W6- Lecture 28- Hospital acquired infections Flashcards
have you done the two activity workbooks
yes-well done
no- please complete them
define nosocomial
The medical term for a hospital-acquired infection
Anosocomialinfection is strictly and specifically an infection “not present or incubating prior to admittance to the hospital, but generally occurring 48 hours after admittance.
aka healthcare associated infections
what are the three largest healthcare-associated infections
Respiratory infections (including pneumonia and infections of the lower respiratory tract) (22.8%)
Urinary tract infections (17.2%)
Surgical site infections (15.7%)
what are the Risk factors for a nosocomial infection
Duration of hospital stay Indwelling catheters Mechanical ventilation Use of total parenteral nutrition Antibiotic usage Use of histamine (H2) receptor blockers (owing to relative bacterial overgrowth) Age—more common in neonates, infants, and the elderly Immune deficiency
define Hospital Acquired Pneumonia (HAP)
Hospital-acquired pneumonia(HAP) ornosocomial pneumoniarefers to anypneumoniacontracted by a patient in ahospitalat least 48–72 hours after being admitted.
what are the Common bacteria involved in hospital-acquired pneumonia (HAP)
Pseudomonas aeruginosa
Staphylococcus aureus, including methicillin-susceptible S aureus (MSSA) and methicillin-resistant S aureus (MRSA)
Klebsiella pneumoniae
Escherichia coli
Non-Enterobacteriaceae bacteria such as Serracia marcescens, Stenotrophomonas maltophilia, and Acinetobacter species are less common causes
what is a Urinary Tract Infection (UTI)
any associations with catheter ?
A urinary tract infection (UTI) is an infection involving any part of the urinary system, including urethra, bladder, ureters, and kidney
75% of hospital acquired UTI are associated with a catheter
what are the Common bacteria involved in hospital-acquired UTI’s
Enteric pathogens (eg,Escherichia coli) are most commonly responsible but also:
Pseudomonasspecies
Enterococcusspecies
Staphylococcus aureus
Coagulase-negative staphylococci
Enterobacterspecies, and yeast also are known to cause infection.
ProteusandPseudomonasspecies are the organisms most commonly associated with biofilm growth on catheters.
Candida, especiallyCandida albicans, is the second-most-common organism that can cause catheter-associated urinary tract infection.
what is sepsis
when the body’s response to infection injuresits own tissues and organs. organs to begin to fail
Sepsis can be triggered by any infection, but mostcommonly occurs in response to bacterial infections ofthe lungs, urinary tract, abdominal organs or skin andsoft tissues
what other conditions is sepsis normally associated with ?
GI tract – Liver disease, gallbladder disease, colon disease, abscess, intestinal obstruction, and GI instrumentation
GU tract – Pyelonephritis, intra- or perinephric abscess, renal calculi, urinary tract obstruction, acute prostatitis or abscess, renal insufficiency, and GU instrumentation
Pelvis – Peritonitis and pelvic abscess
Lower respiratory tract – Community-acquired pneumonia (with asplenia), empyema, and lung abscess
Vascular system – Infected IV line or prosthetic device
Heart and cardiac vasculature – Acute bacterial endocarditis and myocardial or perivalvular ring abscess
what is the Pathophysiology of sepsis
Infection
Excessive cytokine release
Amplification -> capillary dilatation&↑permeability
-> oedema of tissues
Hypotension -> tachycardia
-> reduced urine output
-> reduced cardiac output
-> multi organ failure
Anaerobic respiration-> increase blood lactate
Death or significant morbidity
what is the Management of sepsis( The sepsis six)
- Administer oxygen to maintain Oxygen saturation (SpO2)>94%
- Take blood cultures and consider infectivesource
- Administer intravenous antibiotics
- Considerintravenousfluidresuscitation
- Check serial lactates
- Commence hourly urine outputmeasurement
what is Meticillin-resistant Staphylococcus aureus (MRSA)
Meticillin-resistant Staphylococcus aureus (MRSA) is a gram-positive bacterium that is genetically different from other strains of Staphylococcus aureus
