Surveillance Report 2016-2017

What to know

This page features accessible versions of tables in the 2016-2017 Legionnaires’ Disease Surveillance Summary Report.

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Figure 1. Crude incidencea rates of reported confirmed cases of Legionnaires’ diseaseb by yearc—NNDSS,d,e United States, 2000–2017.

Figure 1: Crude incidence rates of reported confirmed cases of Legionnaires’ disease by year—NNDSS, United States, 2000–2017.

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 due to Legionnaires’ disease).

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, 2016 and 2017.

Figure 2: Number of reported confirmed cases of Legionnaires’ disease by month and year—NNDSS, United States, 2016 and 2017.

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 due to Legionnaires’ disease).

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 [2 pages]).

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, 2016.e,f

Figure 3a: Crude incidence rates of reported confirmed cases of Legionnaires’ disease by jurisdiction of residence—NNDSS, United States, 2016.

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 due to Legionnaires’ disease).

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, 2017.e,f

Figure 3b: Crude incidence rates of reported confirmed cases of Legionnaires’ disease by  jurisdiction of residence—NNDSS, United States, 2017.

 

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 due to Legionnaires’ disease).

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, 2016 and 2017.

Table 1. Number of reported confirmed cases of Legionnaires’ disease by jurisdiction of residence and year—NNDSS, United States, 2016 and 2017.
2016
(Total=6,141)
2017
(Total=7,458)
Jurisdiction N % N %
ALABAMA 63 1.0 66 0.9
ALASKA 1 0.0 6 0.1
ARIZONA 76 1.2 74 1.0
ARKANSAS 48 0.8 56 0.8
CALIFORNIA 586 9.5 535 7.2
COLORADO 57 0.9 82 1.1
CONNECTICUT 78 1.3 120 1.6
DELAWARE 26 0.4 34 0.5
D.C. 12 0.2 46 0.6
FLORIDA 328 5.3 435 5.8
GEORGIA 118 1.9 159 2.1
HAWAII 7 0.1 8 0.1
IDAHO 10 0.2 12 0.2
ILLINOIS 318 5.2 332 4.5
INDIANA 172 2.8 198 2.7
IOWA 33 0.5 35 0.5
KANSAS 32 0.5 34 0.5
KENTUCKY 102 1.7 116 1.6
LOUISIANA 33 0.5 49 0.7
MAINE 16 0.3 16 0.2
MARYLAND 142 2.3 187 2.5
MASSACHUSETTS 141 2.3 201 2.7
MICHIGAN 294 4.8 347 4.7
MINNESOTA 115 1.9 98 1.3
MISSISSIPPI 32 0.5 52 0.7
MISSOURI 159 2.6 138 1.9
MONTANA 10 0.2 17 0.2
NEBRASKA 17 0.3 29 0.4
NEVADA 26 0.4 14 0.2
NEW HAMPSHIRE 28 0.5 63 0.8
NEW JERSEY 199 3.2 249 3.3
NEW MEXICO 22 0.4 13 0.2
NEW YORK CITY 268 4.4 435 5.8
NEW YORK 463 7.5 587 7.9
NORTH CAROLINA 232 3.8 212 2.8
NORTH DAKOTA 5 0.1 7 0.1
OHIO 503 8.2 601 8.1
OKLAHOMA 60 1.0 65 0.9
OREGON 36 0.6 37 0.5
PENNSYLVANIA 371 6.0 500 6.7
RHODE ISLAND 37 0.6 50 0.7
SOUTH CAROLINA 62 1.0 55 0.7
SOUTH DAKOTA 9 0.2 15 0.2
TENNESSEE 126 2.1 207 2.8
TEXAS 270 4.4 327 4.4
UTAH 30 0.5 32 0.4
VERMONT 10 0.2 22 0.3
VIRGINIA 144 2.3 197 2.6
WASHINGTON 67 1.1 56 0.8
WEST VIRGINIA 30 0.5 49 0.7
WISCONSIN 114 1.9 176 2.4
WYOMING 3 0.1 7 0.1
Total 6,141 100.0 7,458 100.0

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 figure (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, 2016 and 2017.

