Infection hazards for workers

Infection control in hospitals is usually discussed as a way of protecting patients, and it is. But the same germs that spread from patient to patient also spread from patients to staff, and from staff to their families. Healthcare workers have caught tuberculosis, influenza, norovirus, hepatitis B, COVID-19 and many other infections at work, and some have died of them. This lesson looks at infection as a hazard to workers. HSE-245 Infection Prevention and Control covers the subject in depth, HSE-240 Respiratory Protection covers N95 respirators and fit testing, and HSE-392 covers sharps and bloodborne pathogens. Here the focus is on what every worker in a hospital, a care home or a client's home needs to know and do.

Nothing in this lesson is medical advice. Questions about your own vaccinations, symptoms, exposures or treatment belong with the hospital's occupational health nurse or your own doctor.

The chain of infection

For an infection to spread, six links have to connect. Break any one of them and the chain is broken.

• The infectious agent: the bacterium, virus, fungus or parasite.
• The reservoir: where it lives, such as an infected patient, a contaminated surface, standing water or a piece of equipment.
• The portal of exit: how it leaves the reservoir, such as a cough, blood, stool or a wound.
• The mode of transmission: how it travels to the next person.
• The portal of entry: how it gets in, such as the mouth, nose, eyes, broken skin or a needlestick.
• The susceptible host: a person who can be infected, which includes every worker who is not immune.

Most of what workers do to protect themselves targets the middle links. Hand hygiene and cleaning break the contact route. Masks, respirators and eye protection block portals of entry. Safety-engineered sharps prevent the most direct route of all. Vaccination makes the host less susceptible.

How infections reach workers

Some groups of workers face particular routes. Environmental services staff and laundry workers handle contaminated linen, waste and surfaces many times a day. Transporters spend minutes at a time beside patients in elevators and corridors, often before anyone knows what infection the patient has. Lab staff handle specimens of blood, stool, sputum and tissue. Home health staff work in homes where the usual hospital controls, such as isolation rooms and ventilation, do not exist.

Standard precautions for every patient

Because staff cannot know which patients are infectious, the basic protections are used with everyone. In the United States these are called standard precautions, based on CDC guidance. They include:

• Hand hygiene at the right moments: before touching a patient or their surroundings, before a clean or aseptic procedure, after a risk of exposure to body fluids, and after touching a patient or their surroundings. Alcohol-based hand rub is the default; soap and water are used when hands are visibly soiled and for some infections, such as C. difficile and norovirus, that alcohol does not kill well.
• A risk assessment before each interaction, as described in Lesson 3, to decide what protection is needed.
• Personal protective equipment for the exposure you expect: gloves when touching blood, body fluids, broken skin or contaminated items; a gown when clothing could be soiled; a mask and eye protection when splashes or sprays are likely.
• Respiratory etiquette: covering coughs, offering masks to coughing patients and visitors.
• Safe handling and disposal of sharps.
• Cleaning and disinfection of equipment and the environment.
• Safe handling of linen and waste.

When a patient is known or suspected to have an infection that spreads in a particular way, transmission-based precautions are added: contact precautions (gloves and gown), droplet precautions (mask and eye protection), or airborne precautions (an N95 respirator and an airborne infection isolation room). A sign on the door tells staff which ones apply, and an isolation cart outside the room holds the supplies. Nursing homes also use enhanced barrier precautions, gowns and gloves for high-contact care of residents with certain wounds, devices or drug-resistant organisms.

Putting on and taking off PPE

Protective equipment protects you only if it is put on in an order that leaves no gaps and taken off in an order that does not contaminate you. Taking it off is the risky part, because the outside of the gloves and gown is now contaminated.

Amira's tips for taking PPE off are the ones the infection control team teaches. Take it off slowly. Touch the outside only with gloved hands and the inside only with bare hands. Roll the gown inside out as it comes off. Remove eye protection and masks by the straps or ear loops, never by the front. Clean your hands whenever you think they might be contaminated, not only at the end. And for airborne precautions, take off the respirator after leaving the room and closing the door.

N95 respirators

An N95 respirator protects only if it seals to the face, which is why every worker who may need one must be fit tested with the exact make, model and size they will use, and trained to do a seal check each time they put it on. OSHA's Respiratory Protection standard (29 CFR 1910.134) requires a written program, a medical evaluation, fit testing before first use and at least once a year after that, and training. Northbridge tests every clinical worker, transporter and environmental services worker who may enter an airborne isolation room. HSE-240 covers respirators in depth.

