The level of antibiotics flowing into the River Thames must be reduced by up to 80% if the risk of developing and transferring antibiotic-resistant “superbugs” is to be prevented, it has been reported.
Scientists from the Centre for Ecology and Hydrology (CEH) simulated the impact of antibiotic prescriptions on the emergence of antibiotic-resistant bacteria in a river. It established that in three-quarters of the River Thames catchment, the antibiotics present as a result of effluent discharge were likely to be at high enough levels for antibiotic-resistant bacteria to emerge.
The research follows England’s top medical officer professor Dame Sally Davies’ warning last week that antibiotic-resistant bugs posed a more imminent threat to humanity than climate change, and could kill at least 10 million per year worldwide.
Dr. Andrew Singer of the Centre for Ecology and Hydrology, who conducted the research, explained, “Rivers are a ‘reservoir’ for antibiotic-resistant bacteria which can rapidly spread to humans through water, soil, air, food and animals. Our beaches pose a similar threat. It has been demonstrated that surfers are four times more likely to be carrying drug-resistant bacteria than non-surfers.”
How antibiotics end up in our rivers?
Up to 90% of prescribed antibiotics taken by people pass through the body and into the sewerage system, where about half end up in rivers when effluent is discharged.
“The discharge of bugs and drugs into our rivers makes it more likely for antibiotic-resistant genes to be exchanged, either by mutation or ‘bacterial sex’. This is the beginning of the formation of superbugs because the drugs employed to combat them will be useless,” Singer elaborated.
“Environmental pollution due to bugs and drugs is a big issue that we have to solve.”
The research, led by the CEH, used prescription data from clinical commissioning groups for two groups of antibiotics–macrolides like erythromycin and azithromycin, and fluoroquinolones like ciprofloxacin, levofloxacin and moxifloxacin.
Macrolides cure a variety of respiratory and sexually transmitted diseases like pneumonia, whooping cough and chlamydia, while fluoroquinolones cure respiratory and urinary tract infections. These were selected for the research because they slowly biodegrade whereas other antibiotics like penicillin biodegrade before reaching the river.
Possible solutions
There are several different methods by which could minimize the amount of antibiotics that reach rivers, including:
- Cutting down on inappropriate prescriptions, either because the antibiotics won’t work to cut the infection, or the treatment course is longer than medically required.
- Preventative measures so less medicine is required in the first place, such as faster diagnosis of medical conditions, higher take-up of vaccinations for disease and improved hygiene controls within hospitals.
- Increased investment in the research and development of new wastewater treatment technologies that would eliminate the bugs and drugs from sewage.
The Government and health professionals agree that limiting the prescribing of antibiotics is essential in addressing antibiotic resistance, and total antibiotic consumption in primary and secondary care in England decreased by 6.1% between 2014 and 2018.
Yet, prescriptions of antibiotics per capita in the UK per capita remains greater than that of some European nations and twice that of the Netherlands, where their prescribing controls on antibiotics and effective hygiene within the healthcare system have seen relatively low levels of antibiotic resistance.
Source: Centre for Ecology and Hydrology
