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Table 1.  

Demographic Age-standardized average incidence, 1992–2002 Age-standardized incidence, 2018 Absolute increase in age-standardized incidence Age-standardized incidence risk ratio, 2018 to 1992–2002 baseline (95% CI) Increase in age-standardized incidence, %
Age group, y, not standardized
   0–4 0.03 0.01 −0.03 0.16 (0.02–1.19) −83.52
   5–14 0.02 0.01 −0.01 0.48 (0.15–1.54) −51.61
   15–24 0.07 0.19 0.12 2.80 (2.19–3.57) 179.80
   25–34 0.18 0.75 0.58 4.30 (3.79–4.88) 330.31
   35–44 0.38 1.97 1.59 5.15 (4.74–5.59) 414.89
   45–54 0.66 4.12 3.46 6.28 (5.91–6.69) 528.44
   55–64 1.02 6.52 5.50 6.39 (6.05–6.75) 539.14
   65–74 1.42 7.66 6.24 5.40 (5.11–5.70) 439.63
   75–84 1.57 8.52 6.96 5.44 (5.07–5.84) 444.13
   ≥85 1.49 9.69 8.20 6.50 (5.82–7.27) 550.35
   M 0.63 3.66 3.04 5.86 (5.67–6.05) 485.55
   F 0.35 1.86 1.50 5.29 (5.06–5.53) 429.22
   Native American or Alaska Native 0.26 1.27 1.01 4.93 (3.51–6.93) 392.94
   Asian or Pacific Islander 0.14 0.56 0.42 4.03 (3.19–5.10) 303.18
   Black or African American 0.47 5.21 4.74 11.04 (10.39–11.73) 1003.95
   White 0.37 1.99 1.61 5.30 (5.12–5.49) 430.15
Northeast 0.68 4.82 4.14 7.04 (6.70–7.40) 604.10
   New England 0.61 4.33 3.72 7.10 (6.40–7.87) 610.04
   Middle Atlantic 0.71 5.00 4.30 7.07 (6.69–7.48) 606.98
South 0.33 1.97 1.64 5.97 (5.67–6.29) 497.23
   South Atlantic 0.44 2.29 1.85 5.24 (4.91–5.59) 423.54
   East South Central 0.32 2.05 1.73 6.40 (5.63–7.27) 539.66
   West South Central 0.15 1.36 1.21 9.15 (8.10–10.34) 815.03
Midwest 0.67 4.10 3.43 6.13 (5.85–6.42) 513.06
   East North Central 0.77 5.01 4.24 6.48 (6.16–6.82) 548.02
   West North Central 0.42 2.04 1.62 4.81 (4.29–5.40) 381.38
West 0.29 0.99 0.70 3.39 (3.11–3.68) 238.50
   Mountain 0.43 1.07 0.64 2.47 (2.15–2.83) 146.55
   Pacific 0.23 0.95 0.72 4.13 (3.71–4.59) 312.91
United States 0.48 2.71 2.23 5.67 (5.52–5.83) 467.30

Table. Magnitude of increase in age-standardized incidence of Legionnaires’ disease, cases/100,000 population, from 1992–2002 (average) through 2018, United States

*Ethnicity was not analyzed because data were missing for 30.4% of cases.


Rising Incidence of Legionnaires’ Disease and Associated Epidemiologic Patterns, United States, 1992–2018

  • Authors: Albert E. Barskey, MPH; Gordana Derado, PhD; Chris Edens, PhD
  • CME / ABIM MOC Released: 2/17/2022
  • Valid for credit through: 2/17/2023, 11:59 PM EST
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Target Audience and Goal Statement

This activity is intended for infectious disease specialists, primary care physicians, and other physicians who care for patients at risk for LD.

The goal of this activity is to assess the epidemiology of LD in the US over the past 3 decades.

Upon completion of this activity, participants will:

  1. Analyze trends in the incidence of Legionnaires' disease (LD) according to age
  2. Assess trends in the incidence of LD according to sex
  3. Evaluate trends in the incidence of LD according to race
  4. Distinguish the geographic regions and seasons associated with the highest rates of LD


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  • Albert E. Barskey, MPH

    Centers for Disease Control and Prevention
    Atlanta, Georgia

  • Gordana Derado, PhD

    Centers for Disease Control and Prevention
    Atlanta, Georgia

  • Chris Edens, PhD

    Centers for Disease Control and Prevention
    Atlanta, Georgia

CME Author

  • Charles P. Vega, MD

    Health Sciences Clinical Professor of Family Medicine
    University of California, Irvine School of Medicine


    Disclosure: Charles P. Vega, MD, has disclosed the following relevant financial relationships:
    Served as an advisor or consultant for: GlaxoSmithKline; Johnson & Johnson Pharmaceutical Research & Development, L.L.C.


  • Jill Russell, BA

    Emerging Infectious Diseases


    Disclosure: Jill Russell, BA, has disclosed no relevant financial relationships.

CME Reviewer

  • Leigh A. Schmidt, MSN, RN, CMSRN, CNE, CHCP

    Associate Director, Accreditation and Compliance
    Medscape, LLC


    Disclosure: Leigh A. Schmidt, MSN, RN, CMSRN, CNE, CHCP, has disclosed no relevant financial relationships.

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Rising Incidence of Legionnaires’ Disease and Associated Epidemiologic Patterns, United States, 1992–2018

Authors: Albert E. Barskey, MPH; Gordana Derado, PhD; Chris Edens, PhDFaculty and Disclosures

CME / ABIM MOC Released: 2/17/2022

Valid for credit through: 2/17/2023, 11:59 PM EST



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