Table 2. Number, percent, and crude incidence rates of reported confirmed cases of Legionnaires’ disease by demographic characteristics and year—NNDSS, United States, 2016 and 2017.
2016 2017
Characteristic N % Ratea N % Ratea
Age
0–9 8 0.1 0.02 5 0.1 0.01
10–19 19 0.3 0.05 11 0.2 0.03
20–29 112 1.8 0.25 154 2.1 0.34
30–39 330 5.4 0.78 421 5.6 0.97
40–49 675 11.0 1.66 789 10.6 1.94
50–59 1,433 23.3 3.27 1,683 22.6 3.88
60–69 1,584 25.8 4.36 1,919 25.7 5.21
70–79 1057 17.2 5.24 1,418 19.0 6.57
80–84 388 6.3 6.61 459 6.2 7.69
85+ 534 8.7 8.37 598 8.0 9.24
Not stated 1 0.0 N/A 1 0.0 N/A
Sex
Female 2,458 40.0 1.50 2,865 38.4 1.73
Male 3,679 59.9 2.31 4,589 61.5 2.86
Not stated 4 0.1 N/A 4 0.1 N/A
Race
American Indian/Alaska Native 26 0.4 0.56 28 0.4 0.60
Asian/Pacific Islander 99 1.6 0.48 103 1.4 0.49
African American/Black 1068 17.4 2.36 1,579 21.2 3.44
White 3,891 63.4 1.54 4,706 63.1 1.85
Othere 242 3.9 N/A 215 2.9 N/A
Not stated 815 13.3 N/A 827 11.1 N/A
Ethnicity
Hispanic 397 6.5 0.69 435 5.8 0.74
Non-Hispanic 4,506 73.4 1.70 5,500 73.8 2.06
Not stated 1,238 20.2 N/A 1,523 20.4 N/A
Total 6,141 100.0 1.90 7,458 100.0 2.29

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).

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, 2016 and 2017.

Figure 4a: Percent of reported confirmed cases of Legionnaires’ disease by age group and year—NNDSS and SLDSS, United States, 2016 and 2017.

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 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.

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, 2016 and 2017.

Figure 4b: Percent of reported confirmed cases of Legionnaires’ disease by sex and year—NNDSS and SLDSS, United States, 2016 and 2017.

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 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.

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, 2016 and 2017.

Figure 4c: Percent of reported confirmed cases of Legionnaires’ disease by race and year—NNDSS and SLDSS, United States, 2016 and 2017.

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 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.

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, 2016 and 2017.

Figure 4d: Percent of reported confirmed cases of Legionnaires’ disease by ethnicity and year—NNDSS and SLDSS, United States, 2016 and 2017.

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 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.

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, 2016.d

Figure 5a: Reported confirmed cases of legionellosis by syndrome and completeness of jurisdictional reporting—SLDSS, United States, 2016.

aLegionellosis includes Legionnaires’ disease, Pontiac fever, and extrapulmonary legionellosis.

b35 complete reporting jurisdictions reported at least 90% of confirmed NNDSS cases to SLDSS in 2016: Alabama, Alaska, Arkansas, Arizona, Colorado, Connecticut, Delaware, Florida, Georgia, Hawaii, Iowa, Illinois, Kansas, Kentucky, Maine, Michigan, Minnesota, Mississippi, Missouri, Montana, New Hampshire, New Jersey, New York City, New York (state), Ohio, Pennsylvania, Rhode Island, South Carolina, Utah, Vermont, Virginia, Washington, West Virginia, 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 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.

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, 2017.d

Figure 5b: Reported confirmed cases of legionellosis by syndrome and completeness of jurisdictional reporting—SLDSS, United States, 2017.

aLegionellosis includes Legionnaires’ disease, Pontiac fever, and extrapulmonary legionellosis.

b39 complete reporting jurisdictions reported at least 90% of confirmed NNDSS cases to SLDSS in 2017: Alabama, Alaska, Arkansas, Colorado, Connecticut, Florida, Georgia, Iowa, Illinois, Kansas, Kentucky, Maryland, Maine, Michigan, Minnesota, Mississippi, Missouri, Montana, Nebraska, New Hampshire, New Jersey, New York City, New York (state), North Carolina, North Dakota, Ohio, Oklahoma, Oregon, Pennsylvania, Rhode Island, South Carolina, Tennessee, Texas, Utah, Vermont, Washington, West Virginia, 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 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.

