January 8, 2021

Updated January 11, 2021

The Multnomah County Health Department notified neighbors in the immediate vicinity of a North Portland apartment building where Legionnaires’ Disease has been detected to be aware of any signs of illness and how to lower risk in their homes and buildings.

Multnomah County is alerted to, and tasked with, investigating outbreaks of reportable diseases. On Jan. 5, the County Communicable Disease investigative team and Environmental Health investigators responded to Rosemont Court, 597 North Dekum St, after multiple people became ill with pneumonia. Their illness was identified as Legionnaires’ Disease. The Communicable Disease investigations team identified the building’s water supply as the likely source. 

Six residents have been found to have Legionnaires’ Disease, and another four residents are presumed to have the illness based on symptoms. One person who spent time at a property very close to Rosemont Court has also been found to have Legionnaires’ Disease. 

Five people have been hospitalized with Legionnaires’ Disease, including one person who died. By Monday only two individuals were still in the hospital.

The County moved almost 100 residents temporarily into motels until the building’s water system is disinfected. The Health Department is continuing to contact and test those residents, with Northwest Housing Alliance staff onsite for client support. Residents are receiving food through Meals on Wheels and County Emergency Management.

The County and Portland Water Bureau have given neighbors information about how to minimize any risk from the bacteria in their homes and buildings. The Health Department is working with Northwest Housing Alternatives which owns Rosemont Court to assure proper cleaning of the building plumbing system to remove any remaining Legionella bacteria and retest the water. The Legionella bacteria is found naturally in fresh water, but can cause health problems if it gets into a building’s water supply and multiplies - usually from a very thin sludge in pipes or fixtures or standing warm water. 

Legionnaires’ Disease is not known to spread from person-to-person. And most healthy people exposed to Legionella do not get sick. But for people at increased risk, breathing in very small droplets of water with the bacteria can lead to severe pneumonia.

People at increased risk for infection include the elderly, smokers, those with chronic diseases such as COPD or diabetes, and the immunosuppressed. For those who get symptoms, the first to appear are usually flu-like (fever, tiredness, muscle aches, and headache). Signs of a serious Legionella lung infection (pneumonia) include cough and chest pain. Many people sick with Legionella also have diarrhea. 

Legionella outbreaks have been rare in Multnomah County. The Communicable Disease investigations team is working closely with the Portland Water Bureau, Oregon Health Authority, and Centers for Disease Control to make sure residents of Rosemont Court and surrounding properties are confident in the safety of their water.

People in the building with questions or symptoms can call the County at 503-988-3406. 

For more information on Legionnaires’ Disease.


About Legionella

What is Legionella?

Legionella is a germ found naturally in fresh water, but can cause health problems if it gets into a building’s water supply. Breathing in very small droplets of water with legionella can lead to severe lung infection (pneumonia). Legionnaires’ does not spread from person-to-person.  Some people get a more mild illness with this bacteria - more like a flu.

What are the symptoms of Legionnaires’ disease?

Symptoms of Legionnaires’ Disease are typically:

  • Cough

  • Shortness of breath

  • Fever

  • Muscle aches

  • Headaches

Legionnaires’ disease can also be associated with other symptoms such as diarrhea, nausea, and confusion.  People with certain medical conditions may be at higher risk for developing Legionnaires’ Disease. They are:

  • Over age 50 

  • Smoking (current or historical)

  • Chronic lung disease, such as emphysema or COPD

  • Immune system disorders due to disease or medication

  • Systemic malignancy

  • Underlying illness, such as diabetes, renal failure, or hepatic failure

How does Legionella exposure happen?

People get sick from Legionella by breathing in small water droplets containing bacteria, not from drinking the water or contracting it from other people. Legionella can grow in plumbing systems when the water is warm, it grows best between 77 – 108 degrees fahrenheit, and has low levels of disinfectant. Common ways people breathe in water droplets with Legionella are from a cooling tower, during showering, hot tub use, or exposure to decorative fountains.

Large buildings that have complex plumbing systems are at a much greater risk to Legionella growth.

Should I test my water for Legionella?

The Portland Water Bureau does not recommend testing your home plumbing for Legionella. Legionella is best controlled by properly maintaining your water system by keeping your water heater temperature hot, performing routine maintenance and cleaning your faucets and showerheads every few months.

Portland Water Bureau Recommendations for Maintaining Building Water Quality

The Portland Water Bureau controls microorganisms, including Legionella, with chlorine and by maintaining the distribution system to deliver safe and reliable drinking water to your property. Once water enters a home or building, the resident, property owners, or building manager is responsible for maintaining water quality in the home or building plumbing system. Below are steps that should be taken to control Legionella in building plumbing.

Owners or managers of large buildings
  • Develop and implement a water management program. Water management programs help you maintain your building water quality to reduce the risk of Legionella growth and spread. Use these two industry-standard resources when developing your water management plan:

  • Check your hot water system. Set your water heater to at least 140 degrees Fahrenheit. When flushing hot water taps, run the water until it reaches its highest temperature.

  • If you're using less water in your large building during the pandemic, you may need to flush or run all water outlets at least weekly. The goal is to refresh all the water in the building pipes with fresh water from the water mains underneath the street. Follow guidance from the Environmental Protection Agency on how to flush the water in your building.

Residents of Single-Family Homes

The risk of exposure to Legionella in a single-family home is relatively low but there are steps you can take to protect your family from Legionella exposure. These and more steps you can take can be found in the Portland Water Bureau’s Water Quality at Home Guide.

  • Maintain water heaters at 140 degrees: Caution! 140 degrees fahrenheit is very hot. Take steps to prevent scalding risk at that temperature. You or a plumber can install anti-scald valves or faucets to prevent burns.

  • Follow the water heater manufacturer’s recommendations for routine maintenance to reduce the growth of Legionella and extend the life of your water heater.

  • Regularly clean your faucet aerators and shower heads every few months. Legionella can build up and grow in your faucet aerator.

Where can I learn more?