Vaccination and immunity

Vaccination protects workers and, by preventing staff from passing infections on, their patients. The Bloodborne Pathogens standard requires employers to offer the hepatitis B vaccine, at no cost, to every worker with occupational exposure to blood, within 10 working days of starting the job, and a worker who declines must sign a declination and can change their mind later. Northbridge's employee health office also checks each new worker's immunity to measles, mumps, rubella and chickenpox, offers the vaccines that are recommended for healthcare workers, screens new staff for tuberculosis, and runs a yearly influenza and COVID-19 vaccination clinic. The details of what each worker needs are a matter for employee health, not the unit.

Coming to work sick

One of the most common ways infections spread in hospitals is through staff who come to work ill. Healthcare workers do it because they do not want to leave the unit short, because they feel guilty, or because they cannot afford to lose the pay. An outbreak of norovirus or influenza on a unit can sicken dozens of patients and staff and close beds for weeks. Northbridge's rule is that staff with symptoms of a contagious illness, such as fever, vomiting, diarrhea or a new cough, report to occupational health or their manager before the shift and stay home until they are cleared. A rule like this only works if staffing and sick pay make it realistic to follow.

For supervisors: the isolation cart

The most common reason staff go into an isolation room without the right protection is that the right protection is not there. Check isolation carts at every shift change: gowns, gloves in every size, masks, eye protection, the right N95 models and sizes for the staff on shift, hand rub and a waste container. Know which of your staff are fit tested and for which models. When supplies run short, tell your manager and the infection control team at once, and never let a shortage become an unspoken reason to skip protection.

Exposures and what to do

An exposure happens when a worker has contact with an infection in a way that could transmit it: a needlestick, a splash of blood in the eye, caring for a patient with tuberculosis before anyone knew, or feeding a resident who turns out to have norovirus. The worker should report it to their supervisor and occupational health right away, because for some exposures, especially needlesticks and blood splashes, follow-up is time-sensitive and should begin within hours. Lesson 11 covers reporting, and HSE-392 covers bloodborne exposures in detail.

Joanne tracks every exposure report and how quickly it was made.

# Infection-related exposure reports at Northbridge last year:
# (type, hours from exposure to report)
exposures = [
    ("needlestick", 0.5), ("needlestick", 1), ("needlestick", 0.3), ("needlestick", 6),
    ("needlestick", 0.8), ("needlestick", 26), ("needlestick", 1.5), ("needlestick", 0.4),
    ("needlestick", 2), ("needlestick", 0.6), ("needlestick", 1.2), ("needlestick", 0.5),
    ("blood splash", 0.7), ("blood splash", 3), ("blood splash", 0.5), ("blood splash", 12),
    ("TB contact", 48), ("TB contact", 48), ("TB contact", 48), ("TB contact", 50),
    ("norovirus", 24), ("norovirus", 30),
    ("scabies", 72), ("scabies", 72), ("measles contact", 20),
]
types = {}
for t, h in exposures:
    types.setdefault(t, []).append(h)

print(f"{'type':16}{'count':>6}{'median hours':>14}{'within 2 h':>12}")
for t, hs in sorted(types.items(), key=lambda kv: -len(kv[1])):
    hs = sorted(hs)
    n = len(hs)
    median = hs[n // 2] if n % 2 else (hs[n // 2 - 1] + hs[n // 2]) / 2
    fast = sum(1 for h in hs if h <= 2)
    print(f"{t:16}{n:6}{median:14.1f}{fast:9} of {n}")

blood = types["needlestick"] + types["blood splash"]
late = [h for h in blood if h > 2]
print(f"\nblood exposures reported after 2 hours: {len(late)} of {len(blood)}")

type             count  median hours  within 2 h
needlestick         12           0.9       10 of 12
blood splash         4           1.9        2 of 4
TB contact           4          48.0        0 of 4
norovirus            2          27.0        0 of 2
scabies              2          72.0        0 of 2
measles contact      1          20.0        0 of 1

blood exposures reported after 2 hours: 4 of 16

Most needlesticks are reported within an hour, which is good. Four of the 16 blood exposures were reported more than two hours later, including one needlestick reported the next day, which is too slow for the follow-up to work as intended. The tuberculosis and scabies contacts are reported late for a different reason: nobody knew the patient was infectious until test results came back, and occupational health then traced the staff who had been in contact. Those delays cannot be fixed by telling staff to report faster. They are fixed by faster recognition and isolation of patients with symptoms, which is why the emergency department screens for cough and fever at triage.