Flashcards in Community acquired infections Deck (21):
What are the most common bacteria infections in meningitis for 3 month - 50 year olds?
What about 50+?
Hib used to be a big deal, pre-vaccination era
In the over 50s, or those with immunosuppression, we worry about Listeria monocytogenes
which populations are more susceptible to pneumococcus?
what are the serotypes of N. meningitidis?
what's in the vaccine?
a,b,c, y and W-135
the vaccine does not contain the B serotype, but a reverse engineered vaccine has recently become available
what are the contact treatments for meningococcus?
if pregnant, CTX 250mg IM
cipro 500mg once
Penicillin will not eradicate carriage
what is the treatment for meningitis, when gram-positive cocci in pairs are seen on gram-stain of CSF?
are there any other times when meningitis treatment is changed?
in this setting it is recommended that we give CTX/cefotaxime PLUS vancomycin at high doses
CAN STILL USE PENICILLIN FOR CHEST INFECTIONS - CAN GET HIGH TISSUE LEVELS IN THAT SETTING
what are the new treatment guidelines for meningitis in Australia?
what about if pen allergic?
describe the different types of pen allergies
if there is a delayed penicillin reaction/rash ONLY
then we use CTX 2g BD
If immediate hypersens rxn (angioedema, urticaria, anaphylaxis, bronchospasm)
- vancomycin PLUS cipro
single agent moxifloxacin (400mg IV)
how does listeria meningitis present?
what does the Gram stain look like?
it is in the older, immunocompromised patients
there is rhombencephalitis with cranial nerve signs, ataxia can occur
hemiplegia can occur
seizures may be a finding
PARTICULARLY FOCAL FINDINGS
Gram stain is Gram pos rods
this bug is intrinsically resistant to cephalosporins, so use BenPen or Amp
what are the CSF findings of encephalitis?
usually normal glucose
85% have increased red cells
add aciclovir until HSV encephalitis is excluded!
what are the common causes of brain abscess in an immunocompetent person?
it is a polymicrobial infection
esp S. milleri and anaerobes
treatment is aspiration
ABx = CTX and metronidazole
what is the empirical treatment of an abscess less than 5cm when patient systemically well?
incision and drainage.
what are the two most common pathogens in skin/soft tissue infection?
strep pyogenes (Group A) - erbcellicent cellulitis
staph aureus in focus disease (like abscesses and furuncles
what is the distinction between multi-resistant MRSA and non-multiresistant MRSA?
mMRSA = resistant to fluclox PLUS three additional classes of antibiotic (e.g. gent, TMP/STX, lincomycin) - this used to be HA-MRSA
nmMRSA = resistant to fluclox, but susceptible to other classes - this used to be called CA-MRSA
- this usually requires trimethoprim-sulphamethoxazole or clindamycin for treatment
what is the Panton-Valentine-Leukocidin cytotoxin?
this is apparently a cytotoxin that increases virulence
it is classically associated with nmMRSA
seems to be associated to with outbreaks
what is the classical bug from a freshwater, waterborne skin infection?
- Gram neg rod
- fresh water predeominance
- very rapid onset of disease
- Fluoroquinolones are the agent of choice
STRONGLY ASSOCIATED WITH TRAUMA
what is the super nasty bug that is associated with estuary habititats?
- gram neg
- classic "flesh eating" bug
- free living in the estuary and marine habitats
Almost always occurs in those with co-morbidities, esp liver diease/EtOH or HCM
fulminant infection with necrosis and septic shock
treat with doxycycline
what is the cause of "fish tank cellulitis"?
associated with skin/soft tissue infection after cleaning out a fish tank!
- acid fast bacillus
- diagnosis is of granulomas and culture of tissue sample
treatment is excision +/- clari+ethambutol
what are the common bugs in animal bites?
what is empirical treatment?
these are typically considered low risk wounds, unless the involve joints/tendons and do not need empirical ABs if debrided within 8 hours
they are often polymicrobial
involved organisms include:
- natural skin flora (staph, strep) plus the animal oral flora
dogs and cats:
1. most important is Pasteurella multocida
2. capnocytophagia canimorsus
3. anaerobes and microaerophilic Streptococic
Bartonella henselae is a RARE organism - results from cat scratches rather than bites
oral Aug DF
or IV Pip/taz
what are the bugs in nec fasc?
there are two major variants:
- strep pyogenes
- staph aureus
- clostridium perfringens (gas gangrene)
- waterborne Gram-negs
2. polymicrobial/synergistic gangrene
- Fournier's gangrene
- diabetes or other immune compromise
what is the antimicrobial treatment of nec fasc?
broad spectrum to cover everything, AND MRSA AND add an anti-toxin
usually this would mean:
- clindamycin for its anti-toxin effects against toxin-releasing bugs like strept and staph
- an agent with definite MRSA activity (vanco)
what is the most common cause of acute diarrhoea in Australia?
rotavirus, norovirus, adenovirus, astrovirus
it is managed with supportive care and close infection control
these are notifiable diseases and are particularly relevant in nursing homes/aged care facilities