Healthcare associated infections Flashcards
what is a healthcare associated infection
Healthcare Associated Infection -HAI- (Nosocomial infection) is one that is not present or incubating when a patient is admitted to hospital.
who is it a major problem for (2 people)
patients- but also staff
what is the US data
4% of all admissions and rates increasing
Prolonged stays by 4-13 days.
20-35 Billion Dollars
687,000 cases and 72,000 deaths 2015
what is the cost to the NHS in England and Wales
£2 bn+ in costs annually
20K annual deaths of patients with HAI
What are the European HAI levels
4,000,000 get a HAI annually
37,000 fatalities
what are the % of admissions in developed countries
5-10
what are the % of admissions in developing countries
10-30
how likely are the patients to die
Patients with nosocomial infection are 7.1 times more likely to die
how long do they stay in hospital
Patients with an infection remain in hospital on average 2.5 times longer than other patients
-average additional length of stay is 11 days
-Increased cost and Increased risk
where do the disease rates vary
-vary between countries, within a country, between hospitals and even within a hospital
-Different mixtures of patients (geriatric v maternity)
-Differing treatments (cancer v orthopaedic)
-Differing policies
what are the 2 classes for HAI
Endogenous and exogenous
explain endogenous
-Organism is part of the normal microbiota of the patient.
-Acts as an opportunistic pathogen
-Underlying health issues for patient= Innate immunity compromised
-Medical interventions on patient= Innate immunity compromised
Explain a exogenous infection
Organism comes from other patients, hospital personnel, equipment or environment= Can be an opportunistic pathogen or a true pathogen
how do exogenous pathogens spread
-direct contact= Staff-patient, patient-patient and visitors may also have a role but more difficult to prove.
-fomites= Medical and other devices passed between patients
-air
-water
What are the risk factors for HAI in Nursing homes
-Compromised patients
-Infected patients as reservoirs of infection
-Crowding predisposes to infection
-Interaction of individual staff with many patients
what are the risk factors of HAI in newbornes
Newborns at risk due to immature immune systems
what are the general risk factors for HAI (procedures and control)
-Many procedures can overcome the innate host defence mechanisms= Surgery, Immunosuppression, Injection, Catheterisation and Biopsy
-Control of infection by antibiotics can predispose to superinfection by yeasts and other exotic microorganisms.
what are CAUTIs
Catheter-associated urinary tract infections- A urinary tract infection (UTI) is an infection involving any part of the urinary system, including urethra, bladder, ureters, and kidney
what are the main groups for HAIs
-Urinary tract infections= Catheter-associated Urinary Tract Infections
-Surgical wound infections=12%
-Lower respiratory infections= Ventilator-associated Pneumonia and VAP
-Septicaemia= Central line associated Bloodstream Infections (CLABSIs)
what is Ventilation associated pneumonia
pneumonia occurring more than 48 h after patients have been intubated and received mechanical ventilation
what are central lines
intravascular catheter that terminates at or close to the heart or in one of the GREAT VESSELS which is used for infusion, blood withdrawal or hemodynamic monitoring
what are some of the great vessels
Aorta
Pulmonary arteries
Superior vena cava
Inferior vena cava
Brachiocephalic veins
Internal jugular veins
Subclavian veins
External iliac veins
Common iliac veins
Femoral veins
Umbilical artery and veins in neonates
what are the ESKAPE pathogens
Enterococcus faecium
Staphylococcus aureus
Klebsiella pneumoniae
Acinetobacter baumannii
Pseudomonas aeruginosa
Enterobacter spp.
what is MRSA
-Methicillin Resistant Staphylococcus aureus
-Found on nose and on the skin of many healthy people without causing harm.
-Causes boils, abscesses , wound infections, sepsis and pneumonia
particularly in those who are already unwell.
-difficult to treat by commonly prescribed antibiotics.
-Some strains of Staphylococcus aureus are resistant to an antibiotic called Methicillin (and up to 18 other antibiotics!!)
