Surveillance Report 2014-2015

On This Page

Table 1. Number of reported confirmed cases of Legionnaires’ diseasea by jurisdiction of residenceb and yearc—NNDSS,d United States, 2014 and 2015.

Table 1. Number of reported confirmed cases of Legionnaires’ disease by jurisdiction of residence and year—NNDSS, United States, 2014 and 2015.
2014
(Total= 5,166)
2015
(Total= 6,079)
Percent Change
Jurisdiction N % N % %
ALABAMA 63 1.2 59 1.0 -6.3
ALASKA 2 0.0 0 0.0 -100.0
ARIZONA 59 1.1 93 1.5 57.6
ARKANSAS 38 0.7 37 0.6 -2.6
CALIFORNIA 351 6.8 453 7.5 29.1
COLORADO 65 1.3 74 1.2 13.8
CONNECTICUT 60 1.2 57 0.9 -5.0
DELAWARE 20 0.4 24 0.4 20.0
D.C. 13 0.3 13 0.2 0.0
FLORIDA 280 5.4 306 5.0 9.3
GEORGIA 93 1.8 121 2.0 30.1
HAWAII 7 0.1 6 0.1 -14.3
IDAHO 17 0.3 13 0.2 -23.5
ILLINOIS 249 4.8 315 5.2 26.5
INDIANA 129 2.5 177 2.9 37.2
IOWA 33 0.6 36 0.6 9.1
KANSAS 19 0.4 31 0.5 63.2
KENTUCKY 95 1.8 87 1.4 -8.4
LOUISIANA 64 1.2 42 0.7 -34.4
MAINE 19 0.4 16 0.3 -15.8
MARYLAND 144 2.8 153 2.5 6.3
MASSACHUSETTS 144 2.8 162 2.7 12.5
MICHIGAN 229 4.4 251 4.1 9.6
MINNESOTA 59 1.1 51 0.8 -13.6
MISSISSIPPI 33 0.6 38 0.6 15.2
MISSOURI 106 2.1 148 2.4 39.6
MONTANA 4 0.1 8 0.1 100.0
NEBRASKA 23 0.5 18 0.3 -21.7
NEVADA 25 0.5 25 0.4 0.0
NEW HAMPSHIRE 12 0.2 32 0.5 166.7
NEW JERSEY 199 3.9 214 3.5 7.5
NEW MEXICO 8 0.2 17 0.3 112.5
NEW YORK CITY 228 4.4 437 7.2 91.7
NEW YORK STATE 422 8.2 433 7.1 2.6
NORTH CAROLINA 187 3.6 177 2.9 -5.3
NORTH DAKOTA 4 0.1 5 0.1 25.0
OHIO 406 7.9 572 9.4 40.9
OKLAHOMA 36 0.7 48 0.8 33.3
OREGON 33 0.6 47 0.8 42.4
PENNSYLVANIA 324 6.3 380 6.3 17.3
RHODE ISLAND 28 0.5 21 0.3 -25.0
SOUTH CAROLINA 45 0.9 59 1.0 31.1
SOUTH DAKOTA 10 0.2 10 0.2 0.0
TENNESSEE 161 3.1 119 2.0 -26.1
TEXAS 256 5.0 292 4.8 14.1
UTAH 28 0.5 31 0.5 10.7
VERMONT 7 0.1 18 0.3 157.1
VIRGINIA 129 2.5 139 2.3 7.8
WASHINGTON 55 1.1 56 0.9 1.8
WEST VIRGINIA 48 0.9 35 0.6 -27.1
WISCONSIN 95 1.8 119 2.0 25.3
WYOMING 2 0.0 4 0.1 100.0
Total 5,166 100 6,079 100 17.7

aCases of disease due to Legionella are reported to NNDSS as legionellosis, which includes Legionnaires’ disease, Pontiac fever, and disease due to Legionella infection at extrapulmonary sites, but is referred to as Legionnaires’ disease in this figure (almost all legionellosis cases reported in the United States are due to Legionnaires’ disease).
bJurisdiction of the patient’s “usual residence” at the time of disease onset.
cBased on year 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, 2014 and 2015.

