Surveillance Report 2018-2019

What to know

This page features accessible versions of tables in the 2018-2019 Legionnaires’ Disease Surveillance Summary Report.

Thumbnail image of the 2018-2019 surveillance summary report for Legionnaires' disease

Full report

Access the full report.

Tables and figures

Section 1: National Notifiable Diseases Surveillance System (NNDSS)

Figure 1: Crude incidence rates of reported confirmed cases of Legionnaires’ disease* by year—NNDSS, United States, 2000–2019.

Figure 2: Number of reported confirmed cases of Legionnaires’ disease* by month and year—NNDSS, United States, 2018 and 2019.

Figure 3a: Crude incidence rates of reported confirmed cases of Legionnaires’ disease* by jurisdiction of residence—NNDSS, United States, 2018.

Figure 3b: Crude incidence rates of reported confirmed cases of Legionnaires’ disease* by jurisdiction of residence—NNDSS, United States, 2019.

Table 1: Number of reported confirmed cases of Legionnaires’ disease* by jurisdiction of residence and year—NNDSS, United States, 2018 and 2019.

Table 2: Number, percent, and crude incidence rates of reported confirmed cases of Legionnaires’ disease* by demographic characteristics and year—NNDSS, United States, 2018 and 2019.

 

Section 2: National Notifiable Diseases Surveillance System comparison with Supplemental Legionnaires’ Disease Surveillance System (SLDSS)

Figure 4a: Percent of reported confirmed cases of Legionnaires’ disease*§ by age group and year—NNDSS and SLDSS, United States, 2018 and 2019.

Figure 4b: Percent of reported confirmed cases of Legionnaires’ disease*§ by sex and year—NNDSS and SLDSS, United States, 2018 and 2019.

Figure 4c: Percent of reported confirmed cases of Legionnaires’ disease*§ by race and year—NNDSS and SLDSS, United States, 2018 and 2019.

Figure 4d: Percent of reported confirmed cases of Legionnaires’ disease*§ by ethnicity and year—NNDSS and SLDSS, United States, 2018 and 2019.

 

Section 3: Supplemental Legionnaires’ Disease Surveillance System

Figure 5a: Reported confirmed cases of legionellosis± by syndrome and completeness of jurisdictional reporting—SLDSS, United States, 2018.

Figure 5b: Reported confirmed cases of legionellosis± by syndrome and completeness of jurisdictional reporting—SLDSS, United States, 2019.

Figure 6a: Number of reported confirmed cases and deaths of Legionnaires’ disease§ by exposure category—SLDSS, complete reporting jurisdictions, 2018.

Figure 6b: Number of reported confirmed cases and deaths of Legionnaires’ disease§ by exposure category—SLDSS, complete reporting jurisdictions, 2019.

Table 3: Number of reported confirmed cases of Legionnaires’ disease§ by exposure category and year—SLDSS, complete reporting jurisdictions, 2018 and 2019.

Table 4a: Number of reported confirmed cases of Legionnaires’ disease§ by demographic characteristics and exposure category—SLDSS, complete reporting jurisdictions, 2018.

Table 4b: Number of reported confirmed cases of Legionnaires’ disease§ by demographic characteristics and exposure category—SLDSS, complete reporting jurisdictions, 2019.

Table 5a: Number of reported confirmed cases of healthcare-associated Legionnaires’ disease§ by healthcare facility type and exposure certainty—SLDSS, complete reporting jurisdictions, 2018.

Table 5b: Number of reported confirmed cases of healthcare-associated Legionnaires’ disease§ by healthcare facility type and exposure certainty—SLDSS, complete reporting jurisdictions, 2019.

Table 6a: Number of reported confirmed cases of Legionnaires’ disease§ by hospitalization, outcome, and exposure category—SLDSS, complete reporting jurisdictions, 2018.

Table 6b: Number of reported confirmed cases of Legionnaires’ disease§ by hospitalization, outcome, and exposure category—SLDSS, complete reporting jurisdictions, 2019.

Figure 7: Percent of reported confirmed cases of Legionnaires’ disease§ that were treated in hospital by age group and year—SLDSS, complete reporting jurisdictions, 2018 and 2019.

Figure 8: Percent of reported confirmed cases of Legionnaires’ disease§ resulting in death by age group and year—SLDSS, complete reporting jurisdictions, 2018 and 2019.

Table 7: Number of reported confirmed cases of Legionnaires’ disease§ by diagnostic testing method and year—SLDSS, United States, 2018 and 2019.

*Cases of disease due to Legionella are reported to NNDSS as legionellosis, which includes Legionnaires’ disease, Pontiac fever, and extrapulmonary legionellosis, but are referred to as Legionnaires’ disease in this figure or table (because almost all legionellosis cases reported in the United States are Legionnaires’ disease cases).
§ Only cases of Legionnaires’ disease reported to SLDSS are included in this figure or table.
± All cases of legionellosis (i.e., Legionnaires’ disease, Pontiac fever, and extrapulmonary legionellosis) reported to SLDSS are included in this figure.

Figure 1. Crude incidencea  rates of reported confirmed cases of Legionnaires’ diseaseb by yearc—NNDSS,d,e United States, 2000–2019.

Figure 1. Crude incidence rates of reported confirmed cases of Legionnaires’ disease by year—NNDSS, United States, 2000–2019
aCrude incidence of cases per 100,000 population (number of confirmed Legionnaires' disease cases reported that year divided by postcensal population estimate for that year times 100,000 population).
bCases of disease due to Legionella are reported to NNDSS as legionellosis, which includes Legionnaires’ disease, Pontiac fever, and extrapulmonary legionellosis, but are referred to as Legionnaires’ disease in this figure (because almost all legionellosis cases reported in the United States are Legionnaires’ disease cases).
cBased on year the case was reported to CDC.
dNational Notifiable Diseases Surveillance System (NNDSS).
eJurisdictions may report cases of any case status to NNDSS, but only confirmed cases of Legionnaires’ disease from the 50 U.S. states, the District of Columbia, and New York City are included in this figure, with the exceptions noted below. National case counts published in the MMWR use the same criteria and exceptions.
2000, 2002, and 2003: Legionnaires’ disease cases with probable, suspect, and unknown case status were also included.
2001: Legionnaires’ disease cases with probable and unknown case status were also included.
2000–2001: Legionnaires’ disease cases were not reportable in Oregon and West Virginia.
2004–2012: Legionnaires’ disease cases with unknown case status reported from California were also included.
2011–2012: Legionnaires’ disease cases were not reportable in the District of Columbia.

Figure 2. Number of reported confirmed cases of Legionnaires’ diseasea by monthb and yearc—NNDSS,d United States, 2018 and 2019.

Figure 2. Number of reported confirmed cases of Legionnaires’ disease by month and year—NNDSS, United States, 2018 and 2019
aCases of disease due to Legionella are reported to NNDSS as legionellosis, which includes Legionnaires’ disease, Pontiac fever, and extrapulmonary legionellosis, but are referred to as Legionnaires’ disease in this figure (because almost all legionellosis cases reported in the United States are Legionnaires’ disease cases).
bMonth is based upon Morbidity and Mortality Weekly Report year and week (available at https://ndc.services.cdc.gov/wp-content/uploads/2021/02/MMWR_Week_overview.pdf).
cBased on year the case was reported to CDC.
dNational Notifiable Diseases Surveillance System (NNDSS).

