Lecture 4 (ID)-Exam 2 Flashcards
Bacterial Meningitis:
* Most likely organism that what?
* What is key to decrease long-term sequelae?
* What is ideally done before antibiotics?
- Most likely organism varies by age
- Rapid diagnosis and treatment is key to decrease long-term sequelae
- Ideally blood cultures and lumbar puncture (LP) should be completed before antibiotic treatment
* Do not delay initiation of therapy for LP / neuroimaging
When should CT be done in bacterial meningitis?
Neuroimaging (CT) indicated for patients with focal neurologic deficits, seizures, immunocompromised, papilledema, altered consciousness to rule out mass or increased intracranial pressure prior to LP
Bacterial Meningitis
When should empiric therapy be based on and how long should they be on it
- Empiric therapy should be based on most likely organism and antibiotic ability to penetrate the CNS
- Empiric therapy should continue for 48 to 72 hours; until bacterial meningitis is ruled out – culture or PCR
- What does inflamation of the meninges cause?
- What antibiotic characterics increase CNS penetration?
Meningitis
Newborn to one month:
* What are the most common organisms? (4)
* What is the empiric therapy?
Organisms: GElH
* Group B streptococci
* E. coli
* Listeria monocytogenes
* Herpes simplex virus (HSV)
Txt:
* Amipicllin plus cefriazone or cefotamine or aminoglycosides and +/- acyclovir (HSV)
Meningitis
1 month to 50 years
* What are the most common organisms? (2)
* What is the treatment?
Organisms:
* S. pneumoniae
* N. meningitidis
Treatment:
* Vanco plus cefriazone plus dexamethasone (start at or before first abx dose)
Meningitis
> 50 years or co- morbidities
* What are the mc organisms (3)
* What is the treatment?
Organisms:
* N. Meningitidis (~50%)
* S. Pneumoniae (~40%)
* Listeria monocytogenes (~5%)
Treatment:
* Vancomycin plus ampicillin plus ceftriaxone plus dexamethasone
- How is neonatal HSV encephalitis happen?
- What is the presentation?
- How do you dx it?
- perinatal transmission of HSV (1 or 2); often no history of maternal herpes infection; maternal disease may be asymptomatic-> Most commonly seen within first month of life
- SEIZURES, INCREASED LIVER ENZYMES, fever, lethargy, poor feeding
- Diagnosis: PCR of CSF
What is the treatment of neonatal hsv encephalitis?
- Acyclovir until HSV ruled-out or 21 days minimum
- Test for cure via CSF PCR at 21 days; if positive treat 7 more days
- Suppressive therapy with acyclovir continued for 6 months
Erysipelas vs cellulitis?
What is this? What organisms (2) is this caused by?
Impetigo-Strep or staph
Common in kids, can be local or diffused
What is this?
Lymphangitis
What are the primary skin and soft tissue infections? What is there organism?
- Erysipelas: Group A Strep (GAS)
- Impetigo: S. aureus, GAS
- Lymphangitis: GAS; occasionally S. aureus
- Cellulitis: GAS, S. aureus, rarely other gm +/g m -, anaerobes
What are the secondary skin and soft tissue infections and the organsims that causes them (2)?
- Bite wounds animal: Pasteurella spp (multocida), S. aureus, Capnocytophaga spp, Bacteroides spp
- Bite wounds human: Eikenella, same as animal bites
What is the first line txt of Erysipelas? What is the second line (lower yield)
Facial?
Oral:
1. Penicillin or amoxicillin
2. Cephalexin (not IgE)
IV:
1. Penicillin or ampicillin
2. Cefazolin (not IgE) or vancomycin (IgE)
Vanco for facial erysepelas
What is the first line txt of impetigo? What is the second line (lower yield)
Oral :
1. Penicillin or Trimethoprim-sulfamethoxazole or mupirocin
topical (if local)
2. Cephalexin
What is the first line txt of Cellulitis? What is the second line (lower yield)
Oral:
1. Cephalexin or dicloxacillin
2. TMP-SMX or clindamycin
IV:
1. Vanco
What are the organisms and treatment of cat BITE?
Organisms:
* Pasteurella multocida (MAIN)
* Staphylococcus aureus
* Capnocytophaga spp
* Bartonella henselae
Txt: Amoxicillin/clavulanate
What are the organisms (4) and first line treatment of a dog BITE? What is the second line (low yield)?
Organisms:
* Pasteurella canis (Dr. Sereda had this one in his PP)
* Staphylococcus aureus
* Capnocytophaga spp
* Bacteroides spp
Treatment:
* First-line: Amoxicillin / clavulanate
* Second-line: Clindamycin plus TMP/SMX or a fluoroquinolone
What are the 3 mc organisms in human bite and what is the first line early, first line infected?
Organisms:
* Streptococci
* Staphylococcus aureus
* Eikenella corrodens
Txt:
* First-line early: Amoxicillin / clavulanate
* First-line infected: ampicillin / sulbactam or cefoxitin or piperacillin / tazobactam
FOR ALL BITE WOUNDS WHAT IS FIRST LINE?
amoxicillin/clavulanate
What is acute osteomyelitis?
