Sanitisers hand us a new problem
Alcohol-based replacements for water may fuel bacteria proliferation
Cape Town has stared down a drought that threatened to shut down its water supplies, which would have been a disaster resulting from a catastrophic climate event in a city of 3.74 million.
When the winter rains came a few months ago, the city celebrated the end of a crisis mitigated through an extraordinary display of civic-mindedness, moral solidarity and good luck.
A small but significant water-saving measure was the widespread introduction of hand sanitisers. Typically, only one tap runs now in public-access toilets to encourage people to use wall-mounted hand sanitisers instead.
But, as any student of evolution would immediately realise, this may contribute to a new problem. The hand sanitisers are alcohol based, and certain bugs (bacteria such as Enterococcus faecium and Clostridium difficile in particular) are increasingly able to tolerate, survive and flourish in this environment, while others are knocked out efficiently. Bacteria — free-living organisms — predate humans by millennia and their gene code reflects a long record of survival mastery against many odds.
Hand sanitisers were introduced into hospitals decades ago as part of the infection control regimen required to keep down hospital-acquired infections. There are World Health Organisation-approved hand sanitisers, consisting of up to 60% ethyl alcohol that would blast most bacteria into oblivion.
THE HAND SANITISERS ARE ALCOHOL BASED, AND CERTAIN BUGS ARE INCREASINGLY ABLE TO FLOURISH IN THIS ENVIRONMENT.
Except for some. Microscopic bacteria travel in groups of billions and make copies of themselves every 30 minutes. The alcohol-tolerant bacteria flourish and colonise human bodies with breathtaking rapidity, evolving a fresh round of hospital-acquired infections.
At a recent workshop hosted by Jomo Kenyatta University of Agriculture and Technology in Kenya and Columbia University in the US, infection control and antimicrobial resistance experts Lisa Saiman and Elaine Larson pointed out that alcohol-tolerant bugs at hospitals have become a global challenge.
In the US, Clostridium difficile, or C. diffe, is a rising problem. This type of bacteria is most often found in hospitals, and is responsible for 20% of antibiotic-associated diarrhoea and causes 29,000 annual deaths in the US.
C. diffe survives alcohol-based sanitisers because of its hard shell. The only way to get rid of it is vigorous hand washing using soap, which flushes the bacteria down the drain.
Saiman and Larson pointed out that many alcohol-tolerant bacteria are also resistant to multiple drugs. A recent study by Sacha Pidot and her colleagues, published in Science Translational Medicine in August, found that half of the bacterial strains in their study could not be treated by vancomycin, a last-line antibiotic, thereby elevating health and death risks. They are calling for a new round of antibiotics, but very few are in development.
Until that happens, infection prevention measures in hospitals and clinics should be upscaled and focused on hand hygiene, employee health, tuberculosis screening, resident and staff immunisation, antimicrobial stewardship, food and kitchen sanitation, medical waste removal, education and training, and oversight by infection prevention, control and antimicrobial committees that collect evidence, monitor compliance, evaluate the effectiveness of interventions and correct underperformance.
Measures to improve the accuracy and speed of diagnosis must also be continuously improved. This includes the smart use of affordable new technologies, specimen selection and collection, turnaround time techniques, specimen storage and transport, specimen analysis at point of care, laboratory processing and feedback reporting, reduction of false positives and negatives, and monitoring and evaluation and correcting underperformance.
Best practice must be rooted in an effective disease surveillance system tailored to a country’s health burden, and involving the systematic collection, analysis and dissemination of health data for the planning, implementation and evaluation of interventions.
As rainfall and temperature are key drivers of infectious disease epidemiology, using historical, current and forecast climate information in health decision-making is critical for understanding the shifting habitat ecologies of microbes and preparing responses. Drought has the potential to drive anti-microbial resistance, providing a strong rationale for including climate knowledge in traditional infectious disease training.
The recent Nairobi workshop covered the full range of subjects including infection prevention and control, antimicrobial and diagnostic stewardship, disease surveillance and infectious disease modeling, and climate and weather cycle science.
At a workshop in Mitchells Plain, Cape Town in August — led by health officials Edith Vries and Yasmina Johnson, and the antimicrobial stewardship specialist Adrian Brink — initial feedback data indicated that substantial reductions in antibiotic consumption was possible if it was led by pharmacists focused on evidence-based interventions such as more accurate and careful diagnosis and prescriptions.
There is also a need to assess the impact of alcohol-based hand sanitisers on the survival of new bugs for which there are no antibiotics.
In planning for future droughts, a return to good old-fashioned vigorous hand washing will be necessary.
• James is a visiting professor at the Irving Medical Center and Thomson a senior research scholar at the Mailman School of Public Health — both at Columbia University.