Figure 3a. Crude incidencea rates of reported confirmed cases of Legionnaires’ diseaseb by jurisdiction of residencec—NNDSS,d United States, 2018.e,f

Figure 3a. Crude incidencea rates of reported confirmed cases of Legionnaires’ disease by jurisdiction of residence—NNDSS, United States, 2018
aCrude incidence of cases per 100,000 population (number of confirmed Legionnaires' disease cases reported that year divided by postcensal resident jurisdiction population estimate for that year times 100,000 population).
bCases of disease due to Legionella are reported to NNDSS as legionellosis, which includes Legionnaires’ disease, Pontiac fever, and extrapulmonary legionellosis, but are referred to as Legionnaires’ disease in this figure (because almost all legionellosis cases reported in the United States are Legionnaires’ disease cases).
cJurisdiction of the patient’s “usual residence” at the time of disease onset.
dNational Notifiable Diseases Surveillance System (NNDSS).
eBased on year the case was reported to CDC.
fShading represents quintiles of incidence rates.

Figure 3b. Crude incidencea rates of reported confirmed cases of Legionnaires’ diseaseb by jurisdiction of residencec—NNDSS,d United States, 2019.e,f

Figure 3b. Crude incidence rates of reported confirmed cases of Legionnaires’ disease by jurisdiction of residence—NNDSS, United States, 2019
aCrude incidence of cases per 100,000 population (number of confirmed Legionnaires' disease cases reported that year divided by postcensal resident jurisdiction population estimate for that year times 100,000 population).
bCases of disease due to Legionella are reported to NNDSS as legionellosis, which includes Legionnaires’ disease, Pontiac fever, and extrapulmonary legionellosis, but are referred to as Legionnaires’ disease in this figure (because almost all legionellosis cases reported in the United States are Legionnaires’ disease cases).
cJurisdiction of the patient’s “usual residence” at the time of disease onset.
dNational Notifiable Diseases Surveillance System (NNDSS).
eBased on year the case was reported to CDC.
fShading represents quintiles of incidence rates.

Table 1. Number of reported confirmed cases of Legionnaires’ diseasea by jurisdiction of residenceb and yearc—NNDSS,d United States, 2018 and 2019.

Table 1. Number of reported confirmed cases of Legionnaires’ disease by jurisdiction of residence and year—NNDSS, United States, 2018 and 2019.
2018
(Total=9,933)		 2019
(Total=8,890)
Jurisdiction N % N %
ALABAMA 76 0.8 72 0.8
ALASKA 3 0.0 2 0.0
ARIZONA 83 0.8 93 1.1
ARKANSAS 46 0.5 66 0.7
CALIFORNIA 453 4.6 451 5.1
COLORADO 110 1.1 90 1.0
CONNECTICUT 198 2.0 119 1.3
DELAWARE 46 0.5 35 0.4
D.C. 57 0.6 41 0.5
FLORIDA 496 5.0 448 5.0
GEORGIA 181 1.8 171 1.9
HAWAII 17 0.2 11 0.1
IDAHO 15 0.2 25 0.3
ILLINOIS 509 5.1 614 6.9
INDIANA 249 2.5 263 3.0
IOWA 63 0.6 68 0.8
KANSAS 41 0.4 66 0.7
KENTUCKY 146 1.5 121 1.4
LOUISIANA 42 0.4 50 0.6
MAINE 34 0.3 30 0.3
MARYLAND 361 3.6 273 3.1
MASSACHUSETTS 368 3.7 247 2.8
MICHIGAN 633 6.4 551 6.2
MINNESOTA 152 1.5 118 1.3
MISSISSIPPI 41 0.4 47 0.5
MISSOURI 150 1.5 183 2.1
MONTANA 10 0.1 14 0.2
NEBRASKA 43 0.4 46 0.5
NEVADA 16 0.2 25 0.3
NEW HAMPSHIRE 77 0.8 32 0.4
NEW JERSEY 369 3.7 318 3.6
NEW MEXICO 22 0.2 21 0.2
NEW YORK CITY 654 6.6 446 5.0
NEW YORK 770 7.8 606 6.8
NORTH CAROLINA 173 1.7 305 3.4
NORTH DAKOTA 10 0.1 9 0.1
OHIO 930 9.4 785 8.8
OKLAHOMA 63 0.6 52 0.6
OREGON 31 0.3 55 0.6
PENNSYLVANIA 638 6.4 579 6.5
RHODE ISLAND 73 0.7 48 0.5
SOUTH CAROLINA 63 0.6 67 0.8
SOUTH DAKOTA 33 0.3 23 0.3
TENNESSEE 171 1.7 149 1.7
TEXAS 415 4.2 421 4.7
UTAH 33 0.3 38 0.4
VERMONT 17 0.2 12 0.1
VIRGINIA 236 2.4 191 2.2
WASHINGTON 54 0.5 76 0.9
WEST VIRGINIA 129 1.3 82 0.9
WISCONSIN 331 3.3 232 2.6
WYOMING 2 0.0 3 0.0
Total 9,933 100.0 8,890 100.0
aCases of disease due to Legionella are reported to NNDSS as legionellosis, which includes Legionnaires’ disease, Pontiac fever, and extrapulmonary legionellosis, but are referred to as Legionnaires’ disease in this table (because almost all legionellosis cases reported in the United States are Legionnaires’ disease cases).
bJurisdiction of the patient’s “usual residence” at the time of disease onset.
cBased on year the case was reported to CDC.
dNational Notifiable Diseases Surveillance System (NNDSS).

Table 2. Number, percent, and crude incidencea rates of reported confirmed cases of Legionnaires’ diseaseb by demographic characteristics and yearc—NNDSS,d United States, 2018 and 2019.

Table 2. Number, percent, and crude incidencea rates of reported confirmed cases of Legionnaires’ disease by demographic characteristics and year—NNDSS, United States, 2018 and 2019.
Characteristic 2018 2019
N % Ratea N % Ratea
Age
0–9 3 0.0 0.01 12 0.1 0.03
10–19 16 0.2 0.04 17 0.2 0.04
20–29 213 2.1 0.47 164 1.8 0.36
30–39 558 5.6 1.28 478 5.4 1.08
40–49 1,120 11.3 2.77 925 10.4 2.29
50–59 2,308 23.2 5.40 1,990 22.4 4.70
60–69 2,732 27.5 7.31 2,393 26.9 6.30
70–79 1,805 18.2 7.98 1,784 20.1 7.53
80–84 553 5.6 9.03 537 6.0 8.50
85+ 623 6.3 9.53 583 6.6 8.83
Not stated 2 0.0 N/A 7 0.1 N/A
Sex
Female 3,637 36.6 2.19 3,256 36.6 1.95
Male 6,289 63.3 3.91 5,574 62.7 3.45
Not stated 7 0.1 N/A 60 0.7 N/A
Race
American Indian/Alaska Native 49 0.5 1.02 25 0.3 0.52
Asian/Pacific Islander 117 1.2 0.54 159 1.8 0.72
African American/Black 2,251 22.7 4.86 1,763 19.8 3.77
White 6,037 60.8 2.38 5,483 61.7 2.15
Othere 495 5.0 N/A 494 5.6 N/A
Not stated 984 9.9 N/A 966 10.9 N/A
Ethnicity
Hispanic 646 6.5 1.09 588 6.6 0.97
Non-Hispanic 7,110 71.6 2.66 6,376 71.7 2.38
Not stated 2,177 21.9 N/A 1,926 21.7 N/A
Total 9,933 100.0 3.04 8,890 100.0 2.71
aCrude incidence of cases per 100,000 population (number of confirmed Legionnaires' disease cases reported that year divided by postcensal population estimate for that year times 100,000 population).
bCases of disease due to Legionella are reported to NNDSS as legionellosis, which includes Legionnaires’ disease, Pontiac fever, and extrapulmonary legionellosis, but are referred to as Legionnaires’ disease in this table (because almost all legionellosis cases reported in the United States are Legionnaires’ disease cases).
cBased on year the case was reported to CDC.
dNational Notifiable Diseases Surveillance System (NNDSS).
eOther race includes individuals that did not identify with races listed.

