Holy waters, unholy outcomes!
Rivers are revered and considered holy since times immemorial in India and mass bathing in some rivers is an age-old ritual. A holy dip and a holy sip of the river waters are considered to be a highly purifying. But is the dip really cleansing at all when almost all the rivers in India are known to be highly polluted? Evidence shows that large amounts of sewage and industrial wastes, agricultural and pharmaceutical effluents continue to be regularly dumped into majority of the rivers in India rendering them highly polluted.
Dangers lurking behind this uncontrollable poisoning of rivers
Rivers that are highly polluted with human faecal matter and livestock waste are often found to harbour Escherichia coli (E. coli), a type of bacteria that normally resides in the gut of humans and animals and can be harmless, but some of the strains can be toxic leading to diarrhoeal diseases among people who drink this water.
The presence of these bacteria in the river waters and sediments that are loaded with antibiotic residues from the industrial and pharmaceutical effluents can often make these bacteria resistant to antibiotics leading to the development of antibiotic resistant bacteria or what can be called as superbugs. Not only can these bacteria get into the human gut through bathing and drinking of this contaminated water, but can travel through the water to distant sites and spread into other freshwater bodies.
What is antibiotic resistance
Bacteria have a remarkable capacity to adapt and survive in adverse environments. When bacteria encounter antibiotics mixed in river waters over long periods of time, they evolve mechanisms to withstand or resist the effects of antibiotics targeted to destroy them and fight infection by changing themselves. They can do so by secreting enzymes that can inactivate the antibiotic, change the permeability of their cell membranes to prevent entry of the antibiotic etc. These microorganisms that develop resistance to multiple antibiotics are also referred to as ‘superbugs’.”
When superbugs develop resistance to a particular antibiotic used to treat infections like say diarrhoea, the antibiotics can become ineffective. This will result in the person continuing to suffer from the condition which could even become fatal, increasing the risk of spread to others.The presence of antibiotic resistant bacteria in freshwater sources has been documented throughout the world and in India as well and has been now indicated as a major threat to human health in the coming years.
The holy river Kshipra
River Kshipra in Madhya Pradesh is a source of domestic water supply for the city of Ujjain and nearby areas. Due to the religious importance of Kshipra River, mass gatherings including mass bathings at large and small scales continue to be held throughout the year on its banks.
While mass bathings continue, and are known to lead to a significant deterioration in the water quality of river Kshipra, there are no systematic studies that have looked at the impact of the mass bathings on river water quality, especially from the point of view of bacterial contamination in the context of the growing threat of antibiotic resistance in Indian rivers.
A study titled ‘Mass bathing events in River Kshipra, Central India- influence on the water quality and the antibiotic susceptibility pattern of commensal E.coli’ published in the journal PLOS One attempts to assess the extent of contamination of the river water and river sediment in pre, during and post mass bathing events in river Kshipra.
The study tested water samples collected from River Kshipra, in its 93 km flow through Ujjain district, before, during and after mass-bathing events. The study found that:
- The water quality of the river deteriorated
There was a significant deterioration in the water quality of the river. High Total Dissolved Solids (TDS) and free carbon dioxide were found during bathing while high Total Suspended Solids (TSS), total and organic phosphorus, Biological Oxygen Demand (BOD) and Chemical Oxygen Demand (COD) were detected in post bathing periods in the river Kshipra. Thus, water quality parameters of the river were found to be poor making the water unfit for use for drinking or household purposes.
- The river waters showed high bacterial contamination
The increase in bacterial count in the river water during and post-bathing was found to be due to mixing of river sediment bacteria with the upper layer due to constant and heavy movement of water by movement of number of people during mass bathing. Presence of bacteria was also influenced by seasons. Thus, a high number of E.coli bacteria were found in the river water and sediment in events that took place in monsoon and summer with the count being the highest in summer.
- The river sediment had high number of antibiotic resistant bacteria
Antibiotic resistant and multidrug resistant coliforms were found in 20 to 38 percent of the samples from the river water and river sediments raising concerns regarding risk of bacteria acquiring multiple antibiotic resistant genes via horizontal transfer to a wide range of bacterial species. The number of E.coli were about 200 to 300 times higher in river sediment during summer season making it an important reservoir of resistance genes.
- The river water served as a rich source of antibiotic resistant genes for new pathogens
The river water served as a medium for mixing of pathogenic and non-pathogenic or commensal (intestinal friendly bacteria found in the gut of humans who are normally non – pathogenic) bacteria from many sources like human, animal and environment. However, it was found that a high percentage of non pathogenic E.coli were co-resistant to antibiotics such as quinolones and cephalosporin indicating that pathogenic bacteria may exchange antibiotic resistance genes with non-pathogenic or commensal bacteria.
The study concluded that the health risk due to bathing and drinking of water in the river was very high due to the presence of highly resistant intestinal non-pathogenic bacteria in the waters calling for the urgent need to:
- Have improved guidelines on surveillance of water quality and of antibiotic resistance during mass bathing festivals
- Develop effective prevention and control strategies to avoid or minimise the risk of transmission of antibiotic resistance through waterborne coliform contamination at the policy level.
By Manju Purohit, Vishal Diwan, Vivek Parashar, Ashok J. Tamhankar, Cecilia Stålsby Lundborg