Lecture 11 Flashcards
Hospital acquired infections
Infections which are acquired in hospital and not present at time of admission
5-10% of patients get them, found in patients and staff
Outline pathogens which can be HAI
95% bacteria, 5% viruses, Parasites
Are HAI usually sporadic
Yes, in 95% of cases
5% as outbreaks in usually ICU or paediatrics
Most common HAI
Surgical sites - 30-35%
UTI - 20%
Pneumonia - Up to 20%
Sepsis - 3-5%
Other up to 20%
Exogenous vs endogenous
Exogenous: Direct inoculation of organism without colonization
Endogenous - Infection by already colonizing microorganisms
Early vs late endogenous
Early: Colonizing flora before hospitalization
Late: Hospital flora - colonizes patient’s body and causes infection flora
What factors relate to HAI
- Microorganism
- Host
- Treatment
- Environment
Opportunistic infection cause
Immunosupression - Cancer, HIV, Tranplants
Breaching defenses - Wound, Urinary catheter
Foreign body e.g. catheter, splinter
Debility e.g. old age
NCI infection possibilities
Patient’s own flora -> Nosocomially colonised patient -> Infected patients
Who is most susceptible to NCI infections
Burn patients
ICU patients
Immunocompromised patients
Surgical patients
Necrotizing fasciitis
Symptoms: Fever, swelling, initial skin changes, hardened skin, overlying skin is shiny and tense
Other signs: bullae, bleeding into skin, gas in tissues, reduced skin sensation
Risk factors of necrotizing fasciitis
Poor immune function
Cancer
Obesity
Alcoholism
Trauma
Incidence of necrotizing fasciitis
0.4/100,000 (USA), 1/100000 (Europe)
M:F ratio equal
Nectrotizing fasciitis: type I
70-80% of cases
Mixture of bacterial types
Usually abdominal or groin
Gram +ve - S. aureus, S. pyogenes, enterococci
Gram -ve - E. coli, P. aeruginosa
Clostridial infections
Account for 10% type I cases
Clostridium perfringens and septicum cause gas gangrene
