Microbiology π¦ Flashcards
what is the definition of HAIs?
HAIs are infections acquired in a hospital (or healthcare facility) 48 hours or more after admission.
what were HAIs previously refered as?
were previously referred to as βnosocomialβ or βhospital infectionsβ.
where could HAIs occur?
may occur in patients, visitors, or healthcare members (staff & workers)
what causes HAIs?
can be caused by any microbial agent: bacteria, virus, fungus, or parasite
what are the types of HAIs?
- Central line-associated blood stream infections (CLABSI)
- Catheter-associated urinary tract infections (CAUTI)
- Ventilator-associated pneumonia (VAP)
- Surgical site infections (SSI)
- Others e.g., C. difficile infections
what are the sources of HAIs?
Endogenous source:
- from patientβs own flora of the skin, gastrointestinal, respiratory, or genitourinary tract.
Exogenous source:
- Animate source:
a) Medical personnel.
b) Patients.
- Inanimate source:
a) Hospital environment : air, dust, water.
b) Patient care equipment and medical devices : such as intravenous (IV) fluids and catheters, ventilators & respiratory equipment, endoscopes, disinfectants, and bedpans.
what is the mode of transmission of HAIs?
1. Contact transmission: e.g., MRSA & Clostridium difficile.
- Direct contact with an infected person .
- Indirect contact with contaminated surfaces (touched by the infected person, or where droplets or body fluid settled).
- Hands are the most important vehicle for transmission of healthcare- associated infections
2. Respiratory (Airborne) transmission: e.g., T.B, Measles & Varicella.
- Aerosols (i.e., particles < 5ΞΌm in size) remain suspended in air for long time and widely spread organisms by air currents.
3. Droplet transmission: e.g, Influenza & Mumps.
- Droplets (i.e., particles > 5ΞΌm in size) travel for short distance through air, and organisms are deposited on mucosa of mouth, conjunctiva, or nose.
4. Common vehicle transmission:
- Contaminated items such as food, water, devices, and medication transmit organisms to host.
5. Vector borne transmission:
- Vectors such as mosquitoes, flies, rats, and other pests transmit organisms to host.
what are the factors affecting HAIs?
1. Microbial factors:
- Microbial virulence.
- Microbial dose.
- Microbial resistance.
- Higher microbial virulence, dose and resistance increase the risk of HAI.
2. Patient susceptibility:
- Age : infants & old age patients are more susceptible to infection.
- Immune status : immune-compromised patients are more susceptible to infection.
- Prolonged hospital stay.
3. Environmental factors:
- Hospitals house large number of sick & immune-compromised people.
- Medical procedures bypass bodyβs natural protective barriers.
- Wide use of antibiotics in hospitals leads to emergence of resistant strains.
- Medical staff move from patient to patient, so may help spread of pathogens.
what is the definition of HAIs Prevention & control precautions?
These are measures practiced by healthcare workers (HCWs) to prevent transmission of infection among patients and healthcare workers.
what do HAIs Prevention & control precautions include?
They include :
1- Standard precautions
2- Transmission-basedprecautions
3- HCWs vaccination
what are the standard HAIs Prevention & control precautions?
- As defined by CDC : standard precautions are set of practices designed to prevent the transmission of HIV, Hepatitis B virus & other blood borne pathogens (bacteria & viruses).
- Blood and other body fluids of all patients should be considered potentially infectious.
- These practices should be done for care of all patients all times.
what are the elements of standard precautions?
- Hand Hygiene
- Personal protective equipment (PPE)
- Safe injection practices
- Sharps injury prevention
- Respiratory hygiene/cough etiquette
- Cleaning of care equipment between patients
- Textiles and laundry
- Care of environment
- Safe waste disposal
what is the single most effective precaution for prevention of infection among patients & healthcare staff?
- Hand hygiene is the single most effective precaution for prevention of infection among patients & healthcare staff.
β Types of hand hygiene.
β Hand washing technique.
β When to wash your hands?
what is PPE?
- PPE are specialized clothing or equipment worn by an employee for protection against infectious materials.
They include:
a) Gloves
b) Masks & protective eye wear
c) Gowns/Aprons
Safe injection practices
- Use aseptic technique .
- Use syringe, needle, and fluid infusion set only once.
- Use single-dose vials when possible.
- Use and store multi-dose vials according to manufacturer recommendations.
Sharps injury prevention
what is Respiratory hygiene/cough etiquette used for?
Respiratory hygiene/cough etiquette
Cleaning of care equipment between patients
Textiles and laundry
Care of environment
Safe waste disposal
what are Transmission-Based Precautions?
are used for patients with known or suspected infections, or for patients at risk of acquiring
infection from others.
what do Transmission-Based Precautions include?
They include :
a) Air borne precautions
b) Droplet precautions
c) Contact precautions
d) Environment (Protective) precautions
HCW vaccination for hepatitis B
Criteria:
- No past completion of vaccine series
- No serologic evidence of immunity
Regimen:
- Three doses: second dose 1 month after first dose, third dose 5 months after second dose
- serologic testing after completion
HCW vaccination for Influenza
criteria:
- Recommended annually
Regimen:
- single dose annually
HCW vaccination for MMR
criteria:
- Born in 1957 or later and no past immunization, No serologic evidence of immunity
- Born before 1957 is considered evidence of immunity
Regimen:
- If not immune to measles/mumps, give two doses 28 days apart
- If not immune to rubella, Give single dose
HCW vaccination for Varicella
criteria:
- No past completion of vaccine series
- No serologic evidence of immunity
- No past infection
Regimen:
- Two doses 4 weeks apart
HCW vaccination for Tetanus, Diptheria & pertussus (Tdap)
HCW vaccination for Meningococcal
Criteria:
- Routine exposure to neiseria meningtidis
Regimen:
- Single dose
Post HBV vaccination serologic testing
- serologic testing for HCW is done after completion of vaccination to test HCWβs response to vaccine.
what are types of exposure to Blood-Borne pathogens (BBPS)?
1- Percutaneous exposure through sharps injury.
2- Muco-cutaneous exposure through splash or blood or body fluids into mucous membranes.
what is the risk of exposure to Blood-Borne pathogens (BBPS)?
the transmission of blood-borne pathogens (BBPs) including Hepatitis B virus (HBV), Hepatitis C virus (HCV), Human immunodeficiency virus (HIV) are:
- HBV: risk is up to 30%
- HCV: risk is up to 3%
- HIV: risk is up to 0.3%
Management ofexposure of HCW to blood-borne pathogens (BBPs)
First aid measures:
1- Encourage gentle bleeding, do not suck.
2- Wash the skin with soap and water, do not scrub.
3- Irrigate contaminated mucous membranes with large amount of water.
4- Cover the injury with dressing and seek medical advice without delay.
5- Report to the supervisor and the infection control team.
Post-exposure prophylaxis (PEP) of HCW:
1- Against HBV exposure.
2- Against HCV exposure
3- Against HIV exposure
Recommendations for post-exposure prophylaxis of HCW against HBV infection
Recommendations for post-exposure prophylaxis of HCW against HCV infection
Recommendations for PEP of HCW against HIV infection
