Week 13 Flashcards
Nosocomial infections (4)
- infection occuring in a patient during the process of care that was NOT present or incubating at time of admission
- any type of setting (hospital, health care facility etc.)
- can also appear after discharge
- affects patients and staff
Nosocomial infections - when is an illness considered nosocomial
- when symptoms present 48 to 72 hours after admission (depends on incubation period)
Factors causing development of Nosocomial Infections (2)
- decreased host defenses (critically ill, antibiotics, etc)
- colonization by pathogenic bacteria (antibiotic resistant, etc)
How common are nosocomial infections
- 1/10 patients get an infection while recieving care
How many surgical site infections are nosocoimal
more than 50% of surgical site infections are antibiotic-resistant
- EX MRSA
Impacts of nosocomial infection (6)
- prolonged hospital stay
- long-term disability
- increased resistance of microorganisms to antimicrobials
- additional cost for healthcare system
- additional cost for patients and their family
- death
Factors that predispose to nosocomial infection (4)
- underlying health status-
- acute disease process
- Invasive procedures
- related to treatment
Nosocomial Infection: underlying health status (7)
- impairment of host-defence mechanisms
- advanced age
- malnutrition
- alcoholism
- smoking
- chronic lung disease
- diabetes
Nosocomial Infection: acute disease process (4)
- surgery
- trauma (altered immune response)
- burns (open wounds, no skin as barrier)
- use of ventilators –> pneumonia
Nosocomial Infection: invasive procedures (6)
- endotracheal/nasal intubation
- central venous catheterization
- extracorporeal renal support
- surgical drains
- NG tube
- urinary catheter
Nosocomial Infection: related to treatment (5)`
- blood transfusions
- recent antimicrobial therapy
- immunosupporessive treatment (corticosteroids, chemo)
- recumberent position
- parenteral nutrition
Causes of nosocomial infections (7)
- Healthcare providers: transmit person-to-person
- infected personal equipment (stethoscopes, bladder scan)
- medical equipment inappropriately reprocessed
- environmental contamination
- airborne transmission
- carriers on the hospital staff
- antimicrobial misuse/resistance
Incidence of Hospital aquired infectiosn
1) UTI – catheterization
2) pneumonia
3) surgical wound infection
4) skin infections
Hospital organisms - UTI (4)
- E. Coli
- P. Aeruginosa
- Klebesiella
- Enterobacter
Hospital organisms - Resp (5)
- staph aureus-
- gram negative rods (pseudonomas aeruginosa)
- streptococcus pneumoniae
- TB
- VZV
Hospital Organisms - Diarrhea/vomiting (2)
- C. Difficile
- Norovirus
Hospital Organisms - Blood (3)
- Hep B
- Hep C
- HIV
Most infectious Hospital Organisms (4)
- VISA = vancomycin resistant staph aureus
- VRE = vancomycin resistant enterococcus
- MDR_TB = multi drug resistant TB
- Fungal pathogens = esp Candida Spp
Clostridium Difficile - shape
rod
Clostridium Difficile - gram status
- gram positive
Clostridium Difficile - where
normal microbiome of healthy people
Clostridium Difficile - pathogenesis
- Longterm antibiotic use –> antibiotic associated diarreha caused by C. Difficile
Clostridium Difficile - at risk populations (6)
- immunocompromised
- health care settings for extended periods
- older adults
- recently taken antibiotics
- had gastrointestinal procedures done
- use proton pump inhibitors (reduce stomach acidity)
Clostridium Difficile - how it causes harm in the body
- produces two toxins (c. diff toxin A = TcdA, and c. diff toxin B = TcdB)
- these toxins inactivate GTP binding protein = actin condensation and cell rounding = cell death
- casues focal necrosis, then ulceration, then pseudomembranous collitis (inflammation of colon)
Clostridium Difficile - symptoms (5)
- watery diarrhea
- dehydration
- fever
- loss of appetite
- abdominal pain
Clostridium Difficile - complications (6)
- perforation of colon
- septicemia
- shock
- death
- necrotizing enterocolitis (premature babies)
- neutropenic enterocolitis (cancer therapies)
Clostridium Difficile - diagnosis (6)
- patient history
- clinical presentation
- imaging
- endoscopy
- lab tests
- detecting toxin in stool samples (culture rarely used)
Clostridium Difficile - treatment (4)
- stop antibiotic use
- provide supportive therapy (electrolytes and fluids)
- Metronidazole is prefered if C diff is confirmed
- Vancomycin can be used if Met was ineffective or other criteria are met (under 10, allergy, etc.)
Antimicrobial resistance
- when microbes develop the ability to resist the effects of drugs
- they are then not killed and their growth does not stop
- common in hospitals (esp. intensive care)
- caused by overprescription of antibiotics in office-based physicians = antibiotics lose impact
Prevention of antimicrobial resistance
- identify presence of definite infectious process
- use narrow-spectrum antibiotics where possible
Antibiotic resistant bacteria examples (9)
MRSA
VISA
VRE
Streptococcus pneumoniae
Enterobacter (ie ESBL)
Acinetobacter
Pseudomonas aeruginosa
MDR-TB
extended spectrum beta lactamase
Risk factors for infection with drug-resistant bacteria (4)
- Antimicrobial therapy in preceding 90 days
- Current Hospitalization for > 5 days
- High frequency of antibiotic resistance in the community or in the specific hospital unit
- Immunosuppression
Routes of transmission of nosocomial infections (6)
- Unwashed hands: MRSA, VISA, VRE, C Difficile, norovirus
- Respiratory secretions: TB, VZV
- Aerosolized vomit: Norovirus
- Faeces: C difficile, Norovirus
- Fomites: MRSA VISA, VRE, C. Difficile
- Contaminated Needles and Surgical Equipment: HCB, HCV, HIV
