Health officials are scrutinizing an uptick in cyclospora infection cases, a foodborne illness that prompts severe diarrhea, spreading across the United States. Numerous states have experienced an outbreak, with Michigan highlighting an unprecedented number, while others report elevated cases.
Cyclosporiasis arises from the microscopic parasite, Cyclospora cayetanensis. According to the Centers for Disease Control and Prevention (CDC), the infection primarily causes watery diarrhea, often accompanied by frequent and severe bowel movements. Previous outbreaks in the U.S. have frequently been linked to tainted fresh produce, with a heightened occurrence in summer.
States Reporting Cases
Recent data from the CDC and state health departments reveal confirmed cases in multiple states, including:
- Alaska
- Colorado
- Connecticut
- Florida
- Georgia
- Illinois
- Louisiana
- Massachusetts
- Michigan
- New Jersey
- New York
- North Carolina
- Ohio
- Pennsylvania
- Tennessee
- Texas
- Virginia
- Wisconsin
Michigan stands out with the highest confirmed cases, over 700, described as exceedingly irregular by state officials. They are investigating food consumption histories and grocery purchases to pinpoint a source.
As of early July, Ohio reported 177 cases, Texas noted 48, and other states like New York (120), North Carolina (141), and Illinois (110) showed increased case numbers or are delving into suspected clusters.
The CDC’s Observations
The CDC reports that instances of cyclosporiasis ascend during summer, generally between May 1 and August 31. The latest national surveillance update indicates 145 domestically acquired cases across 17 states from May 1 through June 16, involving 20 hospitalizations and zero fatalities.
These figures, published with delays, do not mirror recent state reports. Based on disclosed state case estimates, the total reported infections are expected to be markedly higher, albeit the CDC has yet to reveal an updated nationwide count.
The CDC states there is no clear evidence linking all reported cases to a singular national outbreak. Both federal and state investigators are examining various clusters to identify potential shared food sources.
Accuracy of Official Numbers
Public health experts note that many infected individuals never undergo laboratory tests or get medical attention, meaning official case numbers may not fully capture the extent of infections.
Further, lags between exposure, symptom onset, testing, and reporting imply surveillance data often follow actual outbreaks by several weeks.
Previously Linked Foods
Investigators have yet to identify the specific food responsible for current outbreaks. Historically, U.S. outbreaks have been associated with:
- Basil
- Cilantro
- Mesclun lettuce
- Bagged salad mixes
- Raspberries
- Snow peas
- Green onions (scallions)
Fresh produce often gets implicated due to contamination risks occurring before reaching consumers, via tainted irrigation water or other environmental elements. Person-to-person transmission is uncommon, as the parasite requires environmental maturation to become infectious.
Symptoms of Cyclospora
Symptoms generally begin around one week post-consumption of tainted food or water, with appearances ranging from two days to two weeks after exposure. Common symptoms include:
- Watery diarrhea
- Frequent severe diarrhea
- Stomach cramps
- Bloating
- Nausea
- Loss of appetite
- Fatigue
- Weight loss
Without treatment, symptoms can linger for several weeks, potentially improving before recurring.
Future Steps
The Food and Drug Administration, CDC, and state health departments are actively investigating probable contamination sources. To date, no specific grower, supplier, or food product has been identified.
Given the seasonal nature of cyclospora infections and standard reporting delays, further cases are anticipated in the coming weeks. Investigators aim to determine if current cases arise from one or several unrelated contamination incidents, not a unified national outbreak.