Superbugs Are Now ‘More Tolerant’ to Hand Wash and Sanitizers, Study Reveals


Back in the early 2000s, hospitals all across the world began installing more and more sanitizers and hand wash dispensers to be used by the staff, patients and all the visitors. Research has already showed that these alcohol-based sanitizers effectively inhibit staph infections in the patients and also kill certain other types of drug-resistant bacteria. And, eventually the rates of these common infections went down.

But, certain other infections remain unaffected when people started using these hand washes and sanitizers. In fact, these infections became more prevalent over time. Particularly, enterococcal infections – caused by the bacteria, affecting the bladder, digestive tract, heart and other parts of the body – started increasing rapidly.

This became the case in nearly all the countries around the world and they experienced similar surge in these types of infection even after hand sanitizers became quite popular. [1] Globally, enterococci infections make 10% of the bacterial infections that are acquired in the hospital. In Europe and North America, they even lead to sepsis, which is a life-threatening blood infection. Now, scientists believe that they have found the underlying cause and it is probably due to alcohol.

What Does the Study Reveal about The Antibiotic Resistant Bacteria?

A new research, published in the Science Translational Medicine, reveals that certain strains of these bacteria have started being resistant to the alcohol-based sanitizers.[2] However, it is not that they have developed complete resistance to alcohol, but they are becoming increasingly “more tolerant” to it, according to the study authors. This means the bacteria are able to survive for longer periods of time after being doused with alcohol.
The scientists used various alcohol concentrations of different strengths to effectively inhibit the bacteria, starting with the 23% concentration. Eventually, when they used 70% alcohol mixture, the bacteria were effectively conquered. Generally, hand sanitizers use 60% alcohol.[3]


To make things worse, most of these alcohol-tolerant superbugs are also resistant to various drugs too. Almost half of these strains could not be treated with vancomycin, which is a last-line antibiotic. This indicates that these superbugs are spreading more rapidly within hospitals, and they cannot be treated as easily as we think.
The study authors were also surprised by the findings of this study.

what does the study reveal about the antibiotic resistant bacteria

Timothy Stinear, the study author and researcher, explained that this is the first time anyone has observed that the hospital bacteria has become tolerant to the alcohols.
The researchers first compared 139 kinds of bacteria, analyzing the same strains over a 19-year duration from the year 1997 to 2015. As the time passed, these bacteria somehow evolved and developed tolerance to alcohol. To be precise, bacteria that was collected after the year 2009 were almost 10 times more tolerant than those collected before 2004. This also corresponds to the increasing national push to use hand sanitizers frequently.

But, in reality, the bacteria don’t operate similarly in your body as they do in a laboratory. It is in fact quite risky to study these drug-resistant bacteria on humans, so the researchers conducted these tests on mice, which also generally is closest to knowing how humans would react. The results were almost similar; the guts of the model mice showcased the signs of the alcohol-tolerant superbugs even when the cages were thoroughly cleaned with an alcohol solution.

The health care industry is however trying to inhibit the spread of these superbugs by adhering rigorously to the predefined hand hygiene protocols. Stinear further stated that health care institutes must take additional measures to prevent the spread through hand washing using a soap after a person comes in contact with any kind of bacteria.

what does the study reveal about the antibiotic resistant bacteria

Lance Price, professor, the George Washington University’s Milken Institute School of Public Health, was equally surprised by these findings.Price asserted that evolution of these bacteria happens quite quickly as he and his team are actually dealing with the populations that can easily double every half an hour and possibly travel in numbers as large as billions.

Enterococci is most commonly found bacteria in the hospitals. This study has major implications for any other type of bacteria that might become tolerant to alcohol. For example, organisms, such as C. diff, which is another rapidly spreading infection have hard shells that can make it really difficult for the alcohol to surpass them. The best way, hence, is to wash them with water down the drain.

Price explains that if you scarcely wash your hands believing that alcohol-based hand sanitizers can completely clean your hands, you will probably become a safe haven for alcohol-resistant bacteria.

The research has clearly indicated that the alcohol-based sanitizers are much more effective at inhibiting certain bacteria like the ones that cause staph infections. However, this particular study revealed that most other bacteria are best inhibited by using a simple soap and water.

Price emphasizes that all of us must be more careful about using alcohol-based sanitizers. He asserts that a simple soap and water are still our number one protection against these bacteria. And, this holds true for both hospital and personal use.

Other major concerns of the researchers is that whether these bacteria will go on to evolve and become tolerant to higher and higher concentrations of alcohol or they will ever stop responding completely to alcohol.


Thus, it’s time to get back to washing hands using soap and water, and avoid relying completely on alcohol-based sanitizers to keep bacterial infections at bay.