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 2016.d

Figure 6a. Number of reported confirmed cases and deaths of Legionnaires’ disease by exposure category—SLDSS, complete reporting jurisdictions, 2016.
Cases
(Total = 4,150)
Deaths
(Total= 276)
Exposure category N % N CFRe
Any healthcare 835 20.1 87 10.4
Definite healthcare 178 4.3 30 16.9
Possible healthcare 657 15.8 57 8.7
Any travel 616 14.8 30 4.9
Any assisted or senior living 152 3.7 14 9.2
None of these 2,693 64.9 160 5.9
Figure 6a: Number of reported confirmed cases and deaths of Legionnaires’ disease by exposure category—SLDSS, complete reporting jurisdictions, 2016.

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: 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 2016: 35 complete reporting jurisdictions reported at least 90% of confirmed NNDSS cases to SLDSS: Alabama, Alaska, Arkansas, Arizona, Colorado, Connecticut, Delaware, Florida, Georgia, Hawaii, Iowa, Illinois, Kansas, Kentucky, Maine, Michigan, Minnesota, Mississippi, Missouri, Montana, New Hampshire, New Jersey, New York City, New York (state), Ohio, Pennsylvania, Rhode Island, South Carolina, Utah, Vermont, Virginia, Washington, West Virginia, 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 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.

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 2017.d

Figure 6b. Number of reported confirmed cases and deaths of Legionnaires’ disease by exposure category—SLDSS, complete reporting jurisdictions, 2017.
Cases
(Total = 5,898)
Deaths
(Total= 438)
Exposure category N % N CFRe
Any healthcare 1255 21.3 142 11.3
Definite healthcare 232 3.9 47 20.3
Possible healthcare 1023 17.3 95 9.3
Any travel 931 15.8 30 3.2
Any assisted or senior living 211 3.6 22 10.4
None of these 3,733 63.3 260 7.0
Figure 6b: Number of reported confirmed cases and deaths of Legionnaires’ disease by exposure category—SLDSS, complete reporting jurisdictions, 2017.

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: 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 2017: 39 complete reporting jurisdictions reported at least 90% of confirmed NNDSS cases to SLDSS in 2017: Alabama, Alaska, Arkansas, Colorado, Connecticut, Florida, Georgia, Iowa, Illinois, Kansas, Kentucky, Maryland, Maine, Michigan, Minnesota, Mississippi, Missouri, Montana, Nebraska, New Hampshire, New Jersey, New York City, New York (state), North Carolina, North Dakota, Ohio, Oklahoma, Oregon, Pennsylvania, Rhode Island, South Carolina, Tennessee, Texas, Utah, Vermont, Washington, West Virginia, 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 (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.

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 2016 and 2017.

Table 3. Number of reported confirmed cases of Legionnaires’ disease by exposure category and year—SLDSS, complete reporting jurisdictions, 2014 and 2015.
2016
(Total = 4,150)
2017
(Total = 5,898)
Exposure category N % N %
Healthcare 835 20.1 1255 21.3
Healthcare facility type
Hospital 325 38.9 443 35.3
Long-term care facility 197 23.6 282 22.5
Clinic 196 23.5 335 26.7
Multiple 89 10.7 125 10.0
Other 1 0.1 0 0.0
Not stated 27 3.2 70 5.6
Healthcare exposure type
Inpatient 317 38.0 430 34.3
Outpatient 292 35.0 460 36.7
Visitor 74 8.9 143 11.4
Employee 70 8.4 89 7.1
Multiple 50 6.0 61 4.9
Not stated 32 3.8 72 5.7
Travel 616 14.8 931 15.8
Any public accommodation 417 67.7 585 62.8
Hotel/motel/resort 412 576
Cruise ship 11 18
All private accommodations 181 29.4 239 25.7
Unknown travel accommodation type 18 2.9 107 11.5
Assisted or senior living 152 3.7 211 3.6
Assisted or senior living facility type
Assisted living facility 90 59.2 121 57.3
Senior living facility 48 31.6 64 30.3
Both 1 0.7 1 0.5
Not stated 13 8.6 25 11.8
Assisted or senior living exposure type
Resident 99 65.1 137 64.9
Visitor 25 16.4 41 19.4
Employee 11 7.2 9 4.3
Not stated 17 11.2 24 11.4
None of these 2,693 64.9 3,733 63.3

