The El Paso Department of Public Health is investigating seven reported cases of cyclosporiasis, the intestinal parasitic illness that causes explosive diarrhea, city officials said in a news release Monday.

While the cases meet the reporting criteria as either probable or confirmed, a common source of exposure has not been identified, and no evidence linking the reported cases to a single event, location or food source currently exists, officials said.

The public health department determined that five of the individuals who are believed to be infected reported having recently traveled to Mexico during the parasite’s incubation period. Three of them traveled to Cancún, one to Ciudad Juárez and one to La Cruz and Los Filtros, Chihuahua. Two others didn’t report recent travel.

Cyclosporiasis is not considered endemic to a specific geographic area, said Vanessa Casner, lead epidemiologist for the city of El Paso.

People can become infected by consuming food or water contaminated with the parasite. Symptoms may include watery diarrhea, loss of appetite, weight loss, stomach cramps, bloating, nausea, fatigue and a low-grade fever.  

The health department routinely investigates reportable diseases to identify potential public health concerns. El Paso health authority Dr. Hector Ocaranza said in the news release.

He said residents are encouraged to wash produce thoroughly, practice good hand hygiene, especially before handling food and after using the restroom, and to drink safe, treated water when traveling. If diarrhea or other gastrointestinal symptoms persist, people are encouraged to contact their doctor.

While thoroughly washing fresh fruits and vegetables is an important food safety practice and may help reduce risk, washing alone does not eliminate the parasite, Casner said. The only reliable way to kill cyclospora is by cooking food to an internal temperature of at least 158°F for several minutes, according to the Centers for Disease Control and Prevention. 

LEARN MORE: Parasite that causes explosive diarrhea detected in El Paso, but risk remains low

The health department last week confirmed to El Paso Matters the first case of cyclosporiasis in El Paso since July 2025 – one of the seven now being investigated.

The cases come as federal health officials remain focused on lettuce from Taylor Farms as the source of a multistate outbreak despite inaccurate test results reported over the weekend. 

Food and Drug Administration officials on Monday told reporters that the government erroneously reported a direct link between a sample of lettuce from Taylor Farms and the parasite that causes severe diarrhea. 

This undated photo taken through a microscope provided by the Centers for Disease Control shows cyclospora cayetanensis oocysts found in a fresh stool sample which had been prepared with a formalin solution and stained with safranin. (CDC via Associated Press)

Federal and state authorities have been investigating a rise in cases of the parasite, initially linking the outbreak in five states to lettuce served at Taco Bell locations. 

In addition to tracing the supply chain of lettuce, FDA staff have begun testing samples of produce coming across the U.S. border.

So far this year, cyclospora has sickened at least 1,645 people in the United States and hospitalized 141, according to the FDA and CDC. The agencies are investigating five separate clusters of illnesses, including the one traced to Taylor Farms.

The Associated Press contributed to this story.

Editor’s note: 11:30 a.m. July 21: This story has been updated with additional information on the investigation and precautions to avoid the parasite.