NCDHHS Highlights Rise in Legionnaires’ Disease Cases in North Carolina

North Carolina Addresses Rising Legionnaires’ Disease Cases

The incidence of Legionnaires’ disease is on the rise both in North Carolina and globally, prompting the North Carolina Department of Health and Human Services (NCDHHS) to intensify public awareness efforts. The state witnessed an increase from 201 cases in 2024 to 310 cases in 2025.

Legionnaires’ disease is a severe form of pneumonia caused by the bacterium Legionella. This bacterium thrives in moist environments such as natural water bodies, wet soil, and poorly maintained artificial water systems like hot tubs, decorative fountains, and cooling towers.

Typically, individuals contract Legionnaires’ disease by inhaling mist or vapor tainted with Legionella. The disease does not spread from person to person. Most healthy people exposed to this bacterium do not fall ill, but certain groups are at higher risk, including:

• Individuals aged 50 and older
• Current or former smokers
• Individuals with chronic health issues such as lung disease, kidney failure, and diabetes
• People with weakened immune systems

Preventing Legionnaires’ disease primarily involves controlling the proliferation of Legionella in domestic and shared water systems. For home prevention, consider the following:

• Flush faucets or showerheads if unused for three or more days, or after plumbing work.
• Maintain and disinfect hot tubs according to the manufacturer’s instructions.
• Adhere to the manufacturer’s recommendations for using and cleaning in-home medical equipment like humidifiers and CPAP machines.
• Regularly clean and replace water filters as per the manufacturer’s guidelines.
• Drain garden hoses to prevent stagnant water; high-risk individuals might consider wearing a mask during gardening.
• Use proper windshield wiper fluid, as Legionella can grow in tanks if tap water is used.

In commercial buildings and healthcare facilities, particularly those with cooling towers, additional steps are advised. While no single action guarantees Legionella control, prioritizing water safety can protect the health of employees and guests:

• Monitor unoccupied floors or rooms, as low occupancy can reduce water flow, affecting disinfectant levels and water temperature. Refer to the CDC’s guidelines for hotel owners and managers.
• Ensure adequate disinfectant levels and appropriate water temperatures in the building’s water system. See CDC’s guidance on water monitoring.

• Store cold water below 77°F and hot water above 140°F.

• Properly maintain on-site hot tubs, which are susceptible to Legionella due to warm water and water jets. More information is available for public hot tub operators.
• Maintain decorative fountains and misters appropriately.
• Cooling tower operators should be vigilant as Legionella can grow in both open- and closed-circuit systems, especially after periods of inactivity. Key strategies include:

• Position towers at least 25 feet from buildings.
• Automate disinfectant use in cooling towers.
• Design piping systems to prevent stagnation.
• Operate cooling towers at the lowest feasible water temperature, ideally below 77°F.
• For further details, visit the CDC’s cooling towers module.

For additional information, please visit the NCDHHS Legionellosis webpage or contact your local health department.