Health officials in Oregon are reportedly battling dozens of cases of dysentery amid a years-long rise in the highly contagious, diarrhea-inducing disease.

There have been 40 confirmed cases of dysentery, also known as shigellosis, in the Portland area since January, the Oregonian and local station KOIN reported, citing the Multnomah County Health Department, which did not immediately respond to HuffPost’s request for comment.

That is more than double the number of dysentery cases seen during the same time last year. Cases of the disease have been rising steadily over the last few years: There were 158 cases in 2024, 96 in 2023 and 43 in 2022, according to Multnomah County health data shared with local news outlets.

In the U.S., dysentery is commonly associated with 19th-century pioneers traveling on the Oregon Trail — thanks in large part to the classic “Oregon Trail” video game, in which players could die of ailments like dysentery, cholera and measles. (The latter is also experiencing a U.S. resurgence).

However, it remains a common and serious disease in other parts of the world, with around 1.7 billion cases annually, according to the Cleveland Clinic.

Symptoms of the bacterial infection include bloody diarrhea, fever, painful stomach cramps, nausea and vomiting. Without proper treatment, dysentery can be fatal, especially for young children, people 50 and older, and those suffering from dehydration or malnutrition.

Though dysentery is capable of spreading through parasitic infection as well (in what’s called amoebic dysentery), the cases in Oregon are reported to be bacterial, which usually spreads through food or water contaminated by fecal matter from an infected person, according to the Cleveland Clinic.

This can happen if food is prepared by someone who doesn’t wash their hands due to poor hygiene or lack of access to proper sanitation. Dysentery can also spread by drinking or swimming in contaminated water, or through sexual contact.

In the Portland area, the spread of dysentery has been linked to increased homelessness and methamphetamine or opiate usage, health officials said.

“Lacking housing creates a context that can increase the risk of multiple kinds of infectious disease,” the Multnomah County Health Department said in a statement to KOIN. “When you don’t have housing, it is harder to prevent infectious disease and harder to access care to treat disease compared to if you are housed.”

The health department said it is working to provide short-term housing to people who test positive for dysentery to boost access to hygiene and sanitation and reduce Shigella bacteria’s spread.