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 2016: 35 complete reporting jurisdictions reported at least 90% of confirmed NNDSS cases to SLDSS: Alabama, Alaska, Arkansas, Arizona, Colorado, Connecticut, Delaware, Florida, Georgia, Hawaii, Iowa, Illinois, Kansas, Kentucky, Maine, Michigan, Minnesota, Mississippi, Missouri, Montana, New Hampshire, New Jersey, New York City, New York (state), Ohio, Pennsylvania, Rhode Island, South Carolina, Utah, Vermont, Virginia, Washington, West Virginia, Wisconsin, and Wyoming.
Complete reporting jurisdictions for 2017: 39 complete reporting jurisdictions reported at least 90% of confirmed NNDSS cases to SLDSS in 2017: Alabama, Alaska, Arkansas, Colorado, Connecticut, Florida, Georgia, Iowa, Illinois, Kansas, Kentucky, Maryland, Maine, Michigan, Minnesota, Mississippi, Missouri, Montana, Nebraska, New Hampshire, New Jersey, New York City, New York (state), North Carolina, North Dakota, Ohio, Oklahoma, Oregon, Pennsylvania, Rhode Island, South Carolina, Tennessee, Texas, Utah, Vermont, Washington, West Virginia, Wisconsin, and Wyoming.

Table 4a. Number of reported confirmed cases of Legionnaires’ disease by demographic characteristics and exposure categorya—SLDSS,b complete reporting jurisdictions,c 2016.d

Table 4a. Number of reported confirmed cases of Legionnaires’ disease by demographic characteristics and exposure category—SLDSS, complete reporting jurisdictions, 2016.
Exposure category
Healthcare
(Total = 835)
Travel
(Total = 616)
Assisted or senior living
(Total = 152)
None of these
(Total = 2,693)
Characteristic N % N % N % N %
Median Age (years) 65 61 78 61
Age
0–9 3 0.4 1 0.2 0 0.0 3 0.1
10–19 3 0.4 2 0.3 0 0.0 5 0.2
20–29 12 1.4 13 2.1 0 0.0 59 2.2
30–39 40 4.8 35 5.7 6 3.9 164 6.1
40–49 60 7.2 80 13.0 7 4.6 303 11.3
50–59 167 20.0 144 23.4 15 9.9 673 25.0
60–69 212 25.4 203 33.0 28 18.4 715 26.6
70–79 160 19.2 87 14.1 25 16.4 441 16.4
80–84 63 7.5 28 4.5 24 15.8 153 5.7
85+ 114 13.7 21 3.4 47 30.9 175 6.5
Not stated 1 0.1 2 0.3 0 0.0 2 0.1
Sex
Female 413 49.5 242 39.3 88 57.9 964 35.8
Male 418 50.1 370 60.1 64 42.1 1,712 63.6
Not stated 4 0.5 4 0.6 0 0.0 17 0.6
Race
American Indian/Alaska Native 4 0.5 5 0.8 0 0.0 7 0.3
Asian 14 1.7 8 1.3 3 2.0 27 1.0
Black or African American 142 17.0 86 14.0 23 15.1 558 20.7
Native Hawaiian/Other Pacific Islander 0 0.0 0 0.0 0 0.0 6 0.2
White 519 62.2 397 64.4 87 57.2 1,590 59.0
Multiple 1 0.1 0 0.0 0 0.0 6 0.2
Not stated 155 18.6 120 19.5 39 25.7 499 18.5
Ethnicity
Hispanic 31 3.7 22 3.6 5 3.3 132 4.9
Non-Hispanic 651 78.0 460 74.7 115 75.7 2,039 75.7
Not stated 153 18.3 134 21.8 32 21.1 522 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 2016: 35 complete reporting jurisdictions reported at least 90% of confirmed NNDSS cases to SLDSS in 2016: Alabama, Alaska, Arkansas, Arizona, Colorado, Connecticut, Delaware, Florida, Georgia, Hawaii, Iowa, Illinois, Kansas, Kentucky, Maine, Michigan, Minnesota, Mississippi, Missouri, Montana, New Hampshire, New Jersey, New York City, New York (state), Ohio, Pennsylvania, Rhode Island, South Carolina, Utah, Vermont, Virginia, Washington, West Virginia, 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 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.

