Massachusetts Sees Rise in Cyclosporiasis amid US Spike

Massachusetts is experiencing a significant surge in cyclosporiasis cases, with state health officials reporting 147 confirmed infections so far in 2026 — nearly double the 74 cases recorded during the same period last year . The sharp increase, which saw cases climb from 32 in June to 104 in July, reflects a broader national trend as the U.S. grapples with what health experts describe as a record-breaking cyclospora season . While Massachusetts has been spared the thousands of cases seen in Midwestern states, health officials are closely monitoring the situation, noting that some local cases have been linked to recalled iceberg lettuce distributed to food service locations in the state .

Massachusetts Case Counts and Historical Context

The Massachusetts Department of Public Health (DPH) reported nine cases in May, followed by 32 in June, before the count more than tripled to 104 in July . Two additional cases were reported before the typical seasonal start date of May 1, bringing the total to 147 as of August 1 .

While this year's numbers are elevated, DPH officials emphasize that they remain within the state's historical range. Between 2016 and 2025, annual cyclospora cases in Massachusetts fluctuated from a low of 23 to a high of 211, with the 2019 outbreak representing the recent peak . That year, state officials traced 211 cases to contamination in several restaurants, making it an outlier in the past decade .

"The number of cases remain within the state's historical range," a DPH spokesperson noted, adding that officials are not seeing evidence of large outbreaks taking place within Massachusetts .

Links to the National Outbreak and Taylor Farms Recall

Federal health officials have linked the national cyclospora surge to shredded iceberg lettuce supplied by Taylor Farms and sourced from central Mexico . In July, the company issued a voluntary recall of its iceberg lettuce products distributed to 27 states, including Massachusetts . The recall covered 25 shredded lettuce and salad mix products sold under eight different brand codes, with "best by" dates extending through August 3 .

Taylor Farms stated it had stopped sourcing from the implicated farm in Mexico, which represents less than 1% of the U.S. iceberg lettuce supply, and suspended all distribution of iceberg lettuce from the region indefinitely . Sysco, the nation's largest food distributor, halted distribution of all Taylor Farms iceberg lettuce products sourced from Mexico and instructed customers to destroy them .

In Massachusetts, DPH epidemiologists have identified "a few small case clusters among residents, some with apparent links to the lettuce" . However, officials stress that no local sources of contaminated produce have been identified, and there is no evidence of a widespread outbreak originating within the state .

National Scope and Severity

According to the CDC, the number of cyclosporiasis cases has topped 22,000 across 47 states, with more than 500 hospitalizations and two deaths reported in Michigan . Both individuals who died had "significant underlying health conditions that may have been impacted by cyclosporiasis and dehydration," according to the Michigan Department of Health and Human Services .

The outbreak has been particularly severe in Midwestern states, with Michigan reporting over 11,000 cases . Health officials have identified the largest cluster in Southeast Michigan, where more than 1,500 cases were reported by early July . The CDC has also linked New Hampshire to the national outbreak, with 33 confirmed cases as of late July, including 17 linked to exposure at Cheshire Medical Center in Keene .

Federal health officials initially linked the surge to shredded iceberg lettuce served at Taco Bell restaurants in Michigan, Ohio, Indiana, West Virginia, and Kentucky . Taco Bell stated it had "worked swiftly to voluntarily remove the product from restaurants" and removed the affected ingredient from its supply chain nationwide .

Understanding Cyclosporiasis and Prevention

Cyclosporiasis is an intestinal illness caused by the microscopic parasite Cyclospora cayetanensis, which is spread through food or water contaminated with human feces . The parasite is particularly challenging to detect and prevent because it adheres firmly to produce surfaces. Dr. Catherine Brown, an epidemiologist with the Massachusetts DPH, described it as a "sticky parasite" that is difficult to wash off .

The most common symptom is watery diarrhea, which can be frequent and sometimes explosive . Other symptoms include loss of appetite, weight loss, abdominal cramping, bloating, nausea, and prolonged fatigue . Symptoms typically begin about one week after exposure, and if left untreated, the illness can persist for up to a month or longer, following a remitting-relapsing course .

Health officials recommend thorough food handling precautions. "You want to make sure you're washing everything with soap and water if you are preparing anything that's fresh produce or fresh fruit. Anything that you can peel — that improves safety," Brown advised . Cooking food to 158 degrees Fahrenheit kills the parasite . The infection is treatable with antibiotics, and most healthy individuals recover with proper hydration .

Seasonal Patterns and Outlook

Cyclosporiasis cases typically rise during spring and summer months in the U.S., with the seasonal peak occurring from May 1 through the end of August . While case counts are particularly high this year, some experts believe the national outbreak may have reached its peak. "We've seen a lot of scattered cases, a few linked cases that we could identify as a cluster, but nothing that we would classify as a large outbreak," said Dr. Larry Madoff, DPH Medical Director .

Brown noted that while Massachusetts has not yet seen a clear decline in cases, the national trend suggests the season may be on the downswing. "We can't identify the exposure for every single one of our cases, right? But the ones we can, those exposures happened a month ago, and so, history suggests that we're on the downward side of this," she said . However, she cautioned that additional cases are still expected to be reported due to delays in diagnosis and reporting. "I wouldn't be surprised if we eventually exceed our most, the last 10-year peak, which was in 2019, but we are not seeing thousands of cases at this point the way many parts of the Midwest are," she added .

The Massachusetts DPH will provide its next case count update in the first week of September .