Table 2. Number, percent, and crude incidencea rates of reported confirmed cases of Legionnaires’ disease by demographic characteristics and year—NNDSS, United States, 2014 and 2015.
2014 2015
Characteristic N % Ratea N % Ratea
Age
0–9 1 0.0 0.00 9 0.1 0.02
10–19 10 0.2 0.02 19 0.3 0.05
20–29 111 2.1 0.25 131 2.2 0.29
30–39 277 5.4 0.67 329 5.4 0.78
40–49 563 10.9 1.36 695 11.4 1.69
50–59 1,264 24.5 2.87 1,486 24.4 3.37
60–69 1,204 23.3 3.55 1,482 24.4 4.22
70–79 933 18.1 4.91 1,037 17.1 5.29
80–84 350 6.8 6.08 376 6.2 6.48
85+ 451 8.7 7.32 513 8.4 8.16
Not stated 2 0.0 2 0.0
Sex
Female 2,112 40.9 1.30 2,328 38.3 1.43
Male 3,050 59.0 1.94 3,748 61.7 2.37
Not stated 4 0.1 3 0.0
Race
American Indian/Alaska Native 21 0.4 0.46 18 0.3 0.39
Asian/Pacific Islander 69 1.3 0.36 86 1.4 0.43
African American/Black 901 17.4 2.03 1,111 18.3 2.48
White 3,155 61.1 1.26 3,761 61.9 1.49
Othere 122 2.4 150 2.5
Not stated 898 17.4 953 15.7
Ethnicityf
Hispanic 280 5.4 408 6.7
Non-Hispanic 3,577 69.2 4,356 71.7
Not stated 1,309 25.3 1,315 21.6
Total 5,166 100  1.62 6,079 100  1.89

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 disease due to Legionella infection at extrapulmonary sites, but is referred to as Legionnaires’ disease in this figure (almost all legionellosis cases reported in the United States are due to Legionnaires’ disease).
cBased on year case was reported to CDC.
dNational Notifiable Diseases Surveillance System (NNDSS).
eOther race includes individuals that did not identify with races listed.
fDue to significant proportion of missing ethnicity data reported, incidence rates by ethnicity are not presented.

Figure 6a. Number of reported confirmed cases and deaths of Legionnaires’ disease by exposure categorya—SLDSS,b complete reporting jurisdictions,c 2014.d

Figure 6a. Number of reported confirmed cases and deaths of Legionnaires’ disease by exposure category—SLDSS, complete reporting jurisdictions, 2014.
Cases
(Total = 3,263)
Deaths
(Total= 251)
Exposure category N % N CFRe
Any healthcare 656 20.1 78 11.9
Definite healthcare 150 4.6 34 22.7
Possible healthcare 506 15.5 44 8.7
Any travel 449 13.8 18 4.0
Any assisted or senior living 129 4.0 13 10.1
None of these 2,153 66.0 150 7.0
Figure 6a. Number of reported confirmed cases and deaths of Legionnaires’ disease by exposure category—SLDSS, complete reporting jurisdictions, 2014.

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 2014: 31 complete reporting jurisdictions reported at least 90% of confirmed NNDSS cases to SLDSS: Alabama, Alaska, Colorado, Connecticut, Florida, Georgia, Iowa, Kansas, Kentucky, Maine, Maryland, Michigan, Minnesota, Mississippi, Missouri, New Hampshire, New York City, New York State, North Dakota, Ohio, Pennsylvania, Rhode Island, South Carolina, Texas, 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 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.
fDiagram illustrates overlap of reported exposures. The numbers in each segment are mutually exclusive.

