Surveillance Report 2016-2017

^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.

Figure 2. Number of reported confirmed cases of Legionnaires’ disease^a by month^b and year^c—NNDSS,^d 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 incidence^a rates of reported confirmed cases of Legionnaires’ disease^b by jurisdiction of residence^c—NNDSS,^d United States, 2016.^e,f

^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 incidence^a rates of reported confirmed cases of Legionnaires’ disease^b by jurisdiction of residence^c—NNDSS,^d United States, 2017.^e,f

^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’ disease^a by jurisdiction of residence^b and year^c—NNDSS,^d 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).

^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 incidence^a rates of reported confirmed cases of Legionnaires’ disease^b by demographic characteristics and year^c—NNDSS,^d United States, 2016 and 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 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’ disease^a by age group and year^b—NNDSS^c and SLDSS,^d 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’ disease^a by sex and year^b—NNDSS^c and SLDSS,^d 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’ disease^a by race^b and year^c—NNDSS^d and SLDSS,^e 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’ disease^a by ethnicity and year^b—NNDSS^c and SLDSS,^d 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 legionellosis^a by syndrome and completeness of jurisdictional reporting^b—SLDSS,^c United States, 2016.^d

^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 legionellosis^a by syndrome and completeness of jurisdictional reporting^b—SLDSS,^c United States, 2017.^d

^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 category^a—SLDSS,^b complete reporting jurisdictions,^c 2016.^d

^aExposure categories are not mutually exclusive. A patient may report multiple exposures in the 10 days before date of symptom onset. Exposure categories:

^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 category^a—SLDSS,^b complete reporting jurisdictions,^c 2017.^d

^aExposure categories are not mutually exclusive. A patient may report multiple exposures in the 10 days before date of symptom onset. Exposure categories:

^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 category^a and year^b—SLDSS,^c complete reporting jurisdictions,^d 2016 and 2017.

^aExposure categories (categories are not mutually exclusive):

^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 category^a—SLDSS,^b complete reporting jurisdictions,^c 2016.^d

^aExposure categories (categories are not mutually exclusive):

^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 category^a—SLDSS,^b complete reporting jurisdictions,^c 2017.^d

^aExposure categories (categories are not mutually exclusive):

^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-associated^a Legionnaires’ disease by healthcare facility type and healthcare exposure certainty^b—SLDSS,^c complete reporting jurisdictions^d, 2016.^e

^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:

^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-associated^a Legionnaires’ disease by healthcare facility type and healthcare exposure certainty^b—SLDSS,^c complete reporting jurisdictions,^d 2017.^e

^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:

^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 category^c—SLDSS,^d complete reporting jurisdictions,^e 2016.^f

^aHospitalization for treatment of Legionnaires’ disease.

^bOutcome at time of case reporting.

^cExposure categories (categories are not mutually exclusive):

^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 category^c—SLDSS,^d complete reporting jurisdictions,^e 2017.^f

^aHospitalization for treatment of Legionnaires’ disease.

^bOutcome at time of case reporting.

^cExposure categories (categories are not mutually exclusive):

^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 hospital^a by age group and year^b—SLDSS,^c complete reporting jurisdictions,^d 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 death^a by age group and year^b—SLDSS,^c complete reporting jurisdictions,^d 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 method^a and year^b—SLDSS,^c United States, 2016 and 2017.

^aMore than one type of test might apply. Laboratory criteria for diagnosis include the following for confirmed cases:

^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.