Two cases of Legionnaires’ disease were recently reported in August 2022 from the section of Hamilton Township, Mercer County, served by Trenton Water Works (TWW). Two additional cases were reported, respectively in April 2022 and December 2021. Of the four, one individual has died.
Legionnaires’ disease is a type of pneumonia that people can get after breathing in aerosolized water (small droplets of water in the air) containing Legionella bacteria. You cannot get Legionnaires’ disease by drinking water that has Legionella. Less commonly, people can get sick when water containing Legionella is aspirated into the lungs while drinking (“goes down the wrong pipe”).
The New Jersey Department of Health (NJDOH) receives approximately 250–350 reports of Legionnaires’ disease each year throughout New Jersey. Public health departments routinely conduct disease surveillance to identify suspected clusters or outbreaks. When an outbreak is identified, impacted individuals are notified so they are aware of steps they can take to reduce their risk of Legionnaires’ disease.
The Hamilton Township Division of Health continues to work closely with NJDOH to investigate these cases. This is part of a larger ongoing investigation to determine potential sources of Legionella contributing to the higher burden of Legionnaires’ disease in Hamilton Township. Health officials continue to conduct surveillance for Legionnaires’ disease in other municipalities served by TWW.
As part of these ongoing efforts, the Hamilton Township Division of Health and NJDOH recruited 20 homeowners from Hamilton Township to voluntarily have their homes tested for Legionella. Water samples collected from more than half of the homes served by TWW identified the presence of Legionella, including in samples of the cold water entering homes. It is possible for Legionella to enter buildings and homes when receiving treated drinking water. However, health officials are concerned about the number of homes with Legionella in areas serviced by TWW. There is concern that Legionella may be present in other buildings and homes in the area, particularly in the areas of Hamilton Township served by TWW.
Hamilton Township and NJDOH are partnering with the New Jersey Department of Environmental Protection (NJDEP) and TWW to investigate factors that may be promoting the growth of Legionella bacteria and to evaluate actions that can be taken to reduce Legionella in the system. Investigators are also assessing if the other municipalities served by TWW are impacted.
“I want to thank Hamilton’s Division of Health, NJDOH, and NJDEP for their joint and thorough investigation into the causes of Legionnaire’s disease here in Hamilton,” said Mayor Jeff Martin. “This has been an issue for many years and their tireless work will hopefully reveal a cause for the high number of cases here in the Township – specifically those in the TWW service area.”
NJDOH recommends that all homeowners and building owners follow best practices to maintain their household and building water systems. However, health officials are especially urging residents and business owners in Hamilton Township served by TWW to take actions to reduce the risk of Legionella growth in their household and building plumbing. Recommendations for homeowners and building owners are available below.
It is not known whether individuals with Legionella detected in their home are more likely to develop Legionnaires’ disease, but there is no safe amount of Legionella, and individuals at increased risk for Legionnaires’ disease are especially urged to follow best practices for home plumbing system maintenance and safe uses of water.
It is rare for a healthy person exposed to Legionella to become sick with Legionnaires’ disease. However, people who are 50 years or older, especially those who smoke, or those with certain medical conditions, including weakened immune systems, chronic lung disease or other chronic health conditions, are at increased risk for Legionnaires’ disease.
Symptoms of Legionnaires’ disease include cough, shortness of breath, fever, muscle aches, and headaches, which are similar to symptoms caused by other respiratory infections, including COVID-19. Legionnaires’ disease can be fatal but is treatable with antibiotics. It is important that anyone who thinks they have symptoms of Legionnaires’ disease contact their health care provider and seek medical evaluation.
The Hamilton Township Division of Health and NJDOH want to remind healthcare providers to maintain a high index of suspicion for Legionnaires’ disease when evaluating patients for community-acquired and healthcare-associated pneumonia, especially among residents of Hamilton Township. This is important to ensure patients receive appropriate and timely treatment. Appropriate testing for Legionnaires' disease includes use of the urinary antigen test and collection of a lower respiratory specimen.