Figure 6b. Number of reported confirmed cases and deaths of Legionnaires’ disease by exposure categorya—SLDSS,b complete reporting jurisdictions,c 2015.d

Figure 6b. Number of reported confirmed cases and deaths of Legionnaires’ disease by exposure category—SLDSS, complete reporting jurisdictions, 2015.
Cases
(Total = 4,001)
Deaths
(Total= 282)
Exposure category N % N CFRe
Any healthcare 763 19.1 88 11.5
Definite healthcare 119 3.0 27 22.7
Possible healthcare 644 16.1 61 9.5
Any travel 565 14.1 21 3.7
Any assisted or senior living 116 2.9 11 9.5
None of these 2,683 67.1 173 6.4

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 2015: 31 complete reporting jurisdictions reported at least 90% of confirmed NNDSS cases to SLDSS: Alabama, Colorado, Connecticut, Florida, Georgia, Hawaii, Iowa, Kansas, Kentucky, Maine, Maryland, Michigan, Minnesota, Mississippi, Missouri, New Hampshire, New Mexico, New York City, New York State, North Dakota, Ohio, Pennsylvania, Rhode Island, South Carolina, Texas, 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 (by either urinary antigen testing, culture, or fourfold rise of antibody 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.
fDiagram illustrates overlap of reported exposures. The numbers in each segment are mutually exclusive.

Table 3. Number of reported confirmed cases of Legionnaires’ disease by exposure categorya and yearb—SLDSS,c complete reporting jurisdictions,d 2014 and 2015.

Table 3. Number of reported confirmed cases of Legionnaires’ disease by exposure category and year—SLDSS, complete reporting jurisdictions, 2014 and 2015.
2014
(Total = 3,263)
2015
(Total = 4,001)
Exposure category N % N %
Healthcare 656 20.1 763 19.1
Healthcare facility type
Hospital 282 43.0 328 43.0
Long-term care facility 172 26.2 170 22.3
Clinic 128 19.5 184 24.1
Multiple 53 8.1 59 7.7
Other 8 1.2 17 2.2
Not stated 13 2.0 5 0.7
Healthcare exposure type
Inpatient 293 44.7 287 37.6
Outpatient 204 31.1 289 37.9
Visitor 66 10.1 102 13.4
Employee 49 7.5 53 6.9
Multiple 25 3.8 23 3.0
Not stated 19 2.9 9 1.2
Travel 449 13.8 565 14.1
Any commercial accommodation 291 64.8 371 65.7
Hotel/motel/resort 287 365
Cruise ship 10 15
Non-commercial accommodation only 130 29.0 170 30.1
Unknown travel accommodation type 28 6.2 24 4.2
Assisted or senior living 129 4.0 116 2.9
Assisted or senior living facility type
Assisted living facility 82 63.6 69 59.5
Senior living facility 38 29.5 39 33.6
Not stated 9 7.0 8 6.9
Assisted or senior living exposure type
Resident 91 70.5 75 64.7
Visitor 19 14.7 23 19.8
Employee 9 7.0 7 6.0
Not stated 10 7.8 11 9.5
None of these 2,153 66.0 2,683 67.1

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 commercial accommodation occurs, the case is categorized as commercial travel. Non-commercial travel represents exposure to non-commercial accommodations only. If a patient has exposure to both non-commercial 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 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 2014: 31 complete reporting jurisdictions reported at least 90% of confirmed NNDSS cases to SLDSS: Alabama, Alaska, Colorado, Connecticut, Florida, Georgia, Iowa, Kansas, Kentucky, Maine, Maryland, Michigan, Minnesota, Mississippi, Missouri, New Hampshire, New York City, New York State, North Dakota, Ohio, Pennsylvania, Rhode Island, South Carolina, Texas, Utah, Vermont, Virginia, Washington, West Virginia, Wisconsin, and Wyoming.
Complete reporting jurisdictions in 2015: 31 complete reporting jurisdictions reported at least 90% of confirmed NNDSS cases to SLDSS: Alabama, Colorado, Connecticut, Florida, Georgia, Hawaii, Iowa, Kansas, Kentucky, Maine, Maryland, Michigan, Minnesota, Mississippi, Missouri, New Hampshire, New Mexico, New York City, New York State, North Dakota, Ohio, Pennsylvania, Rhode Island, South Carolina, Texas, Vermont, Virginia, 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 2014.d

