Cyclospora outbreak: What is causing the explosive diarrhea in US, can it be prevented, and is there a risk for India?

More than 30 states in the US have reported cases of Cyclosporiasis, with close to 5,000 cases nationwide so far. Michigan has been the worst-hit, with more than 3,300 cases reported since late May.

According to the Associated Press, the current cyclospora outbreak is already the nation's worst year for reported cases. The previous record was around 4,700 reported cases in 2019.

What is behind Cyclosporiasis outbreak?

What makes the outbreak concerning is the fact that health officials have not yet definitively identified what is causing the infections. In Michigan, officials say early information points to lettuce or salad greens as a possible culprit.

According to the US FDA, Cyclospora cayetanensis is a parasite that is so small it can only be seen under a microscope. When people eat food or drink water that’s contaminated with Cyclospora, they can get an intestinal illness called cyclosporiasis.

What is Cyclosporiasis

As the parasitic infection that causes what some describe as ‘explosive diarrhea’ continues to spread rapidly, here is what health experts have to say.

“Cyclospora (Cyclospora cayetanensis) is transmitted through the fecal-oral route, mainly by consuming food or water contaminated with human feces. Fresh produce such as lettuce, spinach, cilantro, basil, berries, and other raw vegetables have been implicated in outbreaks,” Dr. Nasiruddin G, Consultant in Internal Medicine at Fortis Hospital Cunningham Road, Bengaluru, said.

Unlike many other intestinal pathogens, Cyclospora is not usually spread directly from one person to another, because the parasite requires several days to weeks in the environment to become infectious after being excreted.

Should you stop eating raw veggies?

In the US, Taco Bell on Tuesday issued a statement saying it had “voluntarily and temporarily removed limited ingredients at select restaurants as a precautionary measure,” amid speculations that some veggies used by the fast food chain may have caused the spread.

When asked if people should avoid using veggies like lettuce, Dr. Nasiruddin said there is no recommendation for the general public to avoid lettuce or other leafy greens unless there is a specific food recall or public health advisory.

“The health benefits of eating fresh vegetables far outweigh the risk. Consumers should, however, purchase produce from reputable sources and practice good food hygiene,” he said.

Can you disinfect veggies at home?

Dr. Nasiruddin, however, pointed out that it was not easy to disinfect veggies if they are already contaminated by the Cyclospora parasite.

“Simply rinsing vegetables under running water helps remove dirt and may reduce some contamination, but it cannot reliably eliminate Cyclospora if the parasite is present. Household disinfectants, vinegar, salt water, or baking soda washes have not been proven to completely kill Cyclospora on fresh produce,” he explained.

According to Dr. Nasiruddin, the best preventive measures are:

Thorough washing under clean running water.

Peeling fruits and vegetables where possible.

Cooking produce when appropriate, as heat destroys the parasite.

Ensuring irrigation water and food handling practices are hygienic throughout the supply chain.

Will Cyclospora outbreak affect India?

On the question of whether the current Cyclospora infections in the US pose a larger risk, including in India, Dr. Nasiruddin said Cyclospora outbreaks are not uncommon in the country.

“Cyclospora infections do occur in India, particularly because the parasite is endemic in many tropical and subtropical regions. However, large foodborne outbreaks linked to commercially distributed produce are reported less frequently than in North America. Sporadic cases are likely underdiagnosed because routine stool microscopy may miss the parasite unless specifically looked for. Maintaining safe water supplies, proper sanitation, and good agricultural practices remains the cornerstone of prevention,” he said.