Why Is This Important?

Legionellosis refers to infections caused by Legionella species of bacteria. It includes both Legionnaires' Disease, a severe form of pneumonia, and Pontiac Fever, a flu-like illness that is usually self-limiting. Legionella is a naturally occurring bacteria commonly found in warm water sources such as large plumbing systems, hot water tanks, cooling towers, hot tubs, respiratory equipment, and decorative fountains. Disease transmission is not person-to-person. Instead, a person must breath in water droplets, mist, or vapor contaminated with the bacteria to become infected. Those at greatest risk of developing legionellosis are elderly persons, current and former smokers, persons with chronic lung diseases, and immunocompromised persons. Legionellosis has been a reportable disease in New Jersey since 2003.

Definition

Confirmed reported cases of legionellosis in New Jersey (both Pontiac Fever and Legionnaires' Disease) per 100,000 population

Data Sources

• Communicable Disease Reporting and Surveillance System (CRDSS), Communicable Disease Service, New Jersey Department of Health
  (http://www.nj.gov/health/cd/reporting/cdrss/)
• U.S. Census Bureau
  (https://www.census.gov/)

How the Measure is Calculated

How Are We Doing?

The crude rate during 2019-2023 was 2.9 cases per 100,000 New Jersey residents. (Due to small case counts, NJ reports the most recent 5-year period of data.)

How Do We Compare With the U.S.?

According to the CDC, reported cases of Legionnaires' disease have been increasing since the early 2000s, with a peak in 2018. While reported cases dropped during the first year of the COVID-19 pandemic, they rebounded nationally starting in 2021.^[https://www.cdc.gov/legionella/php/surveillance/index.html 1]^ The most recent report from CDC shows that from 2000 through 2019, a total of 82,352 confirmed Legionnaires' disease cases were reported from 52 U.S. jurisdictions. The crude national incidence rate peaked in 2018 at 3.04 cases per 100,000 population and increased 6.5-fold from 0.42 per 100,000 persons in 2000 to 2.71 per 100,000 persons in 2019. There were 9,933 confirmed Legionnaires' disease cases reported nationally in 2018 and 8,890 cases reported in 2019. National data for 2019 may be incomplete due to the COVID-19 pandemic.^[https://www.cdc.gov/legionella/health-depts/surv-reporting/2018-19-surv-report-508.pdf 2]^

Health Program Information

More information about Legionellosis can be found at [https://www.nj.gov/health/cd/topics/legion.shtml].

Footnote References

1. [https://www.cdc.gov/legionella/php/surveillance/index.html Legionellosis Surveillance and Trends], CDC, 2024. 2. [https://www.cdc.gov/legionella/health-depts/surv-reporting/2018-19-surv-report-508.pdf Legionnaires' Disease Surveillance Summary Report, United States, 2018-2019], CDC, 2022.