Figure 4a. Percent of reported confirmed cases of Legionnaires’ diseasea by age group and yearb—NNDSSc and SLDSS,d United States, 2018 and 2019.

Figure 4a. Percent of reported confirmed cases of Legionnaires’ disease by age group and year—NNDSS and SLDSS, United States, 2018 and 2019
aCases of disease due to Legionella are reported to NNDSS as legionellosis, which includes Legionnaires’ disease, Pontiac fever, and extrapulmonary legionellosis, but are referred to as Legionnaires’ disease in this figure (because almost all legionellosis cases reported in the United States are Legionnaires’ disease cases). SLDSS data are limited to cases of Legionnaires’ disease in this figure.
bBased on year the case was reported to CDC in NNDSS and year of symptom onset in SLDSS. If onset date was not stated in SLDSS, case year for confirmed cases was determined by the following dates (in order of reporting): positive laboratory date (by either urinary antigen testing, culture, or 4-fold rise of antibody titer against Legionella pneumophila serogroup 1); date patient was hospitalized during treatment for Legionnaires’ disease; or date case was first reported to public health at any level.
cNational Notifiable Diseases Surveillance System (NNDSS).
dSupplemental Legionnaires’ Disease Surveillance System (SLDSS).

Figure 4b. Percent of reported confirmed cases of Legionnaires’ diseasea by sex and yearb—NNDSSc and SLDSS,d United States, 2018 and 2019.

Figure 4b. Percent of reported confirmed cases of Legionnaires’ disease by sex and year—NNDSS and SLDSS, United States, 2018 and 2019
aCases of disease due to Legionella are reported to NNDSS as legionellosis, which includes Legionnaires’ disease, Pontiac fever, and extrapulmonary legionellosis, but are referred to as Legionnaires’ disease in this figure (because almost all legionellosis cases reported in the United States are Legionnaires’ disease cases). SLDSS data are limited to cases of Legionnaires’ disease in this figure.
bBased on year the case was reported to CDC in NNDSS and year of symptom onset in SLDSS. If onset date was not stated in SLDSS, case year for confirmed cases was determined by the following dates (in order of reporting): positive laboratory date (by either urinary antigen testing, culture, or 4-fold rise of antibody titer against Legionella pneumophila serogroup 1); date patient was hospitalized during treatment for Legionnaires’ disease; or date case was first reported to public health at any level.
cNational Notifiable Diseases Surveillance System (NNDSS).
dSupplemental Legionnaires’ Disease Surveillance System (SLDSS).

Figure 4c. Percent of reported confirmed cases of Legionnaires’ diseasea by raceb and yearc—NNDSSd and SLDSS,e United States, 2018 and 2019.

Figure 4c. Percent of reported confirmed cases of Legionnaires’ disease by race and year—NNDSS and SLDSS, United States, 2018 and 2019
aCases of disease due to Legionella are reported to NNDSS as legionellosis, which includes Legionnaires’ disease, Pontiac fever, and extrapulmonary legionellosis, but are referred to as Legionnaires’ disease in this figure (because almost all legionellosis cases reported in the United States are Legionnaires’ disease cases). SLDSS data are limited to cases of Legionnaires’ disease in this figure.
bIn NNDSS, Other includes American Indian/Alaska Native, Asian/Pacific Islander, and individuals that did not identify with either race in NNDSS. In SLDSS, Other includes American Indian/Alaska Native, Asian, Hawaii/Pacific Islander, and individuals that identified with multiple races.
cBased on year the case was reported to CDC in NNDSS and year of symptom onset in SLDSS. If onset date was not stated in SLDSS, case year for confirmed cases was determined by the following dates (in order of reporting): positive laboratory date (by either urinary antigen testing, culture, or 4-fold rise of antibody titer against Legionella pneumophila serogroup 1); date patient was hospitalized during treatment for Legionnaires’ disease; or date case was first reported to public health at any level.
dNational Notifiable Diseases Surveillance System (NNDSS).
eSupplemental Legionnaires’ Disease Surveillance System (SLDSS).

Figure 4d. Percent of reported confirmed cases of Legionnaires’ diseasea by ethnicity and yearb—NNDSSc and SLDSS,d United States, 2018 and 2019.

Figure 4d. Percent of reported confirmed cases of Legionnaires’ disease by ethnicity and year—NNDSS and SLDSS, United States, 2018 and 2019
aCases of disease due to Legionella are reported to NNDSS as legionellosis, which includes Legionnaires’ disease, Pontiac fever, and extrapulmonary legionellosis, but are referred to as Legionnaires’ disease in this figure (because almost all legionellosis cases reported in the United States are Legionnaires’ disease cases). SLDSS data are limited to cases of Legionnaires’ disease in this figure.
bBased on year the case was reported to CDC in NNDSS and year of symptom onset in SLDSS. If onset date was not stated in SLDSS, case year for confirmed cases was determined by the following dates (in order of reporting): positive laboratory date (by either urinary antigen testing, culture, or 4-fold rise of antibody titer against Legionella pneumophila serogroup 1); date patient was hospitalized during treatment for Legionnaires’ disease; or date case was first reported to public health at any level.
cNational Notifiable Diseases Surveillance System (NNDSS).
dSupplemental Legionnaires’ Disease Surveillance System (SLDSS).

Figure 5a. Reported confirmed cases of legionellosisa by syndrome and completeness of jurisdictional reportingb—SLDSS,c United States, 2018.d

Figure 5a. Reported confirmed cases of legionellosis by syndrome and completeness of jurisdictional reporting—SLDSS, United States, 2018

aLegionellosis includes Legionnaires’ disease, Pontiac fever, and extrapulmonary legionellosis.
b42 complete reporting jurisdictions reported at least 90% of confirmed NNDSS cases to SLDSS in 2018: Alabama, Alaska, Arizona, Arkansas, California, Colorado, Connecticut, Delaware, District of Columbia, Florida, Georgia, Hawaii,  Illinois, Indiana, Iowa, Kansas, Kentucky, Maine, Maryland, Michigan, Minnesota, Mississippi, Missouri, Nebraska, New Hampshire, New York (state), New York City, North Carolina, North Dakota, Ohio, Oregon, Pennsylvania, Rhode Island, South Carolina, Tennessee, Texas, Utah, Vermont, Virginia, Washington, Wisconsin, and Wyoming.
cSupplemental Legionnaires’ Disease Surveillance System (SLDSS).
dBased on year of symptom onset in SLDSS. If onset date was not stated in SLDSS, case year for confirmed cases was determined by the following dates (in order of reporting): positive laboratory date (by either urinary antigen testing, culture, or 4-fold rise of antibody titer against Legionella pneumophila serogroup 1); date patient was hospitalized during treatment for Legionnaires’ disease; or date case was first reported to public health at any level.
eLegionnaires’ disease.
fCFR: Case fatality rate calculated as the number of reported confirmed case deaths divided by the number of patients with the same legionellosis syndrome.
gPontiac fever.
hExtrapulmonary legionellosis.
iWhile legionellosis consists of Legionnaires’ disease, Pontiac fever, and extrapulmonary legionellosis, syndrome was not specified for some cases.
jComplete reporting.

