Cases of the “explosive” diarrhea-causing parasite cyclosporiasis nearly tripled in Colorado over the past month, prompting renewed attention after related deaths were reported in Michigan.

Twenty-nine counties in Colorado have reported cases, according to the Colorado Department of Public Health and Environment.

Colorado has had 241 cases of cyclosporiasis since January, state data shows. Of the completed investigations, only 45 of the cases were acquired domestically. The vast majority, or 74%, reported international travel.

Several factors could account for the increased number of cases, including greater awareness because of outbreaks in other states.

“The case count alone does not indicate that an outbreak is occurring in Colorado,” Kayla Glad, a CDPHE spokesperson, said in an email.

To date, there have been four cases in Colorado that resulted in hospitalizations.

The state had 204 cases last year.

“Some of the increase also is probably associated with increased testing,” said Dr. Michelle Barron, senior medical director of infection prevention and control for UCHealth.

Barron added: “There may be a little bit of a testing bias.”

According to the Centers for Disease Control and Prevention (CDC), more than 6,700 laboratory-confirmed cases have been reported in 45 states since May 1, the start of the cyclosporiasis season, which typically runs through the end of summer.

But this doesn’t include the 11,500 cases reported by the Michigan Department of Health and Human Services.

Michigan reported the first deaths this week: two.

Colloquially referred to as “cyclo,” cyclosporiasis is a parasitic disease that infects the intestinal tract. 

The most common symptom is watery diarrhea with frequent “explosive” bowel movements, according to the state health department. Other symptoms can include loss of appetite, weight loss, increased gas, abdominal cramps, bloating, nausea and fatigue.

Vomiting, body aches, headache and other flu-like symptoms may also occur.

The incubation period is, on average, seven days, but ranges up to 14 days or longer. If left untreated, symptoms can linger for a month or longer.

Its cause is associated with ingesting contaminated food or water.

The parasite in stools is not considered infectious, meaning person-to-person spread is unlikely.

Cyclosporiasis is treated with antibiotics, rest and hydration.

Those with preexisting medical conditions could be at greater risk of complications related to dehydration, which the triple-digit heat could exacerbate.

“If they have underlying medical conditions, they should really see their doctor sooner rather than later,” said Dr. Kum Kap Foong, a Denver Health infectious disease physician and medical director of the Antimicrobial Stewardship Program.

Shredded iceberg lettuce supplied to Taco Bell by California-based supplier Taylor Farms, which has a facility in Colorado Springs, has been ​identified as a source of contamination in an outbreak in nine states that has sickened thousands of people in the U.S.

Taylor Farms initiated a recall last month of all iceberg lettuce sourced from central Mexico.

The best way to prevent cyclosporiasis is to avoid food or water contaminated with feces.

Those sickened nationally were between 1 and 98 years old. The median age is 44, with females accounting for nearly six in 10 cases.

Health officials have said that they believe the number of cases is likely higher because some may have recovered without medical intervention.

The CDC recommends washing hands with soap and water before and after handling or preparing raw fruits and vegetables.

Consumers should cut away damaged or bruised areas before preparing and eating, remove the outer layers and thoroughly wash fruits and vegetables, scrubbing firm produce such as melons and cucumbers with a clean produce brush.

Health officials do note that washing produce does not completely eliminate the risk.

Barron, with UCHealth, further recommends using a separate cutting board for produce and meat or cutting fruits and vegetables first.