of symptomatic patients after the infection is vulnerable. In addition to that, the infection can also reach the sewage through soaps, shampoos, washing powders etc. used during bathing of the infected patient.