Erie County’s cyclosporiasis outbreak has intensified, with county health officials reporting 68 new cases of the gastrointestinal disease July 20 and 21.
It brings the county’s total to 75 cases since the nationwide outbreak started in May.
Since cases are not required to be reported in Pennsylvania and some people develop mild symptoms, the actual number of infected people is likely higher, said Erin Mrenak, director of the Erie County Department of Health.
“There have been no hospitalizations among the county’s cases that we are aware of and no deaths,” Mrenak said.
Mrenak receives the county’s current case total from PA-NEDSS, Pennsylvania’s version of the National Electronic Disease Surveillance System. Health-care providers have been asked to report cases through PA-NEDSS.
Cyclosporiasis is caused by a microscopic parasite found in fresh produce. The illness’ main symptom is watery, explosive diarrhea that can last between a week and a month.
The current outbreak has been traced to national grower Taylor Farms. It has recalled several lettuce products, though an investigation into the exact source of the parasitic illness is still ongoing, USA Today reported.
“A pattern seems to be emerging among our cases that is similar to the nationwide trend,” Mrenak said. “Many, but not all, of the people have either consumed bagged lettuce or have eaten at Taco Bell.”
Taylor Farms had supplied lettuce to Taco Bell, but the restaurant chain removed the product from all of its locations July 17.
Long incubation period makes disease investigation difficult
Mrenak has transferred nurses and other county health department staff to help interview patients as part of the department’s disease investigation. It’s the first time she has done that since the county’s measles outbreak in spring 2025.
“The problem is that the disease’s incubation period is long, the average is about a week before symptoms appear, and it’s difficult for people to remember what they ate that long ago,” Mrenak said.
People have responded well to the standard treatment, Mrenak said. It’s a seven- to 10-day course of the antibiotic Bactrim, also known as Septra.
Best advice is to avoid bagged lettuce for now
It’s not known how much longer this outbreak will last. New cases will likely be reported, even with Taylor Farms’ recalls, since the incubation period is relatively long, Mrenak said.
“The best advice is probably avoid bagged lettuce for now and make sure to wash all of your produce, even if it has been previously washed,” Mrenak said. “If you have been sick with diarrhea for three to five days, you should contact your health-care provider.”
