Bacterial Infection and Hand Hygiene

Study Notes

Hands are a source of infection
The entire human body is colonized by microorganisms
Skin below the waist, especially the moist perineal and inguinal regions, has a high concentration of microorganisms
People shed approximately one million skin scales (squames) per day
Microorganisms are attached to these shed skin scales
Staphylococci and enterococci are commonly shed bacteria found on clothes, uniforms, masks and the surrounding environment

Two types of bacteria are present on the skin of the hands: resident and transient
Resident bacteria: Gram-positive, low virulence, difficult to transmit via hand contact, and hard to remove with hand hygiene
Transient bacteria: Gram-negative, significant causes of nosocomial infections, and easily removed with hand hygiene
Resident bacteria form the persistent flora of hands and live on the skin's surface without causing infection
If the skin's integrity is compromised, resident bacteria can become opportunistic pathogens, causing wound or deep-seated infections. Staphylococcus epidermidis is an example.

Contact with surfaces or individuals can transfer hundreds to thousands of bacteria onto the hands, which then easily infect the next person contacted.

5-10% of patients in hospitals develop HCAIs during their stay at the hospital
These infections result in 2 million patients becoming infected
80,000 deaths per year are attributed to infections in hospitals
600,000 healthcare-associated infections (HCAIs) are caused by staff who do not wash their hands after treating each patient.

The World Health Organization (WHO) recommends five key moments for hand hygiene
These moments are based on the evidence of how microbes are transmitted:
- Before touching a patient
- Before clean/aseptic procedures
- After body fluid exposure (e.g., saliva, blood)
- After touching a patient
- After touching patient surroundings

Traditional hand washing with soap is a method of hygiene
Antiseptic hand washes are also a method of hygiene
Alcohol-based hand rubs are also a method of hygiene
Not all hand hygiene methods are equally effective
The choice of method depends on the reason for cleaning the hands, which includes:
- Visibly clean hands
- Soiled hands (e.g., with blood and dirt)
Alcohol-based hand rubs are effective against Gram-negative and Gram-positive bacteria (like MRSA, and vancomycin-resistant Enterococci)
The active ingredient in alcohol-based hand rubs is an alcoholic solution, typically ranging from 65-70%

Alcohol-based hand rubs are only effective on visibly clean hands
Alcohol-based hand rubs are ineffective against Clostridium difficile, which produces spores and watery diarrhea.
Alcohol evaporates rapidly, limiting its effectiveness
Long-term repetitive use can lead to alterations in the thyroid and reproductive systems of neonates and adolescents as well as the detection of alcohol in the bloodstream.

Removing rings and watches is crucial for effective hand hygiene.
Surgical procedures demand more extensive disinfection, known as antisepsis.
A surgical scrub is required to diminish resident bacteria.
Surgical scrub technique is focused on washing from a clean area (e.g., upper arm) to a less clean area (e.g., hands).
Using a timed scrub is one technique.
A numbered stroke method is another technique.
Cleaning fingernails, under fingernails, between fingers, and around wrists is crucial.
Using sterile towels, using a dabbing motion, and keeping arms elevated prevents contamination of the hands by the antiseptic.
The scrub process needs to be repeated three times starting again from the hands toward the wrists.

Posters must be visible to display procedures for hand hygiene in surgeries
Cuts and abrasions must be covered with bandages to avoid infection or cross-contamination
Fingernails must be short and clean, and artificial nails should be avoided.
Jewelry, including most rings, should be removed before procedures
Hand creams should be used regularly to prevent dry skin but avoid shared hand creams.
Washing hands is crucial to avoid infection in healthcare settings.
Alcohol-based hand rubs are useful, but they aren't as effective against all germs.
Proper hand hygiene technique must be observed to minimize contamination.