Testing within the Indian context is incredibly challenging as sewage systems are fragmented. Only a third of all towns have any style of sewers, either underground or open drains, in line with the 2011 Census. The remainder of the population is served by on-site sanitation, including septic tanks. Testing these is problematic and can be possible as long as there’s a scientific process of emptying and treating faecal sludge.
Most of the time, sewers and septic tanks are cleaned manually exposing men to a different potential pathogen, although the virus in sewage is alleged to be non-infectious.
The large population of cities complicates the prediction of infections supported sewage testing as these individuals could use toilets in their offices or public toilets. Therefore, if virus traces were found from sewage in these areas, tracing COVID-19-positive patients would be like finding a needle in a haystack.
The cost benefits of every part of the WBE protocol must be analysed. Sewage testing of households in hotspots would be more valuable than testing sewage from hospitals designated to treat COVID-19 patients. But this could hold true given that the sewage test was simpler, faster, and cheaper than individual tests.
The test data was time-sensitive; a negative result on at some point could indicate no infections, but things could change within hours with new people getting infected.
Sewage and faecal sludge treatment could be a problem not just in poor or densely populated areas but in affluent areas furthermore. In Bengaluru, as an example, that there are quite 500,000 on-site systems comprising pit toilets, community septic tanks, and temporary toilets.
It is also important to require into consideration the movement of sewage. In most cities, it flows through an unlimited hinterland. within the case of Bengaluru, for instance, treated sewage from the formal STPs flows up to 90 km from town, filling up lakes and recharging aquifers within the process. Farmer unwittingly draws such water through shallow open wells for agriculture.
India features a good distance to travel to require the advantage of this non-invasive method. It will be a robust tool in low-income areas but these communities, who is also most in danger, are the toughest to achieve with follow-up actions. Urban sewage/faecal sludge infrastructure that forms the premise of this method is in bad condition and should undermine the efficacy of this method of predicting the pandemic.
The COVID-19 pandemic provides an ideal entry point for promoting sewage testing but over that, for upgrading infrastructure and ensuring equity in access to safe and good quality sanitation.