Hand hygiene

Hands are the most common vehicle for spreading infection at work. They touch faces, food, keyboards, door handles, patients, children, tools and each other hundreds of times a day. Cleaning hands at the right moments, with the right product and the right technique, is the single most important infection prevention practice in health care, and one of the cheapest and most effective in every other workplace too.

The idea is not new. In the 1840s, the Hungarian physician Ignaz Semmelweis showed that deaths from childbed fever fell dramatically when doctors cleaned their hands with chlorinated lime between performing autopsies and delivering babies. His colleagues largely rejected the finding, and it took decades, and the germ theory of Pasteur and Lister, for hand hygiene to become standard practice. Even today, studies in hospitals often find that health care workers clean their hands at fewer than half of the moments when they should. The barrier is rarely knowledge; it is habit, workload, access and culture.

Two methods: rub or wash

There are two ways to clean hands. Alcohol-based hand rub (ABHR), usually containing 60 to 90 percent alcohol, kills most bacteria and many viruses quickly, is gentler on skin than repeated washing, and can be placed exactly where work happens. Soap and running water removes dirt, organic material and germs physically; plain soap does not need to be antimicrobial to work, because the rubbing and rinsing remove organisms.

Alcohol-based hand rub works best when enough product is used to keep the hands wet for 20 to 30 seconds while rubbing all surfaces. Too little product dries in a few seconds and misses areas. Hand washing should take 40 to 60 seconds in total, including at least 15 to 20 seconds of lathering and rubbing, followed by thorough rinsing and drying with a single-use towel. Shared cloth towels recontaminate hands. In health care, the towel is used to turn off the tap if taps are not hands-free.

Technique

Germs survive in the places people miss: thumbs, fingertips, between the fingers and the backs of the hands. Studies using fluorescent lotion under ultraviolet light show the same blind spots again and again. A consistent sequence, practiced until it is automatic, covers them.

Rings, watches and long or artificial nails trap germs and make thorough cleaning harder. Many health care employers require bare hands and wrists below the elbow during care, short natural nails and no artificial nails or nail enhancements, because studies have linked artificial nails to outbreaks of serious infections in intensive care units. Outside health care, removing rings and watches during food handling and personal services is a sensible practice.

The moments that matter

Knowing when to clean hands is as important as knowing how. The World Health Organization's "My 5 Moments for Hand Hygiene" model is used around the world in health care. Canada's national approach, promoted by Public Health Ontario and other agencies as "Your 4 Moments for Hand Hygiene", combines two of the WHO moments and is used in many provinces. Both aim at the same thing: cleaning hands before touching a patient or a clean or sterile site, and after contact that may have contaminated them.

Outside health care, the same logic applies to everyday tasks. Clean your hands:

• before eating, preparing food or touching your face, eyes or contact lenses;
• after using the toilet, changing a diaper or helping someone else use the toilet;
• after coughing, sneezing or blowing your nose;
• after handling garbage, cleaning, or touching shared equipment in a busy area;
• before and after first aid or touching a wound;
• after removing gloves;
• when arriving at work and before going home.

Gloves are not a substitute

Gloves protect the wearer's hands from contamination, but they do not replace hand hygiene. Gloves can have tiny holes, hands become contaminated when gloves are taken off, and gloves worn too long carry germs from one surface or person to the next just as bare hands would. Clean your hands before putting on gloves when a clean task follows, change gloves between people and between dirty and clean tasks on the same person, and clean your hands after removing them. Wearing gloves when they are not needed, such as for routine office tasks, wastes supplies and gives a false sense of protection. Lesson 10 covers glove use in more detail.

Skin care

Frequent hand hygiene can damage skin, and damaged skin is both uncomfortable and a risk: cracks and dermatitis hold more bacteria and are portals of entry for bloodborne pathogens. Alcohol-based hand rubs with built-in emollients are usually gentler than repeated washing with soap and hot water. Using lukewarm water, patting hands dry and applying an employer-provided, compatible hand lotion during the shift and after work all help. Some lotions, especially petroleum-based ones, can damage latex gloves or reduce the effect of certain antiseptics, so workplaces should provide products that are known to be compatible. Workers with persistent dermatitis should be assessed by occupational health; it is a recognized occupational skin disease, and it is often caused by irritation from wet work and frequent washing rather than allergy.

Making hand hygiene easy

Hand hygiene compliance rises when the right product is in the right place. Practical steps include:

• hand rub dispensers at entrances, reception desks, break rooms, elevators and, in health care, at the point of care (within arm's reach of where care is given);
• enough sinks with hands-free taps, soap and single-use towels, kept stocked;
• a cleaning and refill schedule with a named person responsible;
• simple visual reminders near dispensers and sinks, refreshed so they do not fade into the background;
• leaders who model the behavior;
• feedback on performance, through audits or electronic monitoring, shared in a supportive rather than punitive way.

Alcohol-based hand rub is flammable. Fire codes allow dispensers in corridors and rooms, but limit their size and spacing and keep them away from ignition sources such as electrical outlets and switches. Supplies in bulk storage must be kept according to the fire code, and the product's safety data sheet describes hazards. Some settings, such as mental health units, correctional facilities and schools, choose products or dispenser types that reduce the risk of people drinking hand rub.

Measuring hand hygiene

Hospitals and long-term care homes often audit hand hygiene by direct observation: a trained auditor watches care for a set period and records whether each opportunity (each moment that called for hand hygiene) was met. Compliance is the number of opportunities met divided by the number observed. Because staff behave better when they know they are watched (the Hawthorne effect), observed rates usually overestimate true compliance. Electronic systems that count dispenser use, and covert or rotating auditors, help reduce this bias.

A small number of observations gives an uncertain estimate. Reporting a confidence interval, not just a single percentage, shows how much the result could vary by chance. The Wilson score interval works well for proportions, especially with small samples.

import math

def wilson(met, n, z=1.96):
    p = met / n
    mid = (p + z * z / (2 * n)) / (1 + z * z / n)
    half = z * math.sqrt(p * (1 - p) / n + z * z / (4 * n * n)) / (1 + z * z / n)
    return mid - half, mid + half

# Hand hygiene audits on two units (opportunities met, opportunities observed)
for unit, met, n in [("Unit A", 41, 60), ("Unit B", 168, 240)]:
    lo, hi = wilson(met, n)
    print(f"{unit}: {met}/{n} = {met / n:.0%}, 95% interval {lo:.0%} to {hi:.0%}")

Unit A: 41/60 = 68%, 95% interval 56% to 79%
Unit B: 168/240 = 70%, 95% interval 64% to 75%

Unit A and Unit B have similar compliance, but Unit A's interval is much wider because it is based on far fewer observations. A manager should not conclude that Unit A is worse, or that a small change from one month to the next is real, without enough data. The same logic applies to any audit with a pass or fail result, from cleaning checks to protective equipment use.

Hand hygiene for the public

In workplaces open to the public, such as stores, offices, transit, gyms and schools, hand rub at entrances and in high-traffic areas encourages customers and visitors to clean their hands too. Schools that teach and schedule hand washing for children, before eating and after recess and the toilet, see fewer absences from gastrointestinal and respiratory illness. Child care staff should supervise and help young children wash their hands and wash their own after every diaper change.