Figure 5b. Reported confirmed cases of legionellosisa by syndrome and completeness of jurisdictional reportingb—SLDSS,c United States, 2019.d

Figure 5b. Reported confirmed cases of legionellosis by syndrome and completeness of jurisdictional reporting—SLDSS, United States, 2019

aLegionellosis includes Legionnaires’ disease, Pontiac fever, and extrapulmonary legionellosis.
b38 complete reporting jurisdictions reported at least 90% of confirmed NNDSS cases to SLDSS in 2019: Alabama, Alaska, Arizona, California, Colorado, Connecticut, Delaware, District of Columbia, Florida, Georgia, Hawaii, Idaho, Illinois, Indiana, Iowa, Kansas, Kentucky, Maine, Michigan, Minnesota, Missouri, Montana, Nebraska, Nevada, New Hampshire, New York (state), New York City, Ohio, Oregon, Pennsylvania, Rhode Island, Tennessee, Texas, Utah, Vermont, Virginia, Washington, and Wyoming.
cSupplemental Legionnaires’ Disease Surveillance System (SLDSS).
dBased on year of symptom onset in SLDSS. If onset date was not stated in SLDSS, case year for confirmed cases was determined by the following dates (in order of reporting): positive laboratory date (by either urinary antigen testing, culture, or 4-fold rise of antibody titer against Legionella pneumophila serogroup 1); date patient was hospitalized during treatment for Legionnaires’ disease; or date case was first reported to public health at any level.
eLegionnaires’ disease.
fCFR: Case fatality rate calculated as the number of reported confirmed case deaths divided by the number of patients with the same legionellosis syndrome.
gPontiac fever.
hExtrapulmonary legionellosis.
iWhile legionellosis consists of Legionnaires’ disease, Pontiac fever, and extrapulmonary legionellosis, syndrome was not specified for some cases.
jComplete reporting.

Figure 6a. Number of reported confirmed cases and deaths of Legionnaires’ disease by exposure categorya—SLDSS,b complete reporting jurisdictions,c 2018.d

Figure 6a. Number of reported confirmed cases and deaths of Legionnaires’ disease by exposure categorya—SLDSS, complete reporting jurisdictions, 2018
Cases Deaths
N % N CFRe
Exposure category (Total = 8,764) (Total= 719)
Any Healthcare 1,584 18.1 156 9.8
Definite Healthcare 204 2.3 53 26.0
Possible Healthcare 1,380 15.7 103 7.5
Any Travel 1,279 14.6 35 2.7
Any Assisted or senior living 326 3.7 30 9.2
None of these 5,886 67.2 342 5.8
Figure 6a. Number of reported confirmed cases and deaths of Legionnaires’ disease by exposure category—SLDSS, complete reporting jurisdictions, 2018
aExposure categories are not mutually exclusive. A patient may report multiple exposures in the 10 days before date of symptom onset. Exposure categories:
Healthcare: A patient who visited, worked, or stayed in a healthcare setting in the 10 days before date of symptom onset.
Travel: A patient with a history of spending at least one night away from home (in the state of residence, another state, or another country) in the 10 days before date of symptom onset, not including nights spent in a healthcare facility.
Assisted or senior living facility: A patient who visited, worked, or stayed in a senior or assisted living facility in the 10 days before date of symptom onset.
None of these: A patient without reported healthcare setting, travel, or senior or assisted living facility exposure in the 10 days before date of symptom onset.
bSupplemental Legionnaires’ Disease Surveillance System (SLDSS).
cComplete reporting jurisdictions in 2018: 42 complete reporting jurisdictions reported at least 90% of confirmed NNDSS cases to SLDSS: Alabama, Alaska, Arizona, Arkansas, California, Colorado, Connecticut, Delaware, District of Columbia, Florida, Georgia, Hawaii, Illinois, Indiana, Iowa, Kansas, Kentucky, Maine, Maryland, Michigan, Minnesota, Mississippi, Missouri, Nebraska, New Hampshire, New York (state), New York City, North Carolina, North Dakota, Ohio, Oregon, Pennsylvania, Rhode Island, South Carolina, Tennessee, Texas, Utah, Vermont, Virginia, Washington, Wisconsin, and Wyoming.
dBased on year of symptom onset in SLDSS. If onset date was not stated in SLDSS, case year for confirmed cases was determined by the following dates (in order of reporting): positive laboratory date (by either urinary antigen testing, culture, or 4-fold rise of antibody titer against Legionella pneumophila serogroup 1); date patient was hospitalized during treatment for Legionnaires’ disease; or date case was first reported to public health at any level.
eCFR: Case fatality rate calculated as the number of reported confirmed Legionnaires’ disease case deaths divided by the number of patients with Legionnaires' disease and the same exposure history.

Figure 6b. Number of reported confirmed cases and deaths of Legionnaires’ disease by exposure categorya—SLDSS,b complete reporting jurisdictions,c 2019.d

Figure 6b. Number of reported confirmed cases and deaths of Legionnaires’ disease by exposure category—SLDSS, complete reporting jurisdictions, 2019
Cases Deaths
N % N CFRe
Exposure category (Total = 6,955) (Total= 639)
Any Healthcare 1,284 18.5 134 10.4
Definite Healthcare 192 2.8 41 21.4
Possible Healthcare 1,092 15.7 93 8.5
Any Travel 1,156 16.6 35 3.0
Any Assisted or senior living 203 2.9 25 12.3
None of these 4,559 65.5 311 6.8
Figure 6b. Number of reported confirmed cases and deaths of Legionnaires’ disease by exposure category—SLDSS, complete reporting jurisdictions, 2019
aExposure categories are not mutually exclusive. A patient may report multiple exposures in the 10 days before date of symptom onset. Exposure categories:
Healthcare: A patient who visited, worked, or stayed in a healthcare setting in the 10 days before date of symptom onset.
Travel: A patient with a history of spending at least one night away from home (in the state of residence, another state, or another country) in the 10 days before date of symptom onset, not including nights spent in a healthcare facility.
Assisted or senior living facility: A patient who visited, worked, or stayed in a senior or assisted living facility in the 10 days before date of symptom onset.
None of these: A patient without reported healthcare setting, travel, or senior or assisted living facility exposure in the 10 days before date of symptom onset.
bSupplemental Legionnaires’ Disease Surveillance System (SLDSS).
cComplete reporting jurisdictions for 2019: 38 complete reporting jurisdictions reported at least 90% of confirmed NNDSS cases to SLDSS in 2019: Alabama, Alaska, Arizona, California, Colorado, Connecticut, Delaware, District of Columbia, Florida, Georgia, Hawaii, Idaho, Illinois, Indiana, Iowa, Kansas, Kentucky, Maine, Michigan, Minnesota, Missouri, Montana, Nebraska, Nevada, New Hampshire, New York (state), New York City, Ohio, Oregon, Pennsylvania, Rhode Island, Tennessee, Texas, Utah, Vermont, Virginia, Washington, and Wyoming.
dBased on year of symptom onset in SLDSS. If onset date was not stated in SLDSS, case year for confirmed cases was determined by the following dates (in order of reporting): positive laboratory date (by either urinary antigen testing, culture, or 4-fold rise of antibody titer against Legionella pneumophila serogroup 1); date patient was hospitalized during treatment for Legionnaires’ disease; or date case was first reported to public health at any level.
eCFR: Case fatality rate calculated as the number of reported confirmed Legionnaires’ disease case deaths divided by the number of patients with Legionnaires' disease and the same exposure history.

Table 3. Number of reported confirmed cases of Legionnaires’ disease by exposure categorya and yearb—SLDSS,c complete reporting jurisdictions,d 2018 and 2019.