“There are simple precautions that residents can take to help protect themselves – such as regularly flushing water at their taps, cleaning their showerheads, and maintaining their water heaters,” said State Epidemiologist Dr. Tina Tan. “Additionally, home and car air-conditioning units do not use water to cool the air, so they are not a risk for Legionella growth.”
According to NJDOH, residents, particularly those at high risk, can follow recommended steps to decrease the risk of Legionella exposure and best practices to limit the growth of Legionella in household water systems and devices:
- Avoid high-risk activities. If you are at an increased risk for Legionnaires’ disease, consider avoiding hot tubs, decorative fountains, power washing, or similar activities, which may generate increased amounts of aerosols or mist. A conversation with your healthcare provider may help you assess your individual level of risk based on underlying health conditions and co-morbidities. Your healthcare provider may recommend that you consider installing specialty biological 0.2-micron filters on your showerhead if you are severely immunocompromised, reside in Hamilton Township, and receive water from Trenton Water Works.
- Maintain in-home medical equipment. If using medical equipment that requires water for use or cleaning such as non-steam generating humidifiers, CPAP or BiPAP machines, nasal irrigation devices such as Neti Pots, and attachments for nebulizers, follow manufacturer’s instructions for use and maintenance. This often includes using sterile water instead of tap water in the device.
- Clean and/or replace your showerheads and faucet aerators (screens) per manufacturer’s instructions whenever buildup is visible. This is particularly important if you haven’t cleaned your showerheads or faucet aerators recently. Cleaning might require you to remove the showerhead and hose and soak in a solution (such as white vinegar or a bleach solution) to remove buildup. If using chemicals, follow instructions found on the back of the bottle for safe use.
- Keep your water heater set to a minimum of 120°F. This temperature will reduce Legionella growth and avoid potential for scalding (hot water burns). Setting the heater to a higher temperature may better control Legionella growth, especially if you have household members at increased risk for Legionnaires’ disease. However, if the temperature is set to greater than 120°F, make sure you take extra precautions to mix cold and hot water at the faucet and shower to avoid scalding. If you have household members at increased risk of scalding, such as young children or older adults, you may consider installing a thermostatic mixing valve. A mixing valve allows your water to be stored at a higher temperature within your water heater to help kill bacteria while eliminating concerns with water being too hot at sinks or showers. If you decide to install a mixing valve, be sure to follow manufacturer’s instructions for routine cleaning and maintenance to avoid bacteria growth within the valve. Consider consulting with a licensed plumbing professional and ensure you are following your local codes and ordinances for home plumbing repairs.
- After cleaning showerheads and faucet aerators and increasing the temperature of the water heater, thoroughly flush the water at each tap (e.g., sink, showerhead) for 20 minutes. Try to minimize exposure to splashing and mist generation, for example, by leaving the room while the water is running.
- Conduct routine flushing. Sinks and shower taps that are not used often can increase the risk of Legionella growth in other areas of the home. Let your faucets and showers run for at least three minutes when they have been out of use for more than a week. Minimize exposure to splashing and mist generation, for example, by leaving the room while the water is running. Additionally, you may consider flushing your water following any water disruption to your home, such as low pressure or discoloration, resulting from a water main break or nearby hydrant flushing.
- Follow manufacturer’s instructions for maintaining your water heater and expansion tank, including periodic flushing, draining, and removal of sediment. If manufacturer’s instructions are unavailable, seek advice from a licensed professional.
- Clean and/or replace all water filters per manufacturer’s instructions. All whole-house (e.g., water softeners) and point-of-use filters (e.g., built-in refrigerator filters) must be properly maintained.
- Drain garden hoses and winterize hose bibs. Detach and drain the hose, shut the water valve off inside the home, and drain the pipe when not in use for the season.
