Oregon dysentery outbreak: 7 new cases reported in February so far

Seven new cases of Shigella, which can cause dysentery, have been reported in Oregon, health officials told FOX TV Stations.

Data for February have yet to be finalized but officials said the current trend represents a decline compared to the number of cases reported in January. 

Oregon’s outbreak

The backstory:

Cases of dysentery have been on the rise in Oregon since 2012.

The cases spread from Multnomah County to the Portland Metro areas in the summer of 2024. Throughout 2024, high case counts reflected two separate outbreaks of different strains of Shigella.

"The cases that we are seeing in 2025 are the result of transmission of a strain of Shigella sonnei strain that was introduced into Oregon in the spring of 2024," the spokesperson told FOX TV Stations.

What caused the outbreak in Multnomah? 

Dig deeper:

Health officials said there are several ways the Shigella bacteria spread throughout the county. 

• Some cases are contracted through international travel to lower-resource countries (less than 20%). 
• Among cases without international travel, fecal-oral spread through intimate (including sexual) contact may account for between half and more than two-thirds of all cases.
• About one-third to half of cases in the past year have been in people experiencing either homelessness or housing instability.  
• We have also identified spread among housed and unhoused social groups who use drugs.

The cases of Shigella are being spread between people rather than from one outbreak source, such as a restaurant, the spokesperson explained. 

How many cases are in Oregon? 

By the numbers:

There are 197 total cases nationally with this particular strain.

Sixty-one percent of the cases have been in Multnomah County.

There are at least 14 distinct subclusters, which means that there are several pathways of transmission within different groups of people.

In 2024, there were 158 confirmed cases in Multnomah County. In January 2025 alone, there were 40 new cases reported.

These numbers do not include the newest February cases as the data has not been finalized yet. 

What is Shigella? 

Dig deeper:

Shigella bacteria cause shigellosis, which is an illness that impacts the intestines, according to the Mayo Clinic. 

Shigella can cause a range of systems, including, but not exclusively, dysentery.

Other symptoms can also include: 

• Fever
• Stomach pain
• Diarrhea

How to stop the spread

Since the most common source of transmission for Shigella is human to human among several subgroups, "there is no single, easy answer to stop all illness from spreading," according to the spokesperson. 

What's next:

The Multnomah County Health Department provides educational resources to teach people about avoiding the transmission of any disease.

"They counsel people to avoid preparing food, limit sexual contact, and stay out of pools and other communal water bodies for at least two weeks after symptoms stop. People who work in food, childcare or healthcare facilities are restricted from work until they test negative," the spokesperson said.

For unhoused people, the department can provide additional support through short-term housing, which health officials explained is the "best intervention for reducing spread." 

Other prevention tips include: 

• Frequent handwashing
• Throw away soiled diapers in a covered, lined garbage bin
• Disinfect diaper-changing areas right after use
• Avoid ingesting water from ponds, lakes or untreated pools
• Avoid sexual contact with anyone who has been suffering from diarrhea or recently recovered

Who is at risk?

Most people can recover from dysentery within a few days. However, if it goes untreated for a prolonged period, it can be fatal, according to the Cleveland Clinic. 

The people who are most at risk of suffering from serious complications of dysentery include: 

• Young children
• People over 50
• Dehydrated or malnourished people

OregonHealthNews