This guest post is by Prof Sally Bloomfield, Chairman, International Scientific Forum on Home Hygiene (IFH)…

At Infection Prevention 2024 in September, I gave a presentation on this issue which I found challenging and thought-provoking to write. I started from the point that environmental hygiene and cleanliness in healthcare settings has 2 fundamentally different functions:

“Hygiene” through practices that reduce risk of exposure of patients, healthcare personnel and visitors to pathogenic microbes	“Visual cleanliness” is vital to sustaining patient, visitor and staff perception that high quality care is being delivered
Physical removal and/or disinfection to reduce microbial contamination on environmental surfaces (and air) to an acceptable (safe) level	Physical removal of dust, soil, etc by mechanical action with or without detergent, until visibly clean

Is hygiene important – yes! – but so is cleanliness – but it’s the elephant in the room. Looking through research papers and healthcare infection prevention, cleaning and hygiene guidelines, this isn’t discussed or explained.

Since 2018, IFH has done a significant amount of polling showing that, although the public are concerned about hygiene, they are confused about the difference between hygiene and cleanliness and it acts as a barrier to practicing effective and sustainable hygiene.  Since cleaning and healthcare professionals move constantly between professional and everyday lives, and formative years are spent in a domestic environment, we need to consider whether this impacts their interpretation of healthcare guidelines.

In 2022 IFH carried out a poll in England to assess what the public understood about hygiene to prevent spread of COVID?

I can become infected with COVID if: (% agree)
Someone coughs or sneezes near me	I touch surfaces touched by others	I touch my nose, mouth, eyes with virus-contaminated hands	COVID-19 virus on my hands can get through my skin and infect me
87%	87%	75 – 85%	31%

This suggests they understood how the SARS-CoV-2 virus that causes COVID-19 spreads, but surprisingly 30% thought it could also penetrate through the skin of their hands! Whilst succinct messaging such as “wash your hands frequently” is memorable, it must also be understandable?

Our follow up looked at when they needed to practice hygiene:

What are important moments to wash/sanitize hands (% agree)
After coughing or sneezing into my hands	After touching surfaces  frequently touched by others	Before eating food with fingers	After handling raw meat and poultry	After using the toilet	After touching pets
90%	86%	89%	84%	90%	56%

Whilst they were able to select important moments, they were almost equally likely to select moments not associated with transmission of respiratory viruses. This suggests a disconnect. They know how COVID-19 spreads but are unable to make reasoned decisions about when to wash hands to prevent spread. It seems probable that they were relying on their memory of “important hygiene habits”.

One thing we are investigating is whether the key to hygiene behaviour change is through developing understanding of the “journey of the germ” and how hygiene practices work, not  just to rid surfaces of harmful microbes, but to  halt that journey and protect us from being exposed. We call this Targeted Hygiene.

A further barrier to practising effective hygiene is misuse of the instruction “Clean—”. Delivering hygiene can be achieved in 2 ways by:

1. Cleaning – i.e physical removal (e.g handwashing, contact surface cleaning and rinsing, machine laundering)
2. Application of disinfectant or heat (e.g hand santizer, surface disinfectant, laundering at elevated temperatures)

But, to deliver hygiene, these processes must be carried out in a prescribed manner which reduces contamination to a level “safe for intended use”, not just “absence of visible dirt”.   In conversation, training etc, we constantly use the instruction “Clean—” when we actually mean “Hygienize”. I recently came across a quote – or maybe a plea – from a cleaning expert saying “If someone asks me to clean a surface…I don’t know what to do unless I know what that surface will be used for.”

In our 2021 study across 25 European countries we asked the public what they understood by these terms:

If correct, it means that, instructed to clean a surface, 15-20% will clean until it looks visibly clean and assume it is also hygienically clean. Additionally, 16-28% will assume that, to make a surface hygienic, it is imperative to use a disinfectant. Since cleaning professionals move between work & home, these misconceptions likely impact on how they interpret healthcare guidelines?

It is easy to dismiss this as trivial, with so many IPC battles to fight. But for environmental cleaning and hygiene, success relies on actions of operators who may have little understanding of the principles of sterilization and “dis-infection”. This sentiment was echoed in paper by Hugo Sax et al., as part of the “crystal ball initiative”, saying “We need to get IPC practice understood by those who need to understand it”.

From this I conclude 2 actions are key:

• Guidelines/training modules etc needto openly address and explain the importance of cleanliness as well as hygiene practices.
• Development of cleaning/hygiene/IPC terminology that is understood by users as well as policy makers