(HealthDay)—The ongoing outbreak of infection with the foodborne cyclospora parasite has now reached 400 cases and spread to 16 states and New York City, according to the latest U.S. Centers for Disease Control and Prevention report issued Friday.
The source or sources of the nationwide outbreak has not yet been located, although health officials at two of the hardest-hit states, Iowa and Nebraska, say they have traced local outbreaks to an as-yet-unnamed salad mix.
In a posting on its website, the CDC said that it "will continue to work with federal, state and local partners in the investigation to determine whether this conclusion applies to the increase in cases of cyclosporiasis in other states. It is not yet clear whether the cases from all of the states are part of the same outbreak."
Prior outbreaks of cyclospora infection have typically been caused by tainted produce, the agency noted.
While no one has died from cyclosporiasis, "at least 22 persons reportedly have been hospitalized in five states," the CDC said. Most people got sick between mid-June through early July.
One expert said that while cyclospora can make people very ill, it is not usually life-threatening.
"On the infectious disease scale, this ranks well below the more notorious and dangerous ailments like E. coli and salmonella," said Dr. Lewis Marshall Jr., chairman of the outpatient services at Brookdale University Hospital and Medical Center, New York City.
"It is unlikely to be fatal, but certainly can make one's life miserable," he said. "Symptoms include crampy abdominal pain, watery diarrhea, loss of appetite, bloating, nausea, fatigue, fever, headache and body aches."
According to the CDC, cases have now been reported from Arkansas, Connecticut, Florida, Georgia, Illinois, Iowa, Kansas, Louisiana, Minnesota, Missouri, Nebraska, New Jersey, New York City, New York State, Ohio, Texas and Wisconsin.
Cases of cyclosporiasis, which is caused by a single-celled parasite and can trigger diarrhea and stomach cramps, have been mounting through the month of July, said Dr. Monica Parise, chief of the parasitic diseases branch of the U.S. Centers for Disease Control and Prevention. The cyclospora parasite cannot be spread from person to person; it has to be ingested via contaminated water or foods such as fruit and vegetables.
"It can be pretty miserable, because it can give diarrhea that can last for days," Parise said.
The first reported cases occurred in Iowa, which has been hardest hit with 146 people falling ill so far. The first cases came in late June, with more infections reported through July.
Other states reporting large numbers of infections are Nebraska, with 81 cases, and Texas, with 113 cases.
It takes about a week for people who are infected to become sick.
Marshall said there may be more cases of cyclospora infection out there than people realize. It is possible, "that most occurrences go unreported as many people wouldn't recognize the symptoms as any different than a common stomach bug," he explained.
Dr. Thomas Frieden, CDC director, urged people who have suffered from diarrhea for longer than a couple of days to be tested for cyclospora.
"If not treated, symptoms can last from a few days to a month or longer, go away and then return later," Marshall said. "Cyclospora can be treated with an antibiotic combination of trimethoprim-sulfamethoxazole [Bactrim]."
The best option, however, is to avoid the bug altogether.
"The safest way to protect oneself and one's family is to always rinse fresh produce under water, and even put vegetables in a cold water bath ahead of time to properly clean them," Marshall advised.
One expert stressed that the wash-your-produce rule includes pre-packaged salads.
"Wash all your fruits and salads before ingesting," said Dr. Salvatore Pardo, vice chairman of the emergency department at Long Island Jewish Medical Center in New Hyde Park, NY. "My hunch is the public does not do this to "prepackaged" salad, which is normally purchased for convenience and dumped into the bowl since it tends to be free from particles—dirt, sand, critters—one would normally find in locally picked ingredients."
Earlier outbreaks of cyclospora have been traced back to fruits and vegetables imported from tropical regions like Latin America and Southeast Asia, where the parasite is common, Parise said.
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For more information on cyclospora, visit the U.S. Centers for Disease Control and Prevention.