Elliot Olsen has regained millions for people harmed by Legionnaires’ disease. If you or a family member were sickened in this Portland Legionella outbreak, please call Elliot at (612) 337-6126 for a free consultation.

A Portland Legionella outbreak has sickened at least 13 residents of Rosemont Court, an affordable senior housing complex, with Legionnaires’ disease since January. One victim died.

The outbreak, the source of which is still under investigation after six months, prompted the evacuation of nearly 100 residents, who were relocated to hotels while Northwest Housing Alternatives (NHA), which runs Rosemont Court, worked to stop the outbreak.

Portland Legionella outbreak: Efforts futile

Legionnaires’ disease develops when microscopic water droplets tainted by Legionella bacteria are inhaled. Legionella grow best in warm water, and they are found primarily in human-made environments.

Multnomah County health officers and Portland Water Bureau staff worked with the NHA to empty water lines, add chlorine and a disinfecting system, and install filters to shower heads and faucets.

Those mitigation efforts, however, did not work.

Portland Legionella outbreakPortland Legionella outbreak: March return

Residents moved back into the building in early March, “and unfortunately since then, we’ve now had our third confirmed case of Legionella in a Rosemont resident,” said Dr. Jennifer Vines, lead health officer for Multnomah County and neighboring counties. NHA is now relocating anyone who wants to move.

Legionella pneumophila, the bacteria that causes both Legionnaires’ disease and Pontiac fever, is found just about anywhere there is fresh water. It is very likely that every person has, at some point, inhaled this bacteria. A few might develop Pontiac fever, but that is merely a mild, flu-like illness and does not affect the lungs.

When Legionella is inhaled by someone who is immune-compromised, or has lung disease, or who is elderly, it can cause Legionnaires’ disease, a quick-moving lung infection with a fatality rate of 10 percent, according to the Centers for Disease Control and Prevention (CDC).

What does that mean? A victim often doesn’t know they’ve been infected with Legionella until it’s already taken hold.

Said Dr. Vines: ”When you find out you have a problem because someone is very ill … you don’t want to be in that position.”

Portland Legionella outbreak: Nearby illness

In January, a case of Legionnaires’ disease was found in a resident of a building near Rosemont Court, but authorities were unable to connect it to the outbreak.

”We worked with the Portland Water Bureau, the Oregon Health Authority, and the Centers for Disease Control,” Vines said. “It’s really difficult with a bacteria that’s just naturally found in the environment.”

That’s the problem: Legionella is present in low levels in most fresh water. So techniques usually used to look for a bacteria aren’t very effective.

Portland Legionella outbreak: Tricky bacteria

How does one distinguish between a false positive and a real positive?

“Water samples can be tricky to interpret for that reason,” Vines said.

Similarly, the presence of the Legionnaires’ bacteria in a water system doesn’t mean people, even those who are immune compromised, will get sick. The human body is inhospitable to bacteria, so one usually needs to inhale a lot to get infected.

Legionella outbreaks occur when water stagnates, like it sometimes does in rarely-used pipes, and the bacteria start to form colonies. Eventually, chunks of the colony can slough off, travel through pipes, and be dispersed through the air by faucets and showers. Kill the colony, and presumably, the outbreak will stop.

But these colonies difficult to kill. Many of the most common ways to sterilize pipes fail, so if a chlorine treatment kills only the top layer of the colony, it will regrow quickly.

Portland Legionella outbreak: Hard to kill

That’s why point-of-use filters attached to faucets and showers at Rosemont Court – and elsewhere – have become the go-to solution for Legionella-caused illnesses.

Those filters, however, can slow water pressure and make it hard to use.

”The three more recent cases look like maybe an improper use of filters could have been a part of it,” Vines said. Water is an important tool, and “we certainly heard frustration from residents who had bad experiences with the filter slowing flow.”

It’s unclear if that led people to use the filters improperly, said Vines, but she has been working with Rosemont Court’s maintenance team to install filters with a higher flow in apartment units in the building where people have chosen to stay.