Telangana government’s decision to set up 31 Sewerage Treatment Plants (STPs) for dealing with wastewater generated by the twin cities had piqued interest among many a scientist as it will serve as a perfect stage to incorporate wastewater surveillance into the One Health research and pandemic preparedness.
“Wastewater or sewage sample is the ‘reporter’ for the entire population of the city, giving a snapshot of the pathogens present, drugs and chemicals being used. The current estimate of pathogen load is a gross underestimate as many people may not even go to the hospital till the situation becomes grave. So, monitoring sewage is the best way of having a good estimate of pathogens in the population,” says Tata Institute for Genetics and Society director Rakesh Mishra.
The scientist, a former director of CSIR-Centre for Cellular and Molecular Biology (CCMB), points out that sewage monitoring is not a novel technique as it has been used to check for polio cases for over two decades. During the COVID pandemic, the protocols were optimised to keep a watch on potential spike in cases and monitor for a new variant circulating among the population.
“During the pandemic, it had become very handy as we could predict a wave 10-12 days beforehand, enabling the local governments to prepare for necessary action in the affected area. We could decipher if the spike was because of a crowded activity/event or due to new variant,” he explains.
What Mr.Mishra suggests is that the government put a system in place where trained personnel collect up to 50-100 samples from the STPs in Hyderabad once every 1-2 weeks to monitor the pathogen prevalence. This continuous supply of STP-level granular data will be an effective way for preventive healthcare systems, and to take appropriate measures if something unusual is noticed in the samples.
“Wastewater monitoring has become important because treated water from the outlet is often used for irrigation, plantations, leafy vegetables, cattle, etc. If not monitored properly, some of the pathogens may reach the human palate through milk or uncooked food. We are all connected with our environment and cannot live in a bubble,” says the top scientist.
Government mandate for the local municipal body or public health department to pool in samples for testing in a certified lab does not require big resources or huge equipment. It also could be another method of keeping a tab on the functioning of the STPs themselves.
“The biggest advantage is that it is cheap, non-intrusive, won’t disturb any person, and will give a real reflection of the health status as we found out during COVID. The protocols have turned out robust and the data is quite authentic. Hyderabad is privileged to have premier laboratories like CCMB, IICT, CDFD, etc., that are competent to help train or set up the necessary infrastructure to even cover sampling from open drains or water bodies,” he affirms.
This DNA/RNA-based environmental surveillance procedure can be used quite effectively to check for incidences of dengue, malaria, tuberculosis, common flu, bird flu, and other infectious diseases among the populations or environment in specific areas, added Mr.Mishra.
