Cyclospora Outbreak Spreads Across US, Nearly 300 Cases Reported

The source of a widespread outbreak of the intestinal illness cyclospora is still unknown as reports of rare infection spread to 11 US states.

As of Thursday, at least 285 people were confirmed with the stomach bug, including 18 people who have been hospitalized across three states, the Centers for Disease Control and Prevention (CDC) reported.

Earlier this week the CDC said confirmed cyclospora cases in Iowa, Nebraska, Texas and Wisconsin. The range of the infection has since spread to at least five other states. Georgia, Connecticut, New Jersey, Minnesota, and Ohio have also notified the CDC of cyclospora infections. Illinois and Kansas have each reported once confirmed case, but it is possible that the patients may have acquired in infection while out of state.

Cyclospora is an intestinal illness caused by the microscopic parasite Cyclospora cayetanensis. People may become infected with cyclospora after consuming food or water contaminated with the parasite, according to the CDC. The Food and Drug Administration (FDA) reports the parasite is unlikely to be transmitted from one person to another, which suggests that those infected consumed a contaminated food or beverage.

Barbara Herwaldt, a CDC medical epidemiologist, said previous cyclospora outbreaks have been traced to produce such as raspberries, basil, lettuce and snow peas, but as of now no specific food has been identified as the source of the outbreak.

It remains unclear whether each of the cases across the 11 states is part of the same outbreak. No common events, such as social gatherings, can be linked to all the patients. The most recent data available indicates that 96 percent of the cases are concentrated in three states: Iowa, Nebraska and Texas, with Iowa's 138 confirmed cases exceeding the combined total for Nebraska and Texas.

It typically takes about one week between being infected with cyclospora and the first signs of symptoms. The parasite infects the small intestine and "usually causes watery diarrhea, with frequent, sometimes explosive, bowel movements," according to the FDA.

Cyclospora infection is not thought to be life-threatening, though a spokesperson for the Nebraska Department of Health and Human Services said some infected residents dropped 25 pounds while fighting the illness.

Other symptoms include loss of appetite, weight loss, stomach cramping or bloating, flatulence, fatigue, and in some cases vomiting, headache, fever and other flu-like symptoms are observed. It is typical for the infected to observe their symptoms going away and later relapsing. Some people infected with the parasite do not show any symptoms.

If untreated, a cyclospora infection can last as long as 57 days, according to Ann Garvey, deputy state epidemiologist for the Iowa Department of Public Health.

Public health officials in Iowa and Nebraska suspect the outbreak in the states was a vegetable that was shipped into their territory, rather than a local product, according to the Wall Street Journal.

The FDA and CDC have both reported that they will make more information about the cyclospora outbreak public as it becomes available.