Table 4b. Number of reported confirmed cases of Legionnaires’ disease by demographic characteristics and exposure categorya—SLDSS,b complete reporting jurisdictions,c 2017.d

Table 4b. Number of reported confirmed cases of Legionnaires’ disease by demographic characteristics and exposure category—SLDSS, complete reporting jurisdictions, 2017.
Exposure category
Healthcare
(Total = 1,255)
Travel
(Total = 931)
Assisted or senior living
(Total = 211)
None of these
(Total = 3,733)
Characteristic N % N % N % N %
Median Age (years) 66 61 74 61
Age
0–9 1 0.1 0 0.0 0 0.0 1 0.0
10–19 3 0.2 0 0.0 0 0.0 5 0.1
20–29 21 1.7 21 2.3 6 2.8 85 2.3
30–39 48 3.8 71 7.6 7 3.3 228 6.1
40–49 110 8.8 110 11.8 8 3.8 442 11.8
50–59 250 19.9 211 22.7 29 13.7 922 24.7
60–69 295 23.5 285 30.6 39 18.5 941 25.2
70–79 279 22.2 152 16.3 40 19.0 665 17.8
80–84 96 7.6 49 5.3 24 11.4 206 5.5
85+ 151 12.0 29 3.1 58 27.5 234 6.3
Not stated 1 0.1 3 0.3 0 0.0 4 0.1
Sex
Female 563 44.9 360 38.7 98 46.4 1301 34.9
Male 682 54.3 564 60.6 111 52.6 2,409 64.5
Not stated 10 0.8 7 0.8 2 0.9 23 0.6
Race
American Indian/Alaska Native 5 0.4 4 0.4 1 0.5 8 0.2
Asian 12 1.0 6 0.6 1 0.5 33 0.9
Black or African American 251 20.0 157 16.9 41 19.4 860 23.0
Native Hawaiian/Other Pacific Islander 0 0.0 0 0.0 0 0.0 2 0.1
White 846 67.4 636 68.3 149 70.6 2,296 61.5
Multiple 3 0.2 1 0.1 0 0.0 10 0.3
Not stated 138 11.0 127 13.6 19 9.0 524 14.0
Ethnicity
Hispanic 54 4.3 41 4.4 4 1.9 207 5.5
Non-Hispanic 968 77.1 692 74.3 166 78.7 2,821 75.6
Not stated 233 18.6 198 21.3 41 19.4 705 18.9

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 2017: 39 complete reporting jurisdictions reported at least 90% of confirmed NNDSS cases to SLDSS in 2017: Alabama, Alaska, Arkansas, Colorado, Connecticut, Florida, Georgia, Iowa, Illinois, Kansas, Kentucky, Maryland, Maine, Michigan, Minnesota, Mississippi, Missouri, Montana, Nebraska, New Hampshire, New Jersey, New York City, New York (state), North Carolina, North Dakota, Ohio, Oklahoma, Oregon, Pennsylvania, Rhode Island, South Carolina, Tennessee, Texas, Utah, Vermont, Washington, West Virginia, 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 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.

Table 5a. Number of reported confirmed cases of healthcare-associateda Legionnaires’ disease by healthcare facility type and healthcare exposure certaintyb—SLDSS,c complete reporting jurisdictionsd, 2016.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, 2016.
Healthcare exposure certainty
Definite Possible Total
Facility type N % N % N %
Hospital 31 17.4 294 44.7 325 38.9
Long-term care facility 110 61.8 87 13.2 197 23.6
Clinic 0 0.0 196 29.8 196 23.5
Multiplef 31 17.4 58 8.8 89 10.7
Otherg 0 0.0 1 0.2 1 0.1
Not stated 6 3.4 21 3.2 27 3.2
Total 178 100 657 100 835 100

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 2016: 35 complete reporting jurisdictions reported at least 90% of confirmed NNDSS cases to SLDSS in 2016: Alabama, Alaska, Arkansas, Arizona, Colorado, Connecticut, Delaware, Florida, Georgia, Hawaii, Iowa, Illinois, Kansas, Kentucky, Maine, Michigan, Minnesota, Mississippi, Missouri, Montana, New Hampshire, New Jersey, New York City, New York (state), Ohio, Pennsylvania, Rhode Island, South Carolina, Utah, Vermont, Virginia, Washington, West Virginia, 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 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.

