17-Healthcare Epidemiology

Healthcare epidemiology

can be defined as the study of the occurrence, determinants, and distribution of health and disease within healthcare settings.

(a) healthcare-associated infections or HAIs

(b) community-acquired infections

Infectious diseases (infections) can be divided into two categories depending on where the person became infected:

healthcare-associated infections or HAIs

infections that are acquired within hospitals or other healthcare facilities

community-acquired infections

infections that are acquired outside of healthcare facilities

iatrogenic infection

“physician-induced”

is an infection that results from medical or surgical treatment — an infection that is caused by a surgeon, another physician, or some other healthcare worker.

1. Gram-positive cocci

2. Gram-negative bacilli

most common causes of HAIs in the United States:

Gram-positive cocci

Staphylococcus aureus (including methicillin-resistant strains of Staphylococcus aureus [MRSA])

Coagulase-negative staphylococci

Enterococcus spp. (including vancomycin-resistant enterococci)

Gram-negative bacilli

Escherichia coli

Pseudomonas aeruginosa

Enterobacter spp.

Klebsiella spp.

Urinary catheters

provide a “superhighway” for indigenous microflora of the distal urethra to gain access to the urinary bladder.

C. difficile

is a common cause of healthcare- associated gastrointestinal infections.

is an anaerobic, spore-forming, Gram-positive bacillus. It is a common member of the indigenous microflora of the colon, where it exists in relatively small numbers.

which is resistant to many orally administered antibiotics, then increases in number, leading to increased concentrations of the toxins.

immunosuppressed patients

patients whose immune systems have been weakened by age, underlying diseases, or medical or surgical treatments.

Handwashing

is the single most important measure to reduce the risks of transmitting pathogens from one patient to another or from one anatomic site to another on the same patient.

asepsis

blood without bacteria

sepsis

blood with bacteria

1. Medical Asepsis

2. Surgical Asepsis

two types of asepsis in healthcare setting

Medical Asepsis

is a clean technique. Its goal is to exclude pathogens.

includes all the precautionary measures necessary to prevent direct transfer of pathogens from per- son to person and indirect transfer of pathogens through the air or on instruments, bedding, equipment, and other inanimate objects (fomites).

Disinfection

the process of removing micro-organisms, including potentially pathogenic ones, from the surfaces of inanimate objects

chemical sterilant

A few disinfectants will kill bacterial spores with prolonged exposure times

High-level disinfectants

kill all microbes (including viruses),e except large numbers of bacterial spores.

Intermediate-level disinfectants

might kill mycobacteria, vegetative bacteria, most viruses, and most fungi, but do not necessarily kill bacterial spores.

Low-level disinfectants

kill most vegetative bacteria, some fungi, and some viruses within 10 minutes of expo- sure.

Standard Precautions

will protect both healthcare personnel and their patients from becoming infected with HIV, HBV, HCV, and many other pathogens.

Vaccinations

Because healthcare personnel are at particular risk for several vaccine-preventable infectious diseases,

• Hepatitis B recombinant vaccine

• Influenza vaccine

• Measles live-virus vaccine

• Mumps live-virus vaccine

• Rubella live-virus vaccine

• Varicella-zoster live-virus vaccine

Hand Hygiene or Hand Washing

The most important and most basic technique in preventing and controlling infections and preventing the transmission of pathogens is

plain (nonantimicrobial) soap

may be used for routine handwashing,

antimicrobial or antiseptic agent

should be used in certain circumstances (e.g., before entering an operating room or to control outbreaks within the hospital)

alcohol-based hand-rubs

that do not require the use of water can be used in place of handwashing when hands are not visibly soiled.

1. Gloves.

2. Isolation Gowns.

3. Masks.

4. Eye Protection.

5. Respiratory Protection.

Personal Protective Equipment

Gloves.

can protect both patients and healthcare personnel from exposure to infectious materials that may be carried on hands.

must be changed be- tween tasks and procedures on the same patient whenever there is risk of transferring mi- croorganisms from one body site to another.

Isolation Gowns.

are worn in conjunction with gloves and with other PPE when indicated. ____ are usually the first piece of PPE to be donned. They protect the healthcare worker’s arms and exposed body areas and prevent contamination of clothing with blood, body fluids, and other potentially infectious material.

When applying Standard Precautions, an ____________ is worn only if contact with blood or body fluid is anticipated.

Masks.

They are worn by healthcare personnel to protect them from contact with infectious material from patients.

They are worn by healthcare personnel when engaged in procedures requiring sterile technique to protect patients from exposure to pathogens that may be present in a healthcare worker’s mouth or nose.

They are placed on coughing patients to limit potential dissemination of infectious respiratory secretions from the patient to others.

Eye Protection.

include goggles and disposable or non-disposable face shields. _________________ may be used in combination with goggles, or a face shield may be used instead of a mask and goggles. Even when Droplet Precautions are not indicated, eye, nose, and mouth protection are necessary when it is likely that there will be a splash or spray of any respiratory secretions or other body fluids.

Respiratory Protection.

requires the use of a respirator with N95 of higher filtration to prevent inhalation of infectious particles (Fig. 12-6).g Do not confuse masks with particulate respirators.

Linens

Textiles such as bedding, towels, and patient gowns that have become soiled with blood, body fluids, secretions, or excretions must be handled, transported, and laundered in a safe manner. Soiled textiles must not be shaken, must not come in contact with the healthcare worker’s body or clothing, and must be contained in a laundry bag or designated bin.

Disposal of Sharps

Needlestick injuries and injuries resulting from broken glass and other sharps are the primary manner in which healthcare workers become infected with pathogens such as HIV, HBV, and HCV. Thus, Standard Precautions include guidelines regarding the safe handling of such items. Needles and other sharp devices must be handled in a manner that prevents injury to the user and to others who may encounter the device during or after a procedure.

Protective Environments

are rooms that are under positive pressure, and vented air that enters these rooms passes through HEPA filters.

immunosuppressed persons, those receiving radiation treatments, leukopenic patients (those having abnormally low white blood cell counts), and premature infants.

Infection Control Committee

is composed of representatives from most of the hospital’s departments, including medical and surgical services, pathology, nursing, hospital administration, risk management, pharmacy, housekeeping, food services, and central supply.

Infection Control Professional

such as a physician (e.g., an epidemiologist or infectious disease specialist), an infection control nurse, a microbiologist, or some other person knowledgeable about infection control.