MRSA is now resistant to all forms of penicillin and cephalosporin
which antibiotics do we use to treat MRSA
Vancomycin* Teicoplanin Doxycycline Rifampicin Clindamycin Trimethoprim Gentamicin Linezolid Daptomycin
what is Clostridium difficile (C.Diff)
Spore-forming anaerobic Gram positive bacillus bacterium
Spores facilitate the organism’s survival in conditions of adversity (resistant to heat, drying, stomach acids, alcohol and some chemicals)
Produces exotoxins A and B
Toxins cause inflammation of the intestinal wall resulting in spectrum of disease:
Antibiotic associated diarrhoea (AAD)
Antibiotic associated colitis (AAC)
Pseudomembranous colitis (PMC)
Fulminant colitis
Risk factors for infection of Clostridium difficile (C.Diff)
Any antibiotic can induce Clostridium difficile associated diarrhoea (CDAD)
Antibiotics alter normal gut flora allowing C. difficile to flourish and produce toxins
CDAD can occur up to 2 months after exposure to antibiotics
which antibiotics are low risk for causing Clostridium difficile associated diarrhoea risk
Low risk(narrow spectrum antibiotics) Trimethoprim Nitrofurantoin Metronidazole Gentamicin
Intermediate Penicillins Co-amoxiclav Macrolides Tetracyclines Pipericillin/tazobactam Glycopeptides Meropenem
High risk
Cefalosporins
Ciprofloxacin
Clindamycin
IV
Multiple courses
Prolonged
Combinations
risk factors for CDI (aside from AntiBiotics )
≥65 years
Previous C.difficile infection
Recent hospitalisation (exposure to environmental spores / close contact with infected others )
Previous antibiotic exposure
Extensive / severe co-morbidity
Immunocompromised (malignancy, HIV, chemotherapy, etc.)
Long term prescription of proton-pump inhibitors (PPIs) eg omeprazole
what is the Treatment for CDI (c.diff infection)
Asymptomatic carriers require no treatment
Symptomatic patients:
15 – 25% respond to conservative treatment
If possible STOP antibiotics - allows re-establishment of normal colonic micro flora and reduces risk of relapse
Supportive therapy (observe for sepsis, rehydrate, toileting, etc.)
Dietician referral – aim for balanced, nutritional oral intake with good fibre content
what is Glycopeptide Resistant Enterococci (GRE)
Enterococcus species frequently found in bowel of normal, healthy individuals
Only a few species have potential to cause infections in humans
May cause a range of illnesses including:
Urinary tract infections,
Bacteraemia
Wound infections
Glycopeptide antibiotics include Vancomycin and Teicoplanin
2 most common species ofGREare E. faecalis and E. faecium
risk factors for Glycopeptide Resistant Enterococci (GRE)infection
GREoccur mainly in hospital patients, such as those:
Who are immunocompromised
Having had previous treatment with other antibiotics (particularly cephalosporins and glycopeptides)
On prolonged hospital stay
In specialist critical units
what are the Vancomycin Resistant Enterococci treatment options
different for the 2 different species
Enterococcus faecalis – amoxicillin
Enterococcus faecium – resistant to amoxicillin
Other options:
Linezolid
Daptomycin
what are Extended-spectrum beta-lactamases (ESBLs)
Extended-Spectrum Beta-Lactamases (ESBLs) are enzymes that can be produced by bacteria making them resistant to cefalosporins.
widely detected among Escherichia coli ( E. coli) bacteria
These ESBL-producing E. coli are resistant to penicillins and cephalosporins and are found most often in urinary tract infections (UTI’s)
what are Extended-spectrum beta-lactamases (ESBLs)
1) resistance to
2) susceptible to ?
1)Usually confer resistance to:
First-, second- and third-generation cephalosporins(e.g. cefalexin, cefuroxime, ceftriaxone)
Amoxicillin and co-amoxiclav and aztreonam
Plasmids also contain resistance genes to:
Ciprofloxacin
Trimethoprim
2)Usually confer resistance to:
First-, second- and third-generation cephalosporins(e.g. cefalexin, cefuroxime, ceftriaxone)
Amoxicillin and co-amoxiclav and aztreonam
Plasmids also contain resistance genes to:
Ciprofloxacin
Trimethoprim