Table 4a. Number of reported confirmed cases of Legionnaires’ disease by demographic characteristics and exposure category—SLDSS, complete reporting jurisdictions, 2014.
Exposure category
Healthcare
(Total = 656)
Travel
(Total = 449)
Assisted or senior living
(Total = 129)
None of these
(Total = 2,153)
Characteristic N % N % N % N %
Median Age (years) 67 60 78 61
Age
0–9 0 0.0 0 0.0 0 0.0 0 0.0
10–19 1 0.2 1 0.2 0 0.0 6 0.3
20–29 13 2.0 12 2.7 2 1.6 50 2.3
30–39 26 4.0 23 5.1 3 2.3 125 5.8
40–49 39 5.9 46 10.2 8 6.2 267 12.4
50–59 132 20.1 126 28.1 19 14.7 536 24.9
60–69 159 24.2 118 26.3 18 14.0 479 22.2
70–79 138 21.0 81 18.0 16 12.4 381 17.7
80–84 67 10.2 20 4.5 18 14.0 127 5.9
85+ 78 11.9 19 4.2 44 34.1 176 8.2
Not stated 3 0.5 3 0.7 1 0.8 6 0.3
Sex
Female 288 43.9 173 38.5 67 51.9 818 38.0
Male 360 54.9 272 60.6 59 45.7 1,319 61.3
Not stated 8 1.2 4 0.9 3 2.3 16 0.7
Race
American Indian/Alaska Native 5 0.8 1 0.2 1 0.8 8 0.4
Asian 1 0.2 3 0.7 0 0.0 4 0.2
Black or African American 119 18.1 68 15.1 17 13.2 445 20.7
Native Hawaiian/Other Pacific Islander 0 0.0 0 0.0 0 0.0 1 0.0
White 391 59.6 269 59.9 83 64.3 1,220 56.7
Multiple 1 0.2 0 0.0 1 0.8 3 0.1
Not stated 139 21.2 108 24.1 27 20.9 472 21.9
Ethnicity
Hispanic 21 3.2 18 4.0 0 0.0 111 5.2
Non-Hispanic 461 70.3 331 73.7 92 71.3 1,556 72.3
Not stated 174 26.5 100 22.3 37 28.7 486 22.6

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 2014: 31 complete reporting jurisdictions reported at least 90% of confirmed NNDSS cases to SLDSS: Alabama, Alaska, Colorado, Connecticut, Florida, Georgia, Iowa, Kansas, Kentucky, Maine, Maryland, Michigan, Minnesota, Mississippi, Missouri, New Hampshire, New York City, New York State, North Dakota, Ohio, Pennsylvania, Rhode Island, South Carolina, Texas, 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 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 2015.d

Table 4b. Number of reported confirmed cases of Legionnaires’ disease by demographic characteristics and exposure category—SLDSS, complete reporting jurisdictions, 2015.
Exposure category
Healthcare
(Total = 763)
Travel
(Total = 565)
Assisted or senior living
(Total = 116)
None of these
(Total = 2,683)
Characteristic N % N % N % N %
Median Age (years) 65 60 77 60
Age
0–9 0 0.0 0 0.0 0 0.0 2 0.1
10–19 1 0.1 1 0.2 0 0.0 9 0.3
20–29 19 2.5 12 2.1 1 0.9 53 2.0
30–39 18 2.4 32 5.7 0 0.0 171 6.4
40–49 55 7.2 79 14.0 1 0.9 350 13.0
50–59 168 22.0 155 27.4 17 14.7 710 26.5
60–69 188 24.6 164 29.0 22 19.0 654 24.4
70–79 158 20.7 90 15.9 25 21.6 400 14.9
80–84 60 7.9 13 2.3 14 12.1 148 5.5
85+ 95 12.5 19 3.4 36 31.0 181 6.7
Not stated 1 0.1 0 0.0 0 0.0 5 0.2
Sex
Female 341 44.7 199 35.2 61 52.6 972 36.2
Male 417 54.7 363 64.2 55 47.4 1,693 63.1
Not stated 5 0.7 3 0.5 0 0.0 18 0.7
Race
American Indian/Alaska Native 4 0.5 0 0.0 0 0.0 13 0.5
Asian 6 0.8 5 0.9 0 0.0 17 0.6
Black or African American 128 16.8 103 18.2 19 16.4 620 23.1
Native Hawaiian/Other Pacific Islander 1 0.1 0 0.0 0 0.0 3 0.1
White 475 62.3 354 62.7 72 62.1 1,503 56.0
Multiple 1 0.1 1 0.2 0 0.0 2 0.1
Not stated 148 19.4 102 18.1 25 21.6 525 19.6
Ethnicity
Hispanic 43 5.6 17 3.0 3 2.6 192 7.2
Non-Hispanic 545 71.4 443 78.4 96 82.8 1,937 72.2
Not stated 175 22.9 105 18.6 17 14.7 554 20.6