Typically presents with a symptom duration of a few days or weeks
* Radiographic changes not evident
What is chronic osteomyelitis?
characterized by long- standing infection over months or years
* Bone ischemia and necrosis common
* Fistula tracts from bone to skin = pathognomonic
What is nonhematogenous OM and Hematogenous OM?
Nonhematogenous osteomyelitis
* Trauma, surgery, soft-tissue infection
Hematogenous osteomyelitis
* Bacteria seed bone in the setting of bacteremia
* Vertebral osteomyelitis MCC – poly microbial
What is the most common organisms for hematogenous and vertebral OM? What is the empiric therapy?
Organism:
* S.aures
* Strep pyogenes
* Salmonella with a pt of sickle cell
Txt:
* Vanco + 3rd/4th gen cephalosporin
What is the mc organisms and empiric therapy for chronic OM?
Organism:
* S. Aureus
* Enterobacteriaceae
* Pseudomonas
Empiric therapy:
* No recommended because you need to wait for results
OM treatment:
* What is essential?
* What is the empiric therapy?
* What is the duration of therapy?
- Bone culture essential unless pathogen isolated from blood
- Vancomycin + ceftriaxone OR ceftazidime OR cefepime
- Duration: 6 to 8 weeks acute infection; longer with chronic infections– exact course dictated by infectious disease specialist-> Conversion to oral therapy once patient stabilizes
OM pathogen specific therapy:
* What is first line for MSSA?
* What is second line?
First line:
* Nafcillin 2gm IV Q4H
* Oxacillin 2gm IV Q4H
* Cefazolin 2gm IV Q8H (first gen)
Alternative
* Clindamycin 600 mg IV Q8H
* Ciprofloxacin 400 mg IV Q8H
* Levofloxacin 750 mg IV Q24H
OM pathogen specific therapy:
* MRSA: what is the first line and second line?
- First: Vancomycin 15 to 20 mg/kg
- Second: Linezolid or Daptomycin
OM pathogen specific therapy:
* Pseudomonas aeruginosa: what is the first line?
- Cefepime 2gm IV Q12H
- Ceftazidime 2gm IV Q8H
SEPTIC ARTHRITIS – ACUTE MONOARTICULAR
* What is is?
* What are the most common organisms?
- Bacterial infection of joint space associated with rapid joint destruction (days)
- MC in healthy adults or prosthetic joints: S.aureus
- Strept pyogenes
- Gram negative is rare ( immunocompromised, IV drug users, elderly)
- +/- N. honorrhea in young adults with STD risk
What are the s/s of septic arthritis?
MC monoarticular joint pain, swelling, erythema, warmth, limited ROM
* +/- systemic symptoms – fever, chills, rigors
What is the txt plan include of septic arthritis?
Treatment plan should include joint aspiration and drainage, antibiotic therapy and orthopedic consult
- What should you do with with synovial fluid aspiration and drainage? What suggestive of septic arthritis?
- Rapid initiation of treatment imperative to prevent
- Cell count, gram stain, culture (gold standard)
- Multiple daily aspirations / surgery may be required
- Purulent fluid with WBC ≥ 50, 000 suggestive of septic arthritis
- Rapid initiation of treatment imperative to prevent joint damage
Acute monoarticular empiric txt is dictated by what?
gram stain and STD risk
ACUTE MONOARTICULAR
* What do you treat if std risk with gram stain negative/gram negative diplococci or gram stain positive?
ACUTE MONOARTICULAR
* What do you treat if no/low std risk with gram stain negative or gram stain positive?
How long is septic arthritis txt?
* When can IV be converted to oral?
Cat scratch disease
* What is the sxs?
* What is the bacteria that causes it?
* Most common in who?
sx: Febrile illness with subacute regional lymphadenopathy
* Self-limited regional lymphadenitis
* 90% patients with high fever and lymphadenopathy
* Spontaneous resolution within 2 to 4 weeks in most cases
* Rarely severe, disseminated disease
Bacteria
* Bartonella henselae - intracellular gram-negative rod
Common in:
* 50% < 18 years of age
How do you diagnosis cat scratch disease?
- ± history of cat contact
- Positive antibody test for Bartonella henselae
What is the txt for cat scratch disease (KNOW THE DOSES) for adults and pediatrics?
First-line: Azithromycin
* Adults: 500mg PO day 1, then 250mg PO daily x 4 days (THINK 500 years old-adult)
* Pediatric patients: 10mg/kg PO day 1, then 5mg/kg PO daily x 4 days (THINK 10 yo kid)
Tooth infections:
* What is the mcc?
* What is the etiology?
- MCC = dental caries or periodontal disease (gingivitis / periodontitis)
- Etiology: polymicrobial including viridians group streptococcus, Peptococcus, Peptostreptococcus, Prevotella
- What is the first line txt for tooth infections (3)?
- What is the txt if penicillin allergic?
First-line:
* Amoxicillin (better gram - coverage)
* Penicillin
* Amoxicillin/clavulanate
Penicillin allergic: Azithromycin or clindamycin