Legionnaire's disease
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Etiology
Epidemiology
- peak activity in warm, rainy, & humid conditions[9]
- primarily affects older patients[9]
- more common among cigarette smokers, immunocompromised patients, & patients with chronic lung disease[9]
- 20% of Legionnaires' disease cases were probably or definitely acquired in healthcare facilities[8]
- affects younger persons sharing hot tub[4]
Clinical manifestations
- incubation period is 2-10 days
- general
- pulmonary
- non-productive cough (abrupt onset)
- hemoptysis (30%)
- dyspnea
- gastrointestinal symptoms
- musculoskeletal
- headache
- relative bradycardia
- delirium
Laboratory
- serum sodium: hyponatremia (50-70%)
- serum phosphate: hypophosphatemia (50%)
- complete blood count
- leukocytosis > 10,000/mm3 (60%)
- relative lymphopenia,
- serum protein: proteinuria (20%)
- serum AST increased (60%)
- urine Legionella antigen testing for serogroup 1
- 1st line diagnostic test[9]
- sensitivity 60-80%; specificity > 99%
- remains positive for days after administration of antibiotics
- Legionella DNA testing may increase diagnostic yield[6]
- sputum gram stain
- faintly gram-negative bacillus
- difficult to detect by Gram stain[9]
- sputum culture
- see Legionella for other diagnostic laboratory studies
- see ARUP consult[6]
Radiology
- diffuse, patchy infiltrates
- ill-defined nodules
- bilateral lobar-segmental involvement
- case with left lower lobe consolidation[4]
Management
- antimicrobial therapy
- macrolide
- azithromycin[9]
- erythromycin
- Rifampin 600 mg PO QD may be synergistic
- respiratory fluoroquinolone
- levofloxacin as effective as macrolide[5]
- alternative antibiotics
- macrolide
- Legionella endocarditis
- valve replacement
- 3-12 months of antibiotic therapy
More general terms
Additional terms
References
- ↑ Manual of Medical Therapeutics, 28th edition, Ewald & McKenzie (eds) Little, Brown & Co, 1995, pg 302
- ↑ Harrison's Principles of Internal Medicine, 13th ed. Companion Handbook, Isselbacher et al (eds), McGraw-Hill Inc. NY, 1995, pg 228-29
- ↑ Mayo Internal Medicine Board Review, 1998-99, Prakash UBS (ed) Lippincott-Raven, Philadelphia, 1998, pg 797
- ↑ 4.0 4.1 4.2 Medical Knowledge Self Assessment Program (MKSAP) 11, 18, 19. American College of Physicians, Philadelphia 1998, 2018, 2021.
Medical Knowledge Self Assessment Program (MKSAP) 20 American College of Physicians, Philadelphia 2025 - ↑ 5.0 5.1 Journal Watch 25(8):63-64, 2005
Blazquez Garrido RM, Espinosa Parra FJ, Alemany Frances L, Ramos Guevara RM, Sanchez-Nieto JM, Segovia Hernandez M, Serrano Martinez JA, Huerta FH. Antimicrobial chemotherapy for legionnaires disease: levofloxacin versus macrolides. Clin Infect Dis. 2005 Mar 15;40(6):800-6. Epub 2005 Feb 17. PMID: https://pubmed.ncbi.nlm.nih.gov/15736011 - ↑ 6.0 6.1 6.2 Murdoch DR et al. Impact of routine systematic polymerase chain reaction testing on case finding for Legionnaires' disease: A pre - post comparison study. Clin Infect Dis 2013 Nov 1; 57:1275 <PubMed> PMID: https://pubmed.ncbi.nlm.nih.gov/23899682 <Internet> http://cid.oxfordjournals.org/content/57/9/1275
- ↑ ARUP Consult: Legionella pneumophila The Physician's Guide to Laboratory Test Selection & Interpretation https://www.arupconsult.com/content/legionella-pneumophila
- ↑ 8.0 8.1 Soda EA, Barskey AE, Shah PP, et al. Vital Signs: Health Care-Associated Legionnaires' Disease Surveillance Data from 20 States and a Large Metropolitan Area - United States, 2015. MMWR Morb Mortal Wkly Rep . ePub: 6 June 2017. https://www.cdc.gov/mmwr/volumes/66/wr/mm6622e1.htm
- ↑ 9.0 9.1 9.2 9.3 9.4 9.5 9.6 9.7 Rothaus C An Unexpected Expectoration. NEJM Resident 360. Feb 28, 2018 https://resident360.nejm.org/content_items/an-unexpected-expectoration
- ↑ Cunha BA. Legionnaires' disease: clinical differentiation from typical and other atypical pneumonias. Infect Dis Clin North Am. 2010 Mar;24(1):73-105. Review. PMID: https://pubmed.ncbi.nlm.nih.gov/20171547
- ↑ Centers for Disease Control & Prevention (CDC) Legionella (Legionnaires' Disease and Pontiac Fever) https://www.cdc.gov/legionella/index.html
Centers for Disease Control & Prevention (CDC) Developing a Water Management Program to Reduce Legionella Growth and Spread in Buildings. A Practical Guide to Implementing Industry Standards. https://www.cdc.gov/legionella/maintenance/wmp-toolkit.html