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 2015: 31 complete reporting jurisdictions reported at least 90% of confirmed NNDSS cases to SLDSS: Alabama, Colorado, Connecticut, Florida, Georgia, Hawaii, Iowa, Kansas, Kentucky, Maine, Maryland, Michigan, Minnesota, Mississippi, Missouri, New Hampshire, New Mexico, New York City, New York State, North Dakota, Ohio, Pennsylvania, Rhode Island, South Carolina, Texas, 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 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, 2014.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, 2014.
Healthcare exposure certainty
Definite Possible Total
Facility type N % N % N %
Hospital 31 20.7 251 49.6 282 43.0
Long-term care facility 100 66.7 72 14.2 172 26.2
Clinic 0 0.0 128 25.3 128 19.5
Multiplef 17 11.3 36 7.1 53 8.1
Otherg 0 0.0 8 1.6 8 1.2
Not stated 2 1.3 11 2.2 13 2.0
Total 150 100 506 100 656 100

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 2014: 31 complete reporting jurisdictions reported at least 90% of confirmed NNDSS cases to SLDSS in 2014: Alabama, Alaska, Colorado, Connecticut, Florida, Georgia, Iowa, Kansas, Kentucky, Maine, Maryland, Michigan, Minnesota, Mississippi, Missouri, New Hampshire, New York City, New York State, North Dakota, Ohio, Pennsylvania, Rhode Island, South Carolina, Texas, 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 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 two or more healthcare facilities.
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 2015.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, 2015.
Healthcare exposure certainty
Definite Possible Total
Facility type N % N % N %
Hospital 21 17.6 307 47.7 328 43.0
Long-term care facility 87 73.1 83 12.9 170 22.3
Clinic 0 0.0 184 28.6 184 24.1
Multiplef 9 7.6 50 7.8 59 7.7
Otherg 0 0.0 17 2.6 17 2.2
Not stated 2 1.7 3 0.5 5 0.7
Total 119 100 644 100 763 100

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 2015: 31 complete reporting jurisdictions reported at least 90% of confirmed NNDSS cases to SLDSS: Alabama, Colorado, Connecticut, Florida, Georgia, Hawaii, Iowa, Kansas, Kentucky, Maine, Maryland, Michigan, Minnesota, Mississippi, Missouri, New Hampshire, New Mexico, New York City, New York State, North Dakota, Ohio, Pennsylvania, Rhode Island, South Carolina, Texas, 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 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 two or more healthcare facilities.
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 2014.f

Table 6a. Number of reported confirmed cases of Legionnaires’ disease by hospitalization, outcome, and exposure category—SLDSS, complete reporting jurisdictions, 2014.
Exposure category
Healthcare
(Total = 656)
Travel
(Total = 449)
Assisted or senior living
(Total = 129)
None of these
(Total = 2,153)
N % N % N % N %
Hospitalization
Yes 622 94.8 422 94.0 126 97.7 2,083 96.7
No 29 4.4 16 3.6 2 1.6 41 1.9
Not stated 5 0.8 11 2.4 1 0.8 29 1.3
Outcome
Death 78 11.9 18 4.0 13 10.1 150 7.0
Still ill 67 10.2 45 10.0 12 9.3 181 8.4
Survived 441 67.2 335 74.6 88 68.2 1,545 71.8
Not stated 70 10.7 51 11.4 16 12.4 277 12.9

