The health department says there have been 56 cases since May, including four cases in Harris County.
Cyclosporiasis is an intestinal illness caused by consuming food or water contaminated by the parasite.
The Texas Department of Health and Human Services said it is investigating after dozens of cases.
In Houston, health workers have recorded three cases since the beginning of summer.
Here are the symptoms you should look for:
Health officials are still investigating the source of the infections, but they recommend you thoroughly wash all fresh produce.
While reported cases of #Cyclosporiasis in Houston are currently fewer than last year, it's important to stay aware.— Houston Health Dept (@HoustonHealth) July 2, 2018
So far this year, there have been three cases reported in Houston. At this time last year, there were 18 reported. @CityofHouston @SylvesterTurner @HoustonOEM https://t.co/U2JCUhkxcY