Days after the Brihnamumbai Municipal Corporation (BMC) requested the National Institute of Virology (NIV) to send their waste water samples found RT-PCR positive for genome sequencing, the study has found that many COVID-19 patients continue to shed the virus through faeces, even as their nasal and throat swabs become negative.
According to the data revealed by NIV, Pune, out of the 280 stool samples that were studied in the genome sequencing, nearly 62 per cent had the presence of the viral RNA. This raises the possibility of the faecal-oral route of transmission of SARS-CoV-2 in developing countries, where patients are asymptomatically infected as they stay in crowded places, slums, etc.
Besides, Mumbai’s civic body is also in the process of starting wastewater surveillance. However, experts stated that it will be even more beneficial if carried out in areas with vulnerable populations such as old age homes or hospitals.
The study highlights that the viral particles within the faeces, if aerosolized, have great involvement in compact environments, such as cruise ships, hospitals, individual households, and densely populated housing, especially in regions with poor sanitation.
There are several potential risk factors and risky practices predisposing human health to risks in developing countries, such as poor wastewater management, poor sanitation and hygiene, high risk of co-infections, and lack of surveillance systems, promoting the SARS-CoV-2 faecal-oral transmission.
Moreover, the researchers found that coronavirus patients with complications or those admitted to the intensive care units (ICUs), shed the virus for a longer duration of up to 55 days, while asymptomatic or those with mild symptoms shed the virus in 28 to 40 days.
Earlier, this month, the civic body announced its plan of genome sequencing the COVID-19 positive sewage water samples.