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 2014: 31 complete reporting jurisdictions reported at least 90% of confirmed NNDSS cases to SLDSS: Alabama, Alaska, Colorado, Connecticut, Florida, Georgia, Iowa, Kansas, Kentucky, Maine, Maryland, Michigan, Minnesota, Mississippi, Missouri, New Hampshire, New York City, New York State, North Dakota, Ohio, Pennsylvania, Rhode Island, South Carolina, Texas, 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 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 2015.f

Table 6b. Number of reported confirmed cases of Legionnaires’ disease by hospitalization, outcome, and exposure category—SLDSS, complete reporting jurisdictions, 2015.
Exposure category
Healthcare
(Total = 763)
Travel
(Total = 565)
Assisted or senior living
(Total = 116)
None of these
(Total = 2,683)
N % N % N % N %
Hospitalization
Yes 722 94.6 537 95.0 110 94.8 2,585 96.3
No 30 3.9 18 3.2 4 3.4 70 2.6
Not stated 11 1.4 10 1.8 2 1.7 28 1.0
Outcome
Death 88 11.5 21 3.7 11 9.5 173 6.4
Still ill 106 13.9 67 11.9 16 13.8 347 12.9
Survived 499 65.4 425 75.2 82 70.7 1,868 69.6
Not stated 70 9.2 52 9.2 7 6.0 295 11.0

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.

cSupplemental Legionnaires’ Disease Surveillance System (SLDSS).
dComplete reporting jurisdictions for 2015: 31 complete reporting jurisdictions reported at least 90% of confirmed NNDSS cases to SLDSS: Alabama, Colorado, Connecticut, Florida, Georgia, Hawaii, Iowa, Kansas, Kentucky, Maine, Maryland, Michigan, Minnesota, Mississippi, Missouri, New Hampshire, New Mexico, New York City, New York State, North Dakota, Ohio, Pennsylvania, Rhode Island, South Carolina, Texas, 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 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 7. Number of reported confirmed cases of Legionnaires’ disease by diagnostic testing methoda and yearb—SLDSS,c United States, 2014 and 2015.

Table 7. Number of reported confirmed cases of Legionnaires’ disease by diagnostic testing method and year—SLDSS, United States, 2014 and 2015.
2014 2015 Total
N % N % N %
Diagnostic testing method
Urinary antigen test 3,454 97.5 4,231 98.1 7,685 97.9
Serology 9 0.3 4 0.1 13 0.2
Culture 127 3.6 180 4.2 307 3.9
Culture site
Respiratory secretiond 111 87.4 152 84.4 263 85.7
Blood 2 1.6 3 1.7 5 1.6
Lung biopsy 3 2.4 7 3.9 10 3.3
Pleural fluid 2 1.6 2 1.1 4 1.3
Other 0 0.0 8 4.4 8 2.6
Not stated 9 7.1 8 4.4 17 5.5
Culture species
L. pneumophila 74 58.3 112 62.2 186 60.6
Serogroup 1 29 65 94
Serogroup 2 0 1 1
Serogroup 3 1 0 1
Serogroup 4 1 0 1
Serogroup 5 0 1 1
Serogroup 6 4 0 4
Serogroup 12 3 0 3
L. longbeachae 2 1.6 1 0.6 3 1.0
Serogroup 1 1 0 1
L. micdadei 3 2.4 1 0.6 4 1.3
L. parisiensis 0 0.0 2 1.1 2 0.7
Serogroup 1 0 2 2
L. bozemanii 1 0.8 0 0.0 1 0.3
L. feeleii 1 0.8 2 1.1 3 1.0
Other or not stated 46 36.2 62 34.4 108 35.2

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 Legionella 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 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.