Dr Manjula Meda
Chair, Healthcare Infection Society
Bacterial resistance to antibiotics is rising, and carbapenem-resistant superbugs are becoming more lethal than methicillin-resistant Staphylococcus aureus (MRSA), despite carbapenems being a last-resort treatment.
Widespread use and misuse of antibiotics in humans and animals over the last few decades has created a Darwinian pressure on bacteria, selecting only the most resistant bacteria to survive. This process is known as antimicrobial resistance (AMR).
Rising carbapenem-resistant infections
In hospitals, the most vulnerable patients are treated with broad-spectrum antibiotics because, due to AMR, narrow-spectrum agents like Penicillin can no longer be relied upon for treating serious infections. When patients require longer hospital stays, they risk developing hospital-acquired infections, which are treated with last-resort carbapenem antibiotics.
These drugs are increasingly less susceptible to resistant bacteria. As a result, carbapenem-resistant bacteria, known as carbapenemase-producing organisms (CPO), have emerged and stand to become a problem more deadly than MRSA.
The perfect breeding place
Patients receiving antibiotics will excrete between 10–90% of it in their faeces or urine, depending on the antibiotic type.1 These go down the drains of our homes and hospitals. In hospitals, excreted last-resort antibiotics enter drainage systems along with the trillions of bacteria that inhabit this same space. Hospital drains provide an ideal environment for drug-resistant bacteria like CPO to thrive due to warmth, moisture and frequent exposure to bacteria and antibiotics.
Patients receiving antibiotics will excrete
between 10–90% of it in their faeces or
urine, depending on the antibiotic type.
CPO spreads drug resistance
CPO share genetic material with different species of bacteria. This results in the spread of drug resistance in multiple types of bacteria. Laboratory experiments backed by outbreak investigations in hospitals have established that bacteria in drains can travel upwards and for long distances in waste pipes due to changes in pressure in plumbing systems. This results in plumes of resistant bacteria emerging from toilets, sinks and shower drains into hospitals, even when they are not in use.
Water-safe hospitals
The Healthcare Infection Society supports building hospitals which prevent AMR spread. To prevent CPO and bacterial transmission from drains, European hospitals have adopted water-safe patient care by redesigning and reducing hand-wash basins and shower drains. This minimises patient exposure to wastewater. Frimley Health NHS Foundation Trust is one of the first hospitals in the UK to begin to adopt this approach.
[1] Frade V.M.F. et al. Environmental contamination by fluoroquinolones, Brazilian. J. Pharm. Sci. 2014 doi: 10.1590/s1984-82502011000100004.
