Pathogen groups Flashcards
What organisms cause pneumonia?
- S. Pneumoniae (Gram +ve)
- H. Influenzae (Gram -ve)
What tends to cause pneumonia in COPD?
- Usual organisms
- Moraxella
What usually causes pneumonia after flu?
S. Aureus
What organism causes severe, cavitating pneumonia?
Klebsiella (endogenous from own oropharynx)
What organisms cause atypical pneumonia?
Mycoplasma
Clamydophila pneumonia
CI Psittaci
What tends to cause pneumonia is bronchiectasis/CF?
P. Aeruginosa (almost impossible to get rid of, gram -ve rod)
Burkholderia
What causes legionnaires disease? What can it cause?
L. Pneumophila (Gram -ve motile rod)
Lives in warm water but water has to be aerosolised
Severe = renal failure, septic shock, GI features, relative bradycardia (normal HR with pyrexia)
What antibiotics should be given in pneumonia?
Mild: Amoxicillin/Doxy/Clari
Moderate: Amoxicillin + macrolide
Severe: Co-Amox + Macrolide
What are the types of influenza?
A (most severe)
B
C
How does influenza change?
Antigenic Drift & Shift
- Drift: Slight change still partially immune to
- Shift: Dramatic change no longer immune
What can cause meningitis in neonates?
Group B Strep
Listeria
E.Coli (Gram- ve rod)
Viral: Herpes Simplex
What’s the most common cause of meningitis?
Bacterial: Group B
Viral Most common cause, CMV in immunosuppressive
What do you see on an LP in someone with meningitis?
> 10-20cm H20 (raised pressure in meningitis)
White cells <5 (raised)
Protein <0.4
Glucose >50% serum glucose (low in bacterial meningitis)
What is used for meningitis prophylaxis?
Dexamethasone
Ciprofloxacin
Rifampicin (Nisseria)
Why are steroids used in meningitis trreatment?
Morbidity not due to bacterial infection but the inflammatory reaction. Immune response to release of bacterial debris is what is most common cause of morbidity
How is Hep A transmitted?
Face-oral route:
Usually contaminated water (including shellfish)
Direct contact
Male-male sex
What are the Sx of Hep A?
4/52 incubation
Flu-like prodrome
Anorexia
Nausea
Malaise - 2/12
Fatigue
Jaundice & dark urine (come 1/52 after above Sx)
How is Hep A diagnosed?
HAV IgM
How can you protect against Hep A?
Vaccine- 2 doses 6months apart usually before travel gives 10yr protection
What are the complications of chronic Hep B?
Cirrhosis
Heptaoma
30% active hepatitis
How is chronic Hep B cleared?
Interferon
Which antibody appears first in Hep B infection?
Anti- HBc
What does it mean if anti-HBs is detected?
Previous infection
Vaccination
No longer infectious
What does HBsAg detection mean?
Earliest marker of infection
In Absence if e-antigen may indicate carrier
