Legionnaires’ Disease Surveillance Summary Report, United States 2018–2019

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

^aCrude incidence of cases per 100,000 population (number of confirmed Legionnaires’ disease cases reported that year divided by postcensal population estimate for that year times 100,000 population).
^bCases of disease due to Legionella are reported to NNDSS as legionellosis, which includes Legionnaires’ disease, Pontiac fever, and extrapulmonary legionellosis, but are referred to as Legionnaires’ disease in this figure (because almost all legionellosis cases reported in the United States are Legionnaires’ disease cases).
^cBased on year the case was reported to CDC.
^dNational Notifiable Diseases Surveillance System (NNDSS).
^eJurisdictions may report cases of any case status to NNDSS, but only confirmed cases of Legionnaires’ disease from the 50 U.S. states, the District of Columbia, and New York City are included in this figure, with the exceptions noted below. National case counts published in the MMWR use the same criteria and exceptions.

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

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

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

^aCases of disease due to Legionella are reported to NNDSS as legionellosis, which includes Legionnaires’ disease, Pontiac fever, and extrapulmonary legionellosis, but are referred to as Legionnaires’ disease in this table (because almost all legionellosis cases reported in the United States are Legionnaires’ disease cases).
^bJurisdiction of the patient’s “usual residence” at the time of disease onset.
^cBased on year the case was reported to CDC.
^dNational Notifiable Diseases Surveillance System (NNDSS).

^aCrude incidence of cases per 100,000 population (number of confirmed Legionnaires’ disease cases reported that year divided by postcensal population estimate for that year times 100,000 population).
^bCases of disease due to Legionella are reported to NNDSS as legionellosis, which includes Legionnaires’ disease, Pontiac fever, and extrapulmonary legionellosis, but are referred to as Legionnaires’ disease in this table (because almost all legionellosis cases reported in the United States are Legionnaires’ disease cases).
^cBased on year the case was reported to CDC.
^dNational Notifiable Diseases Surveillance System (NNDSS).
^eOther race includes individuals that did not identify with races listed.

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

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

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

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

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

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

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

^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 2019: 38 complete reporting jurisdictions reported at least 90% of confirmed NNDSS cases to SLDSS in 2019: Alabama, Alaska, Arizona, California, Colorado, Connecticut, Delaware, District of Columbia, Florida, Georgia, Hawaii, Idaho, Illinois, Indiana, Iowa, Kansas, Kentucky, Maine, Michigan, Minnesota, Missouri, Montana, Nebraska, Nevada, New Hampshire, New York (state), New York City, Ohio, Oregon, Pennsylvania, Rhode Island, Tennessee, Texas, Utah, Vermont, Virginia, Washington, and Wyoming.
^dBased on year of symptom onset in SLDSS. If onset date was not stated in SLDSS, case year for confirmed cases was determined by the following dates (in order of reporting): positive laboratory date (by either urinary antigen testing, culture, or 4-fold rise of antibody titer against Legionella pneumophila serogroup 1); date patient was hospitalized during treatment for Legionnaires’ disease; or date case was first reported to public health at any level.
^eCFR: Case fatality rate calculated as the number of reported confirmed Legionnaires’ disease case deaths divided by the number of patients with Legionnaires’ disease and the same exposure history.

^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 2018: 42 complete reporting jurisdictions reported at least 90% of confirmed NNDSS cases to SLDSS: Alabama, Alaska, Arizona, Arkansas, California, Colorado, Connecticut, Delaware, District of Columbia, Florida, Georgia, Hawaii, Illinois, Indiana, Iowa, Kansas, Kentucky, Maine, Maryland, Michigan, Minnesota, Mississippi, Missouri, Nebraska, New Hampshire, New York (state), New York City, North Carolina, North Dakota, Ohio, Oregon, Pennsylvania, Rhode Island, South Carolina, Tennessee, Texas, Utah, Vermont, Virginia, Washington, Wisconsin, and Wyoming.
Complete reporting jurisdictions for 2019: 38 complete reporting jurisdictions reported at least 90% of confirmed NNDSS cases to SLDSS in 2019: Alabama, Alaska, Arizona, California, Colorado, Connecticut, Delaware, District of Columbia, Florida, Georgia, Hawaii, Idaho, Illinois, Indiana, Iowa, Kansas, Kentucky, Maine, Michigan, Minnesota, Missouri, Montana, Nebraska, Nevada, New Hampshire, New York (state), New York City, Ohio, Oregon, Pennsylvania, Rhode Island, Tennessee, Texas, Utah, Vermont, Virginia, Washington, and Wyoming.

^aExposure categories (categories are not mutually exclusive):

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

^aExposure categories (categories are not mutually exclusive):

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

^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 2018: 42 complete reporting jurisdictions reported at least 90% of confirmed NNDSS cases to SLDSS in 2018: Alabama, Alaska, Arizona, Arkansas, California, Colorado, Connecticut, Delaware, District of Columbia, Florida, Georgia, Hawaii, Illinois, Indiana, Iowa, Kansas, Kentucky, Maine, Maryland, Michigan, Minnesota, Mississippi, Missouri, Nebraska, New Hampshire, New York (state), New York City, North Carolina, North Dakota, Ohio, Oregon, Pennsylvania, Rhode Island, South Carolina, Tennessee, Texas, Utah, Vermont, Virginia, Washington, Wisconsin, and Wyoming.
^eBased on year of symptom onset in SLDSS. If onset date was not stated in SLDSS, case year for confirmed cases was determined by the following dates (in order of reporting): positive laboratory date (by either urinary antigen testing, culture, or 4-fold rise of antibody titer against Legionella pneumophila serogroup 1); date patient was hospitalized during treatment for Legionnaires’ disease; or date case was first reported to public health at any level.
^fMultiple indicates more than one type of healthcare facility.
^gOther facility includes locations such as outpatient laboratories and pharmacies.

^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 2019: 38 complete reporting jurisdictions reported at least 90% of confirmed NNDSS cases to SLDSS in 2019: Alabama, Alaska, Arizona, California, Colorado, Connecticut, Delaware, District of Columbia, Florida, Georgia, Hawaii, Idaho, Illinois, Indiana, Iowa, Kansas, Kentucky, Maine, Michigan, Minnesota, Missouri, Montana, Nebraska, Nevada, New Hampshire, New York (state), New York City, Ohio, Oregon, Pennsylvania, Rhode Island, Tennessee, Texas, Utah, Vermont, Virginia, Washington, and Wyoming.
^eBased on year of symptom onset in SLDSS. If onset date was not stated in SLDSS, case year for confirmed cases was determined by the following dates (in order of reporting): positive laboratory date (by either urinary antigen testing, culture, or 4-fold rise of antibody titer against Legionella pneumophila serogroup 1); date patient was hospitalized during treatment for Legionnaires’ disease; or date case was first reported to public health at any level.
^fMultiple indicates more than one type of healthcare facility.
^gOther facility includes locations such as outpatient laboratories and pharmacies.

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

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

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

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

^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 4-fold rise of antibody titer against Legionella pneumophila serogroup 1); date patient was hospitalized during treatment for Legionnaires’ disease; or date case was first reported to public health at any level.
^cSupplemental Legionnaires’ Disease Surveillance System (SLDSS).
^dRespiratory secretions include sputum, bronchial wash, bronchoalveolar lavage.