(COLORADO) — Colorado has seen an increase in Shigella cases, bacteria that can cause an infection in the intestines, along with some infections that are drug-resistant, according to the Colorado Department of Public Health and Environment (CDPHE).

According to Rachel Jervis, an Epidemiologist with the State Health Department, in 2022, Colorado reported 373 cases of Shigella, compared to the five-year average, which was about 250 cases.

“We are seeing cases, but not a particularly large number of them. Typically, we would see more Shigella in the summer months than winter months; though the end of 2022 is actually fairly high numbers for us,” said Jervis.

In late summer and fall of 2022, Colorado saw an increasing number of cases, some of which were associated with clusters and outbreaks, primarily along the Front Range, according to Jervis.

According to CDPHE, symptoms usually start one to two days after infection and last seven days.

Symptoms of Shigella

  • Diarrhea that can be bloody.
  • Fever.
  • Stomach pain.
  • Feeling the need to pass stool even when the bowels are empty.

According to CDPHE Shigella can spread easily.

Shigella is transmitted through the fecal-oral route. So what that means is people, have unintentionally, unknowingly consumed the feces of someone who’s been sick,” stated Jervis.

A person can become infected with Shigella in a number of ways.

“It can happen because an ill food handler had Shigella and prepared food for you. It can happen from changing the diaper of a child who’s sick and being household contacts or transmission through sex,” warned Jervis.

How does Shigella spread?

  • Getting Shigella on your hands and touching your mouth.
  • Eating food prepared by someone with a Shigella infection.
  • Swallowing recreational water, such as lake water or improperly treated swimming pool water.
  • Swallowing contaminated drinking water, such as water from a well that’s been contaminated with sewage or flood water.
  • Exposure to stool during sexual contact with someone with a Shigella infection or who has recently recovered from a Shigella infection.

Particular groups of people are becoming infected with Shigella in Colorado.

“So our recent Shigella cases have predominantly impacted adult men, and we’ve documented both sexual and other person-to-person transmissions,” stated Jervis.

Shigella, however, is a risk to anyone living in close quarters.

“The general message to everyone is, it’s really important to wash your hands well. And, if you have diarrheal illness, to stay home from work, particularly if you work in food handling, health care, or child care,” said Jervis.

Jervis said Shigella is a very small percentage of what’s causing diarrheal illness in our state. “It’s Norovirus season, that stomach bug that’s really common this time of year… And so we know that’s causing a lot of diarrhea and vomiting for people.”

Jervis clarified that the only way to confirm if someone has Shigella is to get laboratory testing, which is especially important for patients experiencing certain symptoms.

“…If it’s not going away, if your diarrhea is bloody, if you also have a fever; those are times when it’s really good to go see your doctor and hopefully get some testing to identify the source of your illness,” said Jervis.

Recently, the Centers for Disease Control and Prevention (CDC) also issued an alert for Shigella bacteria that appears to be resistant to antibiotics.

“So through the testing that our state public health lab and CDC do, we’re able to ascertain what drugs different Shigellas are resistant to. And in the past year, year and a half, we’ve seen an increase in drug resistance,” stated Jervis.

Jervis said it’s also important to note that many, probably even most people do not need antibiotic treatment for Shigella, as they will clear the infection on their own.

“However, for people who do need antibiotics, maybe they’re immunocompromised or for whatever reason, their illness has just been longer or severe, when they need antibiotics for that, doctors are finding that there are fewer antibiotics available to treat some of their patients with Shigella,” stated Jervis.

Jervis said one of the challenges with infections that spread person-to-person, is that once you have it in your community, it spreads easily.

“…Shigella is a pathogen that, it’s a very small infectious dose, it’s very little of the organism that you need to unintentionally ingest to become sick. So, once you sort of have ongoing person-to-person transmission, it’s very hard, if not near impossible, to totally stop it, and it’ll kind of gradually, gradually continue, unfortunately.”

That’s why Jervis said it is so vital for public health interventions to be conducted for those diagnosed.

“So every person who’s diagnosed with Shigella, public health, local or state, will attempt a public health interview, and we want to learn about your symptoms, see if we can identify where you got sick, the source of your illness, but also provide support to you to prevent making other people sick,” stated Jervis.

To learn more about Shigella bacteria or prevention efforts, click on the CDPHE link above.