Legionella

Background

  • Gram negative aerobe
  • L. pneumophila: associated with two distinct syndromes: pneumonia (legionnaires disease) and Pontiac Fever
  • Infection typically occurs via inhalation of aerosolized contaminated water or aspiration of contaminated water
    • Outbreaks often associated with cooling towers, hot tubs, medical equipment
    • Increased incidence with hot, humid, weather and thundershowers
  • Most commonly found in patients age > 50 years, smokers, immunocompromised.[1]
    • However, likely underestimated in children[2]

Clinical Features

  • Pontiac fever[3]
    • Fever, mild flu-like illness
    • Absence of pneumonia
  • Legionnaires disease[4]
    • High mortality
    • Incubation 2-10d[5]
    • Fever, often high
    • Cough
    • Respiratory distress
      • Respiratory failure in ~10% of all cases[6]
    • Relative [[bradycardia (relative to temperature)
  • Gastrointestinal symptoms (e.g. nausea/vomiting, diarrhea)
  • Neurologic symptoms

Gastrointestinal symptoms Neurologic symptoms Can cause tremor, seizures, Guillain-Barre, and chorea. Has been linked to cases of Acute Cerebellar Ataxia. [Nigro, 1983] Respiratory failure occurs in ~10% of all cases.

Differential Diagnosis

Causes of Pneumonia

Bacteria

Viral

Fungal

Parasitic

Evaluation[7]

  • Sputum sample for culture
  • Urine legionella antigen
  • Na: Low in CAP but mostly frequently associated with Legionella
  • AST/ALT: Mildly increased 2-5x normal
  • Phosphate: Decreased
  • CK: Increased
  • CRP: > 35
  • Ferritin: Increased >2x normal

Management

Antibiotic Sensitivities[10]

Category Antibiotic Sensitivity
PenicillinsPenicillin GR
Penicillin VR
Anti-Staphylocccal PenicillinsMethicillinR
Nafcillin/OxacillinR
Cloxacillin/Diclox.R
Amino-PenicillinsAMP/AmoxR
Amox-ClavR
AMP-SulbR
Anti-Pseudomonal PenicillinsTicarcillinR
Ticar-ClavR
Pip-TazoR
PiperacillinR
CarbapenemsDoripenemR
ErtapenemR
ImipenemR
MeropenemR
AztreonamR
FluroquinolonesCiprofloxacinS
OfloxacinS
PefloxacinS
LevofloxacinS
MoxifloxacinS
GemifloxacinS
GatifloxacinS
1st G CephaloCefazolinR
2nd G. CephaloCefotetanR
CefoxitinR
CefuroximeR
3rd/4th G. CephaloCefotaximeR
CefizoximeR
CefTRIAXoneR
CeftarolineR
CefTAZidimeR
CefepimeR
Oral 1st G. CephaloCefadroxilR
CephalexinR
Oral 2nd G. CephaloCefaclor/LoracarbefR
CefproxilR
Cefuroxime axetilR
Oral 3rd G. CephaloCefiximeR
CeftibutenR
Cefpodox/Cefdinir/CefditorenR
AminoglycosidesGentamicinX1
TobramycinX1
AmikacinX1
ChloramphenicolX1
ClindamycinX1
MacrolidesErythromycinS
AzithromycinS
ClarithromycinS
KetolideTelithromycinX2
TetracyclinesDoxycyclineX2
MinocyclineX2
GlycylcyclineTigecyclineX2
DaptomycinR
Glyco/LipoclycopeptidesVancomycinX1
TeicoplaninX1
TelavancinX1
Fusidic AcidI
TrimethoprimS
TMP-SMXS
Urinary AgentsNitrofurantoinX1
FosfomycinX1
OtherRifampinX1
MetronidazoleR
Quinupristin dalfoppristinX1
LinezolidX1
ColistimethateX1

Key

  • S susceptible/sensitive (usually)
  • I intermediate (variably susceptible/resistant)
  • R resistant (or not effective clinically)
  • S+ synergistic with cell wall antibiotics
  • U sensitive for UTI only (non systemic infection)
  • X1 no data
  • X2 active in vitro, but not used clinically
  • X3 active in vitro, but not clinically effective for Group A strep pharyngitis or infections due to E. faecalis
  • X4 active in vitro, but not clinically effective for strep pneumonia

Table Overview

See Also

References

  1. Cunha BA. Legionnaires' disease: clinical differentiation from typical and other atypical pneumonias. Infect Dis Clin N Am. 2010;24(1):73-105.
  2. Yu VL1, Lee TC. Neonatal legionellosis: the tip of the iceberg for pediatric hospital-acquired pneumonia? Pediatr Infect Dis J. 2010 Mar;29(3):282-4.
  3. https://wwwnc.cdc.gov/travel/yellowbook/2020/travel-related-infectious-diseases/legionellosis-legionnaires-disease-and-pontiac-fever
  4. https://wwwnc.cdc.gov/travel/yellowbook/2020/travel-related-infectious-diseases/legionellosis-legionnaires-disease-and-pontiac-fever
  5. Eison, R. Legionella Pneumonia: When to Suspect, Diagnostic Considerations, and Treatment Strategies for Hospital-Based Clinicians. Curr Emerg Hosp Med Rep (2014) 2: 205.
  6. https://pedemmorsels.com/legionellosis-in-children/
  7. Cunha BA. Legionnaires' disease: clinical differentiation from typical and other atypical pneumonias. Infect Dis Clin N Am. 2010;24(1):73-105.
  8. https://www.cdc.gov/legionella/downloads/case-report-form.pdf
  9. Burke et Al. Legionnaires Disease Treatment & Management. Aug 18, 2014. http://emedicine.medscape.com/article/220163-treatment#d11
  10. Sanford Guide to Antimicrobial Therapy 2014
This article is issued from Wikem. The text is licensed under Creative Commons - Attribution - Sharealike. Additional terms may apply for the media files.