Cyclosporiasis in Houston: Latest numbers for illness that causes 'explosive diarrhea'

Houston-area health officials say cyclosporiasis cases have topped 30 this summer, but investigators still have not identified a common source for the parasite that can cause watery diarrhea, sometimes described as explosive.

What officials reported

The Houston Health Department has confirmed 16 cyclosporiasis cases in the city of Houston. Harris County Public Health reported 18 additional cases in the county, bringing the local total to more than 30.

Officials said they have not found an increased trend in the Houston-Harris County region compared with past years, and they have not identified a source linking the local cases to one another or to cases elsewhere in the country.

Texas Department of State Health Services said the state had at least 48 cyclosporiasis cases that matched the CDC outbreak case definition between May 1 and July 6.

What cyclospora is

Cyclospora cayetanensis causes cyclosporiasis. The infection can lead to watery diarrhea, along with other gastrointestinal symptoms, and it is typically acquired through contaminated food or water. It is not usually spread directly from person to person.

Cyclospora infections often rise in the warmer months, especially from May through August. Public-health officials also note that the number of confirmed cases may be lower than the true number because not everyone seeks testing or medical care.

What investigators are watching

The main unanswered question is what food, water, or other exposure is driving the Houston-area cases. Health departments will continue summer investigations, and reporters are watching for any restaurant, produce, or commodity link that could clarify the source.

For now, the public-health message is simple: Houston and Harris County are seeing confirmed cases, but the source remains unknown while officials continue to track whether the local total rises further this summer.