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 2017.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, 2017.
Healthcare exposure certainty
Definite Possible Total
Facility type N % N % N %
Hospital 43 18.5 400 39.1 443 35.3
Long-term care facility 137 59.1 145 14.2 282 22.5
Clinic 0 0.0 335 32.7 335 26.7
Multiplef 43 18.5 82 8.0 125 10.0
Otherg 0 0.0 0 0.0 0 0.0
Not stated 9 3.9 61 6.0 70 5.6
Total 232 100 1023 100 1255 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 2017: 39 complete reporting jurisdictions reported at least 90% of confirmed NNDSS cases to SLDSS in 2017: Alabama, Alaska, Arkansas, Colorado, Connecticut, Florida, Georgia, Iowa, Illinois, Kansas, Kentucky, Maryland, Maine, Michigan, Minnesota, Mississippi, Missouri, Montana, Nebraska, New Hampshire, New Jersey, New York City, New York (state), North Carolina, North Dakota, Ohio, Oklahoma, Oregon, Pennsylvania, Rhode Island, South Carolina, Tennessee, Texas, Utah, Vermont, Washington, West Virginia, 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 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.

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 2016.f

Table 6a. Number of reported confirmed cases of Legionnaires’ disease by hospitalization, outcome, and exposure category—SLDSS, complete reporting jurisdictions, 2016.
Exposure category
Healthcare
(Total = 835)
Travel
(Total = 616)
Assisted or senior living
(Total = 152)
None of these
(Total = 2,693)
N % N % N % N %
Hospitalization
Yes 777 93.1 579 94.0 139 91.4 2,588 96.1
No 52 6.2 27 4.4 10 6.6 76 2.8
Not stated 6 0.7 10 1.6 3 2.0 29 1.1
Outcome
Death 87 10.4 30 4.9 14 9.2 160 5.9
Still ill 105 12.6 56 9.1 17 11.2 228 8.5
Survived 608 72.8 476 77.3 99 65.1 1,868 69.4
Not stated 35 4.2 54 8.8 22 14.5 437 16.2

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 2016: 35 complete reporting jurisdictions reported at least 90% of confirmed NNDSS cases to SLDSS in 2016: Alabama, Alaska, Arkansas, Arizona, Colorado, Connecticut, Delaware, Florida, Georgia, Hawaii, Iowa, Illinois, Kansas, Kentucky, Maine, Michigan, Minnesota, Mississippi, Missouri, Montana, New Hampshire, New Jersey, New York City, New York (state), Ohio, Pennsylvania, Rhode Island, South Carolina, Utah, Vermont, Virginia, Washington, West Virginia, 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 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.

Table 6b. Number of reported confirmed cases of Legionnaires’ disease by hospitalization,a outcome,b and exposure categoryc—SLDSS,d complete reporting jurisdictions,e 2017.f

Table 6b. Number of reported confirmed cases of Legionnaires’ disease by hospitalization, outcome, and exposure category—SLDSS, complete reporting jurisdictions, 2017.
Exposure category
Healthcare
(Total = 1,255)
Travel
(Total = 931)
Assisted or senior living
(Total = 211)
None of these
(Total = 3,733)
N % N % N % N %
Hospitalization
Yes 1193 95.1 886 95.2 201 95.3 3,613 96.8
No 55 4.4 18 1.9 9 4.3 79 2.1
Not stated 7 0.6 27 2.9 1 0.5 41 1.1
Outcome
Death 142 11.3 30 3.2 22 10.4 260 7.0
Still ill 133 10.6 95 10.2 15 7.1 310 8.3
Survived 860 68.5 701 75.3 152 72.0 2,653 71.1
Not stated 120 9.6 105 11.3 22 10.4 510 13.7

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 2017: 39 complete reporting jurisdictions reported at least 90% of confirmed NNDSS cases to SLDSS in 2017: Alabama, Alaska, Arkansas, Colorado, Connecticut, Florida, Georgia, Iowa, Illinois, Kansas, Kentucky, Maryland, Maine, Michigan, Minnesota, Mississippi, Missouri, Montana, Nebraska, New Hampshire, New Jersey, New York City, New York (state), North Carolina, North Dakota, Ohio, Oklahoma, Oregon, Pennsylvania, Rhode Island, South Carolina, Tennessee, Texas, Utah, Vermont, Washington, West Virginia, 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 urine 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.

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 2016 and 2017.

Figure 7: Percent of reported confirmed cases of Legionnaires’ disease that were treated in hospital by age group and year—SLDSS, complete reporting jurisdictions, 2016 and 2017.

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 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 for 2016: 35 complete reporting jurisdictions reported at least 90% of confirmed NNDSS cases to SLDSS in 2016: Alabama, Alaska, Arkansas, Arizona, Colorado, Connecticut, Delaware, Florida, Georgia, Hawaii, Iowa, Illinois, Kansas, Kentucky, Maine, Michigan, Minnesota, Mississippi, Missouri, Montana, New Hampshire, New Jersey, New York City, New York (state), Ohio, Pennsylvania, Rhode Island, South Carolina, Utah, Vermont, Virginia, Washington, West Virginia, Wisconsin, and Wyoming.