- Follow manufacturer’s instructions for maintaining your hot tub. Ensure disinfectant levels (e.g., chlorine) and maintenance activities (e.g., cleaning, scrubbing, replacing the filter and water) are followed. For more information, be sure to review CDC’s recommendations for residential hot tub owners found here: https://www.cdc.gov/healthywater/swimming/residential/index.html.
- Operate and maintain your indoor and outdoor decorative fountains according to manufacturer’s instructions to limit your exposure to Legionella. Household members at increased risk for Legionnaires’ disease should avoid exposure to decorative fountains. If manufacturer’s instructions for cleaning and maintenance are not available, minimum cleaning frequency recommendations can be found in CDC’s Legionella Control Toolkit available at: https://www.cdc.gov/legionella/downloads/Control-Toolkit-Decorative.pdf.
- Remove, shorten, or regularly flush existing dead legs. Plumbing renovations can lead to the creation of dead legs, a section of capped pipe that contains water but has no flow (or is infrequently used). For future renovations, ensure your plumber avoids creating dead legs.
RECOMMENDED ACTIONS FOR BUILDING OWNERS
- Complete this quick yes/no worksheet to determine if your building, or certain devices in your building, need a Water Management Program. Resources to help you develop a Water Management Program and for Legionella control in common sources of exposure are available at NJ Department of Health’s Legionella https://www.nj.gov/health/cd/topics/legion.shtml
- Store hot water at temperatures above 140°F and ensure hot water in circulation does not fall below 120°F (or at highest temperature allowable by local regulations and codes). Install thermostatic mixing valves as close as possible to fixtures to prevent scalding while permitting circulating hot water temperatures above 120°.
- Clean and maintain water system components. This includes devices such as thermostatic mixing valves, aerators, showerheads, hoses, filters, water heaters, storage tanks, and expansion tanks, regularly per manufacturer instructions.
- Flush hot and cold water at all points of use (faucets, showers, drinking fountains) at least weekly to replace the water that has been standing in the pipes. Healthcare settings and facilities that house vulnerable populations should flush at least twice a week.
- Remove dead legs or, where unavoidable, make them as short as possible. Where a dead leg (a section of pipe capped off with little or no water flow) cannot be avoided, it should be flushed regularly to avoid water stagnation. This may require the installation of a drain valve.
- Monitor water quality parameters such as temperature, disinfectant residuals, and pH regularly. Adjust frequency of monitoring based on stability of values. For example, increase frequency of monitoring if there is a high degree of measurement variability. Pay particular attention to water quality parameters following a water disruption event, such as low pressure or discoloration, resulting from a water main break or nearby hydrant flushing.
- Safely operate and conduct regular maintenance of cooling towers to protect staff, visitors, and the adjacent community from exposure to Legionella. Use a Water Management Program to establish, track, and improve operation and maintenance activities.
- Follow recommendations from the NJ Department of Health when reopening your facility following a prolonged shutdown or reduced operation due to the COVID-19 Pandemic. Recommendations are available at: bit.ly/2XxlBaw
ABOUT LEGIONNAIRES’ DISEASE AND LEGIONELLA
Legionnaires’ disease is a type of pneumonia (lung infection) caused by Legionella bacteria. Legionella is a type of bacteria found naturally in freshwater environments such as lakes and streams and becomes a health concern when it enters and grows inside human-made water systems. People can get Legionnaires’ disease by breathing in aerosolized (small droplets) water containing Legionella. Aerosolized water can come from plumbing systems and devices such as cooling towers (part of the cooling system for large buildings), hot tubs, cooling misters, and decorative fountains. Less commonly, people can get sick by aspiration of tap water containing Legionella. This happens when water accidently goes into the lungs while drinking (“goes down the wrong pipe”). People at increased risk of aspiration include those with swallowing difficulties. Home A/C units do not use water to cool, so these home units do not aerosolize water and are not a risk for Legionella growth. Legionnaires’ disease is generally not spread person to person. Additional information regarding Legionnaires’ disease and Legionella can be located at NJDOH’s website.
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