Rates have declined over the last decade or so but still a major pathogen.
What are the cost effects of MRSA
Costly interventions that have taken a decade to see results
what is the timeline of MRSA
1959, methicillin introduced in the UK
1961, methicillin resistance first reported
1960’s, methicillin used in labs to detect resistance
1970’s, MRSA outbreaks in UK & Europe
1979, major outbreak in Melbourne Hospital Australia
1981, first epidemic MRSA strain (EMRSA1)
2000+ strains resistant to up to 16 antibiotics
when did penicillin resistance emerge
1940s
in the 1950s what was the % of penicillin resistance
95%
what is C.diff or C.difficile
Clostridioides difficile
It is a Sporeformer Anaerobe, Rod shaped, GI tract inhabitant and CDI is a major cause of death in hospitalised patients - it was a lcoal problem in N.I as well as an international problem
what does C.difficile cause in patients
-induced diarrhea in hospitalized adults
-The disease can be mild or severe= Pseudomembranous colitis, Bowel perforation, Toxic megacolon, Sepsis
-Only occurs after intense antibiotic therapy= disruption of gut normal flora allows C. difficile to grow-Dysbiosis
-Virulence mainly due to two toxins: A and B
-Treatment is supportive and involves discontinuing antibiotic therapy
-Diagnosis is made based on detection of toxins in the stool
what are the treatment options for C.difficile
stopping the antibiotics thought to be causing the infection, if possible
try different antibiotics
taking a 10 to 14-day course of antibiotics that are known to kill C.difficile
what are the mechanisms of control of HAIs
-Aseptic techniques= hand washing and the use of gloves
-Isolation policies
-Food handling procedures
-Disinfection protocols= concurrent and terminal
-Waste disposal regimes
-Surgical wound dressing= SOPs
-Catheter insertion= SOPs
-Cannula insertion= SOPs
(infections rates are decreasing)
how do we prevent the spread of HAIs ( reduce what)
Reduce Contacts= patient-to-patient and staff-to-patient
what are the 2 main isolation strategies
Forward isolation and reverse isolation
what is forward isolation
-Different classes of isolation= Strict, Contact, Private room (self contained) and Respiratory etc.
-Designed to prevent microbes getting from infected patent to others in hospital environment= make COVID wards and Influenza wards in 1918-19
-Strict disinfection programmes
-Negative pressure may be used
Air enters room via unsealed doors etc. and is sterilized by HEPA filters,
prevents airborne organisms within the room entering other parts of the hospital as they cannot move against the air flow
what is reverse isolation
-Private room (self contained)
-Designed to prevent microbes from the hospital environment getting to a severely compromised patient= Immunosuppressed, cancer chemotherapy, Stem cell transplantation etc.
-Positive pressure=Sterile air fed into room (sterilized by HEPA filters) and exits through doors, prevents airborne organisms from entering the room as they cannot move against the air flow
How do we control HAI (pcs)
Prevention= Barrier nursing etc.
Surveillance= Regular checks for the presence of target microbes
Control= Break transmission cycles and Kill/remove pathogens
what are infection control committees
Representative of microbiology laboratory, Infection Control Nurse and Nursing representative
what is the history of infection control
-Ignác Semmelweis (1818-1865)= Observed that up to 1/5 women died from “childbed” puerperal fever after physician-assisted delivery due to Staphylococcus aureus, by contrast, mortality was low in deliveries performed by midwives
-There was no PPE in the mid-19th century! Little disinfection either.
Pathogens, particularly Staphylococcus aureus, easily transferred by direct contact
-Semmelweis discovered that doctors handwashing with carbolic acid prior to delivery dramatically reduced mortality in women
he wrote letters to the establishment outlining his discovery and had opposition
-Suffered a nervous breakdown and was declared a lunatic and institutionalized, died from blood poisoning 10 d after receiving a finger cut while forced into a straightjacket