Table 3. Number of reported confirmed cases of Legionnaires’ disease by exposure category and year—SLDSS, complete reporting jurisdictions, 2018 and 2019.
2018
(Total = 8,764)		 2019
(Total = 6,955)
Exposure category N % N %
Healthcare 1,584 18.1 1,284 18.5
Healthcare facility type
Hospital 497 31.4 463 36.1
Long-term care facility 296 18.7 206 16.0
Clinic 520 32.8 381 29.7
Multiple 141 8.9 154 12.0
Other 11 0.7 35 2.7
Not stated 119 7.5 45 3.5
Healthcare exposure type
Inpatient 377 23.8 354 27.6
Outpatient 738 46.6 541 42.1
Visitor 184 11.6 132 10.3
Employee 126 8.0 98 7.6
Multiple 95 6.0 91 7.1
Not stated 64 4.0 68 5.3
Travel 1,279 14.6 1,156 16.6
Any public accommodation 818 64.0 765 66.2
Hotel/motel/resort 804 752
Cruise ship 30 20
All private accommodations 354 27.7 261 22.6
Unknown travel accommodation type 107 8.4 130 11.2
Assisted or senior living 326 3.7 203 2.9
Assisted or senior living facility type
Assisted living facility 202 62.0 101 49.8
Senior living facility 102 31.3 76 37.4
Both 5 1.5 5 2.5
Not stated 17 5.2 21 10.3
Assisted or senior living exposure type
Resident 192 58.9 116 57.1
Visitor 79 24.2 47 23.2
Employee 39 12.0 18 8.9
Multiple 1 0.3 1 0.5
Not stated 15 4.6 21 10.3
None of these 5,886 67.2 4,559 65.5
aExposure categories (categories are not mutually exclusive):
Healthcare: A patient who visited, worked, or stayed in a healthcare setting in the 10 days before date of symptom onset.
Travel: A patient with a history of spending at least one night away from home (in the state of residence, another state, or another country) in the 10 days before date of symptom onset, not including nights spent in a healthcare facility. Cases may occur in patients with multiple travel locations during the exposure period. If any exposure to a public accommodation occurs, the case is categorized as public travel. Private travel represents exposure to private accommodations only. If a patient has exposure to both private and unknown accommodations, the case is categorized as unknown travel.
Assisted or senior living: A patient who visited, worked, or stayed in a senior or assisted living facility in the 10 days before date of symptom onset.
None of these: A patient without reported healthcare setting, travel, or senior or assisted living facility exposure in the 10 days before date of symptom onset.
bBased on year of symptom onset in SLDSS. If onset date was not stated in SLDSS, case year for confirmed cases was determined by the following dates (in order of reporting): positive laboratory date (by either urinary antigen testing, culture, or fourfold rise of antibody titer against Legionella pneumophila serogroup 1); date patient was hospitalized during treatment for Legionnaires’ disease; or date case was first reported to public health at any level.
cSupplemental Legionnaires’ Disease Surveillance System (SLDSS).
dComplete reporting jurisdictions in 2018: 42 complete reporting jurisdictions reported at least 90% of confirmed NNDSS cases to SLDSS: Alabama, Alaska, Arizona, Arkansas, California, Colorado, Connecticut, Delaware, District of Columbia, Florida, Georgia, Hawaii, Illinois, Indiana, Iowa, Kansas, Kentucky, Maine, Maryland, Michigan, Minnesota, Mississippi, Missouri, Nebraska, New Hampshire, New York (state), New York City, North Carolina, North Dakota, Ohio, Oregon, Pennsylvania, Rhode Island, South Carolina, Tennessee, Texas, Utah, Vermont, Virginia, Washington, Wisconsin, and Wyoming.
Complete reporting jurisdictions for 2019: 38 complete reporting jurisdictions reported at least 90% of confirmed NNDSS cases to SLDSS in 2019: Alabama, Alaska, Arizona, California, Colorado, Connecticut, Delaware, District of Columbia, Florida, Georgia, Hawaii, Idaho, Illinois, Indiana, Iowa, Kansas, Kentucky, Maine, Michigan, Minnesota, Missouri, Montana, Nebraska, Nevada, New Hampshire, New York (state), New York City, Ohio, Oregon, Pennsylvania, Rhode Island, Tennessee, Texas, Utah, Vermont, Virginia, Washington, and Wyoming.

Table 4a. Number of reported confirmed cases of Legionnaires’ disease by demographic characteristics and exposure categorya—SLDSS,b complete reporting jurisdictions,c 2018.d

Table 4a. Number of reported confirmed cases of Legionnaires’ disease by demographic characteristics and exposure category—SLDSS, complete reporting jurisdictions, 2018.
Exposure category
Healthcare
(Total =1,584)		 Travel
(Total = 1,279)		 Assisted or senior living
(Total = 326)		 None of these
(Total = 5,886)
Characteristic N % N % N % N %
Median Age (years) 65 62 71 61
Age
0–9 0 0.0 0 0.0 0 0.0 2 0.0
10–19 2 0.1 3 0.2 0 0.0 10 0.2
20–29 19 1.2 24 1.9 4 1.2 151 2.6
30–39 65 4.1 76 5.9 8 2.5 384 6.5
40–49 134 8.5 152 11.9 19 5.8 714 12.1
50–59 311 19.6 287 22.4 49 15.0 1,444 24.5
60–69 447 28.2 377 29.5 72 22.1 1,576 26.8
70–79 356 22.5 263 20.6 74 22.7 964 16.4
80–84 109 6.9 58 4.5 29 8.9 301 5.1
85+ 141 8.9 35 2.7 71 21.8 313 5.3
Not stated 0 0.0 4 0.3 0 0.0 27 0.5
Sex
Female 670 42.3 443 34.6 163 50.0 2,000 34.0
Male 908 57.3 828 64.7 160 49.1 3,815 64.8
Not stated 6 0.4 8 0.6 3 0.9 71 1.2
Race
American Indian/Alaska Native 8 0.5 4 0.3 1 0.3 29 0.5
Asian 17 1.1 9 0.7 0 0.0 68 1.2
Black or African American 376 23.7 226 17.7 75 23.0 1,548 26.3
Native Hawaiian/Other Pacific Islander 2 0.1 2 0.2 0 0.0 7 0.1
White 1,010 63.8 855 66.8 223 68.4 3,472 59.0
Multiple 2 0.1 2 0.2 0 0.0 8 0.1
Not stated 169 10.7 181 14.2 27 8.3 754 12.8
Ethnicity
Hispanic 88 5.6 71 5.6 15 4.6 433 7.4
Non-Hispanic 1,196 75.5 935 73.1 258 79.1 4,314 73.3
Not stated 300 18.9 273 21.3 53 16.3 1,139 19.4
aExposure categories (categories are not mutually exclusive):
Healthcare: A patient who visited, worked, or stayed in a healthcare setting in the 10 days before date of symptom onset.
Travel: A patient with a history of spending at least one night away from home (in the state of residence, another state, or another country) in the 10 days before date of symptom onset, not including nights spent in a healthcare facility.
Assisted or senior living: A patient who visited, worked, or stayed in a senior or assisted living facility in the 10 days before date of symptom onset.
None of these: A patient without reported healthcare setting, travel, or senior or assisted living facility exposure in the 10 days before date of symptom onset.
bSupplemental Legionnaires’ Disease Surveillance System (SLDSS).
cComplete reporting jurisdictions in 2018: 42 complete reporting jurisdictions reported at least 90% of confirmed NNDSS cases to SLDSS in 2018: Alabama, Alaska, Arizona, Arkansas, California, Colorado, Connecticut, Delaware, District of Columbia, Florida, Georgia, Hawaii, Illinois, Indiana, Iowa, Kansas, Kentucky, Maine, Maryland, Michigan, Minnesota, Mississippi, Missouri, Nebraska, New Hampshire, New York (state), New York City, North Carolina, North Dakota, Ohio, Oregon, Pennsylvania, Rhode Island, South Carolina, Tennessee, Texas, Utah, Vermont, Virginia, Washington, Wisconsin, and Wyoming.
dBased on year of symptom onset in SLDSS. If onset date was not stated in SLDSS, case year for confirmed cases was determined by the following dates (in order of reporting): positive laboratory date (by either urinary antigen testing, culture, or 4-fold rise of antibody titer against Legionella pneumophila serogroup 1); date patient was hospitalized during treatment for Legionnaires’ disease; or date case was first reported to public health at any level.

