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A parasitic infection that causes diarrhea has been detected in 34 states. Investigations into the cause of the spread are ongoing. Image Credit: Catherine McQueen/Getty
  • The CDC reports that a parasite that may cause explosive diarrhea is spreading around the U.S.
  • At least 34 states have reported cases of cyclosporiasis, with at least 6,148 cases occurring in Michigan.
  • Cyclosporiasis often spreads through contaminated food or water. The FDA is working with the CDC to identify the possible sources of the parasite.
  • A recent investigation linked lettuce sourced from Taylor Farms to Taco Bell to the outbreak, but the FDA says it was a false positive.

The Centers for Disease Control and Prevention (CDC) issued a warning of rising cases of cyclosporiasis, a parasitic infection that can cause watery, often explosive diarrhea, among other symptoms.

Cyclosporiasis is caused by the microscopic parasite Cyclospora. Symptoms of cyclosporiasis typically begin within 7 days of exposure to the parasite.

“CDC routinely tracks cyclosporiasis as part of ongoing surveillance; cases typically increase in the spring and summer months. Jurisdictions have reported an uptick in cases in the past several weeks. CDC is working with partners to investigate this increase,” a CDC spokesperson told Healthline.

The Food and Drug Administration (FDA) and the CDC are working to identify possible sources of the outbreak. According to recent investigations, produce such as leafy greens and lettuce could be a possible source.

This comes after the Food and Drug Administration (FDA) reported that testing of lettuce supplied by Taylor Farms de Mexico returned positive for Cyclospora. Taylor Farms issued a recall for iceberg lettuce sourced from central Mexico and voluntarily removed the product from the market.

However, the FDA has since then re-reviewed the sample results, and have determined that it was a false positive, due to the complexity in detecting Cyclospora.

Some Taco Bell locations had received the now-recalled lettuce, including but not necessarily limited to stores in Kentucky, Indiana, Michigan, Ohio, and West Virginia. As of July 17, Taco Bell said they are no longer using iceberg lettuce from Taylor Farms de Mexico.

According to the CDC, at least 34 states had been affected by the increased spread of cyclosporiasis as of July 13. These include:

  • Alaska
  • Arizona
  • Arkansas
  • California
  • Colorado
  • Connecticut
  • Florida
  • Georgia
  • Illinois
  • Indiana
  • Iowa
  • Kansas
  • Kentucky
  • Louisiana
  • Maryland
  • Massachusetts
  • Michigan
  • Minnesota
  • Nebraska
  • New Hampshire
  • New Jersey
  • New York
  • North Carolina
  • Ohio
  • Oklahoma
  • Pennsylvania
  • Rhode Island
  • Tennessee
  • Texas
  • Utah
  • Virginia
  • Washington
  • West Virginia
  • Wisconsin

At the time of the CDC report, Michigan had 501 to 900 cases. However, as of July 20, Michigan has now reported 6,148 cases.

According to the CDC, individuals who reported being unwell with the infection ranged from 2 to 95 years old, with an average age of 44. Approximately 56% of cases have been seen in females.

These individuals became ill after eating food in the United States. They did not report any travel in the 14 days preceding the onset of symptoms.

As of July 13, 440 people have also reported getting sick after consuming food or drink while traveling outside the United States in the 14 days before they got sick.

While there have been reports of hospitalizations from the infection, as of the CDC report, there have been no reports of death.

Most cyclosporiasis cases in the United States have emerged in Michigan.

A spokesperson for the Michigan Department of Health and Human Services (DHHS) told Healthline that the state had identified 300 cases as of July 2.

Typically, Michigan identifies only about 50 cases of cyclosporiasis per year. As of July 20, there have been 6,148 total cases reported in Michigan.

“MDHHS is working with [the] local health department in southeast Michigan to investigate [the] large and growing outbreak of cyclosporiasis, a diarrheal illness, to identify a common exposure,” said the DHHS spokesperson.

“The department is coordinating the multi-jurisdictional investigation, assisting in case interviews, and sharing information with the CDC and MDARD [Michigan Department of Agriculture & Rural Development]. At this time, the source or sources have not yet been identified.”

Symptoms and treatment for cyclosporiasis

While the main symptom of the infection is watery and often explosive diarrhea, other symptoms may include:

“The illness, untreated, can last for weeks, often in an on-and-off pattern. The major hazard is dehydration, which can cause problems for patients at the extremes of age, those with chronic medical conditions, and persons who are immunocompromised,” William Schaffner, MD, professor of the Division of Infectious Diseases at Vanderbilt University, told Healthline.

Treatment for cyclosporiasis typically includes a selection of antibiotics.

The parasite that causes cyclosporiasis generally spreads when you eat food that is already contaminated with feces.

It takes 1 to 2 weeks outside of the body for Cyclosporato become infectious after passing in a bowel movement. Because of this, transmission from person to person is unlikely.

It is not fully known how Cyclosporagets into food and water. The best way to prevent the infection is to avoid eating contaminated foods and drinking contaminated water.

“In recent years, outbreaks have occurred in the U.S. as a result of eating contaminated fresh produce, especially during the summer months,” said the DHHS spokesperson.

Practicing safe food handling can help avoid contamination. This includes:

  • Washing your hands with soap and water before and after handling and preparing raw fruits and vegetables.
  • Wash all fruits and vegetables under running water before cutting, cooking, or eating.
  • Scrub firm fruits and vegetables, like melons and cucumbers, with a clean produce brush.
  • Cut away any damaged or bruised areas before preparing and eating.
  • Refrigerate cut, peeled, or cooked fruits and vegetables as soon as possible, but within 2 hours.