Complete reporting jurisdictions for 2017: 39 complete reporting jurisdictions reported at least 90% of confirmed NNDSS cases to SLDSS in 2017: Alabama, Alaska, Arkansas, Colorado, Connecticut, Florida, Georgia, Iowa, Illinois, Kansas, Kentucky, Maryland, Maine, Michigan, Minnesota, Mississippi, Missouri, Montana, Nebraska, New Hampshire, New Jersey, New York City, New York (state), North Carolina, North Dakota, Ohio, Oklahoma, Oregon, Pennsylvania, Rhode Island, South Carolina, Tennessee, Texas, Utah, Vermont, Washington, West Virginia, Wisconsin, 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 2016 and 2017.

Figure 8: Percent of reported confirmed cases of Legionnaires’ disease resulting in death by age group and year—SLDSS, complete reporting jurisdictions, 2016 and 2017.

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 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 for 2016: 35 complete reporting jurisdictions reported at least 90% of confirmed NNDSS cases to SLDSS in 2016: Alabama, Alaska, Arkansas, Arizona, Colorado, Connecticut, Delaware, Florida, Georgia, Hawaii, Iowa, Illinois, Kansas, Kentucky, Maine, Michigan, Minnesota, Mississippi, Missouri, Montana, New Hampshire, New Jersey, New York City, New York (state), Ohio, Pennsylvania, Rhode Island, South Carolina, Utah, Vermont, Virginia, Washington, West Virginia, Wisconsin, and Wyoming.

Complete reporting jurisdictions for 2017: 39 complete reporting jurisdictions reported at least 90% of confirmed NNDSS cases to SLDSS in 2017: Alabama, Alaska, Arkansas, Colorado, Connecticut, Florida, Georgia, Iowa, Illinois, Kansas, Kentucky, Maryland, Maine, Michigan, Minnesota, Mississippi, Missouri, Montana, Nebraska, New Hampshire, New Jersey, New York City, New York (state), North Carolina, North Dakota, Ohio, Oklahoma, Oregon, Pennsylvania, Rhode Island, South Carolina, Tennessee, Texas, Utah, Vermont, Washington, West Virginia, Wisconsin, and Wyoming.

Table 7. Number of reported confirmed cases of Legionnaires’ disease by diagnostic testing methoda and yearb—SLDSS,c United States, 2016 and 2017.

Table 7. Number of reported confirmed cases of Legionnaires’ disease by diagnostic testing method and year—SLDSS, United States, 2016 and 2017.
2016 2017 Total
N % N % N %
Diagnostic testing method
Urinary antigen test 4,674 97.8 6,103 98.1 10,777 98.0
Serology 6 0.1 3 0.0 9 0.1
Culture 173 3.6 209 3.4 382 3.5
Culture site
Respiratory secretiond 149 86.1 180 86.1 329 86.1
Blood 5 2.9 6 2.9 11 2.9
Lung biopsy 5 2.9 5 2.4 10 2.6
Pleural fluid 3 1.7 1 0.5 4 1.0
Other 1 0.6 1 0.5 2 0.5
Not stated 10 5.8 16 7.7 26 6.8
Culture species
L. pneumophila 115 66.5 115 55.0 230 60.2
Serogroup 1 51 60 111
Serogroup 2 0 1 1
Serogroup 4 2 0 2
Serogroup 5 1 3 4
Serogroup 6 1 1 2
Serogroup 9 6 0 6
Serogroup 10 0 1 1
Serogroup 12 0 2 2
L. micdadei 4 2.3 3 1.4 7 1.8
L. bozemanii 2 1.2 0 0.0 2 0.5
L. gormanii 2 1.2 0 0.0 2 0.5
L. donaldsonii 0 0.0 1 0.5 1 0.3
L. feeleii 0 0.0 1 0.5 1 0.3
L. longbeachae 1 0.6 0 0.0 1 0.3
L. parisiensis 0 0.0 1 0.5 1 0.3
Other or not stated 49 28.3 88 42.1 137 35.9

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: fourfold 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 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).

dRespiratory secretions include sputum, bronchial wash, bronchoalveolar lavage.