Table 4b. Number of reported confirmed cases of Legionnaires’ disease by demographic characteristics and exposure categorya—SLDSS,b complete reporting jurisdictions,c 2019.d

Table 4b. Number of reported confirmed cases of Legionnaires’ disease by demographic characteristics and exposure category—SLDSS, complete reporting jurisdictions, 2019.
Exposure category
Healthcare
(Total = 1,284)		 Travel
(Total = 1,156)		 Assisted or senior living
(Total = 203)		 None of these
(Total = 4,559)
Characteristic N % N % N % N %
Median Age (years) 66 61 73 62
Age
0–9 0 0.0 1 0.1 0 0.0 2 0.0
10–19 3 0.2 3 0.3 0 0.0 5 0.1
20–29 19 1.5 20 1.7 3 1.5 83 1.8
30–39 47 3.7 74 6.4 1 0.5 278 6.1
40–49 98 7.6 148 12.8 13 6.4 495 10.9
50–59 233 18.1 259 22.4 30 14.8 1,046 22.9
60–69 337 26.2 340 29.4 42 20.7 1,212 26.6
70–79 313 24.4 220 19.0 39 19.2 899 19.7
80–84 91 7.1 52 4.5 23 11.3 275 6.0
85+ 142 11.1 32 2.8 52 25.6 253 5.5
Not stated 1 0.1 7 0.6 0 0.0 11 0.2
Sex
Female 580 45.2 415 35.9 103 50.7 1,575 34.5
Male 696 54.2 730 63.1 99 48.8 2,956 64.8
Not stated 8 0.6 11 1.0 1 0.5 28 0.6
Race
American Indian/Alaska Native 4 0.3 2 0.2 1 0.5 10 0.2
Asian 20 1.6 16 1.4 2 1.0 64 1.4
Black or African American 235 18.3 170 14.7 31 15.3 1,014 22.2
Native Hawaiian/Other Pacific Islander 1 0.1 0 0.0 1 0.5 9 0.2
White 874 68.1 771 66.7 150 73.9 2,860 62.7
Multiple 1 0.1 3 0.3 0 0.0 5 0.1
Not stated 149 11.6 194 16.8 18 8.9 597 13.1
Ethnicity
Hispanic 85 6.6 88 7.6 12 5.9 386 8.5
Non-Hispanic 952 74.1 820 70.9 149 73.4 3,196 70.1
Not stated 247 19.2 248 21.5 42 20.7 977 21.4
aExposure categories (categories are not mutually exclusive):
Healthcare: A patient who visited, worked, or stayed in a healthcare setting in the 10 days before date of symptom onset.
Travel: A patient with a history of spending at least one night away from home (in the state of residence, another state, or another country) in the 10 days before date of symptom onset, not including nights spent in a healthcare facility.
Assisted or senior living: A patient who visited, worked, or stayed in a senior or assisted living facility in the 10 days before date of symptom onset.
None of these: A patient without reported healthcare setting, travel, or senior or assisted living facility exposure in the 10 days before date of symptom onset.
bSupplemental Legionnaires’ Disease Surveillance System (SLDSS).
cComplete reporting jurisdictions for 2019: 38 complete reporting jurisdictions reported at least 90% of confirmed NNDSS cases to SLDSS in 2019: Alabama, Alaska, Arizona, California, Colorado, Connecticut, Delaware, District of Columbia, Florida, Georgia, Hawaii, Idaho, Illinois, Indiana, Iowa, Kansas, Kentucky, Maine, Michigan, Minnesota, Missouri, Montana, Nebraska, Nevada, New Hampshire, New York (state), New York City, Ohio, Oregon, Pennsylvania, Rhode Island, Tennessee, Texas, Utah, Vermont, Virginia, Washington, and Wyoming.
dBased on year of symptom onset in SLDSS. If onset date was not stated in SLDSS, case year for confirmed cases was determined by the following dates (in order of reporting): positive laboratory date (by either urinary antigen testing, culture, or 4-fold rise of antibody titer against Legionella pneumophila serogroup 1); date patient was hospitalized during treatment for Legionnaires’ disease; or date case was first reported to public health at any level.

Table 5a. Number of reported confirmed cases of healthcare-associateda Legionnaires’ disease by healthcare facility type and healthcare exposure certaintyb—SLDSS,c complete reporting jurisdictions,d 2018.e

Table 5a. Number of reported confirmed cases of healthcare-associated Legionnaires’ disease by healthcare facility type and healthcare exposure certainty—SLDSS, complete reporting jurisdictions, 2018.
Healthcare exposure certainty
Definite Possible Total
Facility type N % N % N %
Hospital 38 18.6 459 33.3 497 31.4
Long-term care facility 128 62.7 168 12.2 296 18.7
Clinic 1 0.5 519 37.6 520 32.8
Multiplef 33 16.2 108 7.8 141 8.9
Otherg 1 0.5 10 0.7 11 0.7
Not stated 3 1.5 116 8.4 119 7.5
Total 204 100 1,380 100 1,584 100
aHealthcare–associated Legionnaires’ disease includes both definite and possible cases in patients who worked, visited, or stayed in a healthcare setting for any amount of time in the 10 days preceding symptom onset.
bHealthcare exposure certainty defined as:
Definite case of healthcare–associated Legionnaires’ disease was defined as laboratory-confirmed legionellosis in a patient with exposure to a hospital or long-term–care facility for the entire 10 days preceding symptom onset.
Possible case of healthcare–associated Legionnaires’ disease was defined as laboratory-confirmed legionellosis in a patient with exposure to a healthcare facility for a portion of the 10 days preceding symptom onset.
cSupplemental Legionnaires’ Disease Surveillance System (SLDSS).
dComplete reporting jurisdictions in 2018: 42 complete reporting jurisdictions reported at least 90% of confirmed NNDSS cases to SLDSS in 2018: Alabama, Alaska, Arizona, Arkansas, California, Colorado, Connecticut, Delaware, District of Columbia, Florida, Georgia, Hawaii, Illinois, Indiana, Iowa, Kansas, Kentucky, Maine, Maryland, Michigan, Minnesota, Mississippi, Missouri, Nebraska, New Hampshire, New York (state), New York City, North Carolina, North Dakota, Ohio, Oregon, Pennsylvania, Rhode Island, South Carolina, Tennessee, Texas, Utah, Vermont, Virginia, Washington, Wisconsin, and Wyoming.
eBased on year of symptom onset in SLDSS. If onset date was not stated in SLDSS, case year for confirmed cases was determined by the following dates (in order of reporting): positive laboratory date (by either urinary antigen testing, culture, or 4-fold rise of antibody titer against Legionella pneumophila serogroup 1); date patient was hospitalized during treatment for Legionnaires’ disease; or date case was first reported to public health at any level.
fMultiple indicates more than one type of healthcare facility.
gOther facility includes locations such as outpatient laboratories and pharmacies.

