Increased hand sanitizer use blamed for rise in gastro outbreaks

A number of countries are reporting increasing rates of viral gastroenteritis over recent months, and experts suggest greater use of hand sanitizers, known to have little effect on pathogens such as norovirus, may be partly responsible.

New data released by health authorities in the Australian state of Victoria is reporting a four-fold increase in gastroenteritis outbreaks across childcare facilities over the first few months of 2021, compared to the five-year average. Other countries such as New Zealand and Taiwan have also reported spikes in norovirus outbreaks over recent months.

Gastroenteritis is commonly caused by a virus called norovirus. It is known to be spread by touching one’s mouth after coming into contact with a contaminated surface or person. Parents of small children are certainly familiar with the illness as the virus is often spread by children, and child-care facilities are notorious hotbeds for clusters of infection.

“Norovirus causes vomiting and diarrhea,” explains Cathy Moir, chair of Australia’s Food Safety Information Council. “Cases occur all year round but they peak during winter possibly because that is when we tend to be in closer contact indoors allowing the virus to easily spread. Norovirus outbreaks are also common where people are in close living spaces, such as aged-care and child-care facilities, hospitals, cruise ships and community sporting events.”

Exactly why norovirus clusters seem to be increasing is unclear, but some experts are suggesting the growth in use of alcohol-based hand sanitizers may be playing a role. As the COVID-19 pandemic took hold in early 2020 more people than ever started frequently using hand sanitizers. Some estimates suggested demand for the product grew 16-fold in the first few months of the pandemic.

“I suspect many of us have become a bit complacent with handwashing and instead are slapping on alcohol-based hand sanitizer when we can, although this is anecdotal,” hypothesizes gastroenterologist Vincent Ho, in a recent article for The Conversation. “However, even though hand sanitizer is convenient, it doesn’t work as well against norovirus as thorough handwashing does.”

Researchers have long suspected alcohol-based hand sanitizers may not be as effective as soap and water handwashing in removing norovirus. A compelling 2011 survey of 161 long-term care facilities in the United States found those facilities using soap and water more often than hand sanitizers experienced less frequent norovirus outbreaks.

Peter Collignon, an infectious disease specialist from Australian National University, suggests hand sanitizers do not remove contaminants from soiled hands. He recommends people should not replace thorough hand washing with hand sanitizers, but instead says we should think about cleaning our hands before sterilizing them with alcohol-based solutions.

“Like all disinfecting, cleaning first is essential,” says Collignon. “You can’t just dip something in a magic solution and make it sterile. Clean, then sterilize. Gastro is one of those examples of sanitizer not working quickly and taking a while to penetrate, so handwashing is important.”