Table 5b. Number of reported confirmed cases of healthcare-associateda Legionnaires’ disease by healthcare facility type and healthcare exposure certaintyb—SLDSS,c complete reporting jurisdictions,d 2019.e

Table 5b. Number of reported confirmed cases of healthcare-associated Legionnaires’ disease by healthcare facility type and healthcare exposure certainty—SLDSS, complete reporting jurisdictions, 2019.
Healthcare exposure certainty
Definite Possible Total
Facility type N % N % N %
Hospital 36 18.8 427 39.1 463 36.1
Long-term care facility 95 49.5 111 10.2 206 16.0
Clinic 5 2.6 376 34.4 381 29.7
Multiplef 39 20.3 115 10.5 154 12.0
Otherg 3 1.6 32 2.9 35 2.7
Not stated 14 7.3 31 2.8 45 3.5
Total 192 100 1,092 100 1,284 100
aHealthcare–associated Legionnaires’ disease includes both definite and possible cases in patients who worked, visited, or stayed in a healthcare setting for any amount of time in the 10 days preceding symptom onset.
bHealthcare exposure certainty defined as:
Definite case of healthcare–associated Legionnaires’ disease was defined as laboratory-confirmed legionellosis in a patient with exposure to a hospital or long-term–care facility for the entire 10 days preceding symptom onset.
Possible case of healthcare–associated Legionnaires’ disease was defined as laboratory-confirmed legionellosis in a patient with exposure to a healthcare facility for a portion of the 10 days preceding symptom onset.
cSupplemental Legionnaires’ Disease Surveillance System (SLDSS).
dComplete reporting jurisdictions for 2019: 38 complete reporting jurisdictions reported at least 90% of confirmed NNDSS cases to SLDSS in 2019: Alabama, Alaska, Arizona, California, Colorado, Connecticut, Delaware, District of Columbia, Florida, Georgia, Hawaii, Idaho, Illinois, Indiana, Iowa, Kansas, Kentucky, Maine, Michigan, Minnesota, Missouri, Montana, Nebraska, Nevada, New Hampshire, New York (state), New York City, Ohio, Oregon, Pennsylvania, Rhode Island, Tennessee, Texas, Utah, Vermont, Virginia, Washington, and Wyoming.
eBased on year of symptom onset in SLDSS. If onset date was not stated in SLDSS, case year for confirmed cases was determined by the following dates (in order of reporting): positive laboratory date (by either urinary antigen testing, culture, or 4-fold rise of antibody titer against Legionella pneumophila serogroup 1); date patient was hospitalized during treatment for Legionnaires’ disease; or date case was first reported to public health at any level.
fMultiple indicates more than one type of healthcare facility.
gOther facility includes locations such as outpatient laboratories and pharmacies.

Table 6a. Number of reported confirmed cases of Legionnaires’ disease by hospitalization,a outcome,b and exposure categoryc—SLDSS,d complete reporting jurisdictions,e 2018.f

Table 6a. Number of reported confirmed cases of Legionnaires’ disease by hospitalization, outcome, and exposure category—SLDSS, complete reporting jurisdictions, 2018.
Exposure category
Healthcare
(Total =1,584)		 Travel
(Total = 1,279)		 Assisted or senior living
(Total = 326)		 None of these
(Total = 5,886)
N % N % N % N %
Hospitalization
Yes 1,526 96.3 1,226 95.9 308 94.5 5,633 95.7
No 55 3.5 30 2.3 15 4.6 131 2.2
Not stated 3 0.2 23 1.8 3 0.9 122 2.1
Outcome
Death 156 9.8 35 2.7 30 9.2 342 5.8
Still ill 111 7.0 44 3.4 21 6.4 335 5.7
Survived 1,222 77.1 1,139 89.1 259 79.4 4,801 81.6
Not stated 95 6.0 61 4.8 16 4.9 408 6.9
aHospitalization for treatment of Legionnaires’ disease.
bOutcome at time of case reporting.
cExposure categories (categories are not mutually exclusive):
Healthcare: Legionnaires' disease in a patient who visited, worked, or stayed in a healthcare setting in the 10 days before date of symptom onset.
Travel: Legionnaires' disease in a patient with a history of spending at least one night away from home (in the state of residence, another state, or another country) in the 10 days before date of symptom onset, not including nights spent in a healthcare facility.
Assisted or senior living: Legionnaires' disease in a patient who visited, worked, or stayed in a senior or assisted living facility in the 10 days before date of symptom onset.
None of these: A patient without reported healthcare setting, travel, or senior or assisted living facility exposure in the 10 days before date of symptom onset.
dSupplemental Legionnaires’ Disease Surveillance System (SLDSS).
eComplete reporting jurisdictions in 2018: 42 complete reporting jurisdictions reported at least 90% of confirmed NNDSS cases to SLDSS in 2018: Alabama, Alaska, Arizona, Arkansas, California, Colorado, Connecticut, Delaware, District of Columbia, Florida, Georgia, Hawaii, Illinois, Indiana, Iowa, Kansas, Kentucky, Maine, Maryland, Michigan, Minnesota, Mississippi, Missouri, Nebraska, New Hampshire, New York (state), New York City, North Carolina, North Dakota, Ohio, Oregon, Pennsylvania, Rhode Island, South Carolina, Tennessee, Texas, Utah, Vermont, Virginia, Washington, Wisconsin, and Wyoming.
fBased on year of symptom onset in SLDSS. If onset date was not stated in SLDSS, case year for confirmed cases was determined by the following dates (in order of reporting): positive laboratory date (by either urinary antigen testing, culture, or 4-fold rise of antibody titer against Legionella pneumophila serogroup 1); date patient was hospitalized during treatment for Legionnaires’ disease; or date case was first reported to public health at any level.

Table 6b. Number of reported confirmed cases of Legionnaires’ disease by hospitalization,a outcome,b and exposure categoryc—SLDSS,d complete reporting jurisdictions,e 2019.f

Table 6b. Number of reported confirmed cases of Legionnaires’ disease by hospitalization, outcome, and exposure category—SLDSS, complete reporting jurisdictions, 2019.
Exposure category
Healthcare
(Total = 1,284)		 Travel
(Total = 1,156)		 Assisted or senior living
(Total = 203)		 None of these
(Total = 4,559)
N % N % N % N %
Hospitalization
Yes 1,231 95.9 1,075 93.0 194 95.6 4,379 96.1
No 43 3.3 29 2.5 7 3.4 116 2.5
Not stated 10 0.8 52 4.5 2 1.0 64 1.4
Outcome
Death 134 10.4 35 3.0 25 12.3 311 6.8
Still ill 46 3.6 25 2.2 10 4.9 99 2.2
Survived 1,047 81.5 1,032 89.3 161 79.3 3,837 84.2
Not stated 57 4.4 64 5.5 7 3.4 312 6.8
aHospitalization for treatment of Legionnaires’ disease.
bOutcome at time of case reporting.
cExposure categories (categories are not mutually exclusive):
Healthcare: Legionnaires' disease in a patient who visited, worked, or stayed in a healthcare setting in the 10 days before date of symptom onset.
Travel: Legionnaires' disease in a patient with a history of spending at least one night away from home (in the state of residence, another state, or another country) in the 10 days before date of symptom onset, not including nights spent in a healthcare facility.
Assisted or senior living: Legionnaires' disease in a patient who visited, worked, or stayed in a senior or assisted living facility in the 10 days before date of symptom onset.
None of these: A patient without reported healthcare setting, travel, or senior or assisted living facility exposure in the 10 days before date of symptom onset.
dSupplemental Legionnaires’ Disease Surveillance System (SLDSS).
eComplete  reporting jurisdictions for 2019: 38 complete reporting jurisdictions reported at least 90% of confirmed NNDSS cases to SLDSS in 2019: Alabama, Alaska, Arizona, California, Colorado, Connecticut, Delaware, District of Columbia, Florida, Georgia, Hawaii, Idaho, Illinois, Indiana, Iowa, Kansas, Kentucky, Maine, Michigan, Minnesota, Missouri, Montana, Nebraska, Nevada, New Hampshire, New York (state), New York City, Ohio, Oregon, Pennsylvania, Rhode Island, Tennessee, Texas, Utah, Vermont, Virginia, Washington, and Wyoming.
fBased on year of symptom onset in SLDSS. If onset date was not stated in SLDSS, case year for confirmed cases was determined by the following dates (in order of reporting): positive laboratory date (by either urine antigen testing, culture, or 4-fold rise of antibody titer against Legionella pneumophila serogroup 1); date patient was hospitalized during treatment for Legionnaires’ disease; or date case was first reported to public health at any level.

Figure 7. Percent of reported confirmed cases of Legionnaires’ disease that were treated in hospitala by age group and yearb—SLDSS,c complete reporting jurisdictions,d 2018 and 2019.

Figure 7. Percent of reported confirmed cases of Legionnaires’ disease that were treated in hospital by age group and year—SLDSS, complete reporting jurisdictions, 2018 and 2019

aHospitalization for treatment of Legionnaires’ disease.
bBased on year of symptom onset in SLDSS. If onset date was not stated in SLDSS, case year for confirmed cases was determined by the following dates (in order of reporting): positive laboratory date (by either urinary antigen testing, culture, or 4-fold rise of antibody titer against Legionella pneumophila serogroup 1); date patient was hospitalized during treatment for Legionnaires’ disease; or date case was first reported to public health at any level.
cSupplemental Legionnaires’ Disease Surveillance System (SLDSS).
dComplete reporting jurisdictions for 2018: 42 complete reporting jurisdictions reported at least 90% of confirmed NNDSS cases to SLDSS in 2018: Alabama, Alaska, Arizona, Arkansas, California, Colorado, Connecticut, Delaware, District of Columbia, Florida, Georgia, Hawaii, Illinois, Indiana, Iowa, Kansas, Kentucky, Maine, Maryland, Michigan, Minnesota, Mississippi, Missouri, Nebraska, New Hampshire, New York (state), New York City, North Carolina, North Dakota, Ohio, Oregon, Pennsylvania, Rhode Island, South Carolina, Tennessee, Texas, Utah, Vermont, Virginia, Washington, Wisconsin, and Wyoming.
Complete reporting jurisdictions for 2019: 38 complete reporting jurisdictions reported at least 90% of confirmed NNDSS cases to SLDSS in 2019: Alabama, Alaska, Arizona, California, Colorado, Connecticut, Delaware, District of Columbia, Florida, Georgia, Hawaii, Idaho, Illinois, Indiana, Iowa, Kansas, Kentucky, Maine, Michigan, Minnesota, Missouri, Montana, Nebraska, Nevada, New Hampshire, New York (state), New York City, Ohio, Oregon, Pennsylvania, Rhode Island, Tennessee, Texas, Utah, Vermont, Virginia, Washington, and Wyoming.

Figure 8. Percent of reported confirmed cases of Legionnaires’ disease resulting in deatha by age group and yearb—SLDSS,c complete reporting jurisdictions,d 2018 and 2019.

Figure 8. Percent of reported confirmed cases of Legionnaires’ disease resulting in death by age group and year—SLDSS, complete reporting jurisdictions, 2018 and 2019

aBased on outcome at time of case reporting.
bBased on year of symptom onset in SLDSS. If onset date was not stated in SLDSS, case year for confirmed cases was determined by the following dates (in order of reporting): positive laboratory date (by either urinary antigen testing, culture, or 4-fold rise of antibody titer against Legionella pneumophila serogroup 1); date patient was hospitalized during treatment for Legionnaires’ disease; or date case was first reported to public health at any level.
cSupplemental Legionnaires’ Disease Surveillance System (SLDSS).
dComplete reporting jurisdictions for 2018: 42 complete reporting jurisdictions reported at least 90% of confirmed NNDSS cases to SLDSS in 2018: Alabama, Alaska, Arizona, Arkansas, California, Colorado, Connecticut, Delaware, District of Columbia, Florida, Georgia, Hawaii, Illinois, Indiana, Iowa, Kansas, Kentucky, Maine, Maryland, Michigan, Minnesota, Mississippi, Missouri, Nebraska, New Hampshire, New York (state), New York City, North Carolina, North Dakota, Ohio, Oregon, Pennsylvania, Rhode Island, South Carolina, Tennessee, Texas, Utah, Vermont, Virginia, Washington, Wisconsin, and Wyoming.
Complete reporting jurisdictions for 2019: 38 complete reporting jurisdictions reported at least 90% of confirmed NNDSS cases to SLDSS in 2019: Alabama, Alaska, Arizona, California, Colorado, Connecticut, Delaware, District of Columbia, Florida, Georgia, Hawaii, Idaho, Illinois, Indiana, Iowa, Kansas, Kentucky, Maine, Michigan, Minnesota, Missouri, Montana, Nebraska, Nevada, New Hampshire, New York (state), New York City, Ohio, Oregon, Pennsylvania, Rhode Island, Tennessee, Texas, Utah, Vermont, Virginia, Washington, and Wyoming.

Table 7. Number of reported confirmed cases of Legionnaires’ disease by diagnostic testing methoda and yearb—SLDSS,c United States, 2018 and 2019.

Table 7. Number of reported confirmed cases of Legionnaires’ disease by diagnostic testing method and year—SLDSS, United States, 2016 and 2017.
2018 2019 Total
N % N % N %
Diagnostic testing method
Urinary antigen test 8,764 97.4 6,973 96.3 15,737 96.9
Serology 6 0.1 1 0.0 7 0.0
Culture 363 4.0 345 4.8 708 4.4
Culture site
Respiratory secretiond 285 78.5 252 73.0 537 75.8
Lung biopsy 7 1.9 10 2.9 17 2.4
Pleural fluid 7 1.9 1 0.3 8 1.1
Blood 7 1.9 4 1.2 11 1.6
Other 5 1.4 14 4.1 19 2.7
Not stated 52 14.3 64 18.6 116 16.4
Culture species
L. pneumophila 253 69.7 226 65.5 479 67.7
Serogroup 1 153 138 291
Serogroup 3 4 3 7
Serogroup 4 1 0 1
Serogroup 5 4 2 6
Serogroup 6 8 4 12
Serogroup 8 1 0 1
Serogroup 10 1 0 1
Serogroup 15 1 0 1
L. longbeachae 8 2.2 5 1.4 13 1.8
Serogroup 1 1 1 2
L. micdadei 4 1.1 5 1.4 9 1.3
L. bozemanii 3 0.8 5 1.4 8 1.1
Serogroup 2 0 1 1
L. anisa 2 0.6 1 0.3 3 0.4
L. feeleii 2 0.6 1 0.3 3 0.4
L. dumoffii 1 0.3 1 0.3 2 0.3
L. sainthelensi 1 0.3 1 0.3 2 0.3
L. gormanii 0 0.0 1 0.3 1 0.1
L. rubrilucens 0 0.0 1 0.3 1 0.1
Not stated 90 24.8 102 29.6 192 27.1
aMore than one type of test might apply. Laboratory criteria for diagnosis include the following for confirmed cases:
Urinary antigen test: detection of Legionella pneumophila serogroup 1 antigen in urine using validated reagents.
Culture: isolation of any Legionella organism from respiratory secretions, lung tissue, pleural fluid, or other normally sterile site.
Serology: 4-fold or greater rise in specific serum antibody titer to L. pneumophila serogroup 1 using validated reagents detected 3–6 weeks apart.
bBased on year of symptom onset in SLDSS. If onset date was not stated in SLDSS, case year for confirmed cases was determined by the following dates (in order of reporting): positive laboratory date (by either urinary antigen testing, culture, or 4-fold rise of antibody titer against Legionella pneumophila serogroup 1); date patient was hospitalized during treatment for Legionnaires’ disease; or date case was first reported to public health at any level.
cSupplemental Legionnaires’ Disease Surveillance System (SLDSS).
dRespiratory secretions include sputum, bronchial wash, bronchoalveolar lavage.
Print
Content Source:
National Center for Immunization and Respiratory Diseases; National Center for Environmental Health