(CBS NEWS) -- An outbreak of the food-borne illness cyclosporiasis, which can leave victims with symptoms lasting for nearly two months, has infected more than 300 people in 10 states, including two cases in Missouri and one case in Illinois.
The Iowa Department of Public Health said Monday that at least 71 cases of the infection caused by a rare parasite have been reported in that state.
Cyclosopriasis is an intestinal illness caused by the cyclospora parasite. People get sickened after eating contaminated food or water. Symptoms commonly include watery diarrhea, loss of appetite, weight loss, cramping, bloating, gas, nausea and fatigue. Vomiting and low-grade fever could occur less commonly, the Centers for Disease Control and Prevention says.
The diarrhea could last an average of 57 days if untreated. The standard treatment prescribed is the combination antibiotic trimethoprim/sulfamethoxazole.
The source of the current outbreak is unknown, but cyclosporiasis is often traced to eating fresh fruits and vegetables, the health department said. Most of the illnesses began in mid to late June, with many people reporting they are still ill or have suffered relapses.
At least 35 people in Nebraska were also sickened by cyclosporiasis as of Friday, in an outbreak that's likely related, CBS affiliate KOLN-TV in Lincoln, reported. The outbreak is mostly confined to Douglas County -- the Omaha area -- in the eastern part of the state, according to the Associated Press.
Nebraska epidemiologist Dr. Thomas Safranek told the AP last week that fresh vegetables are likely to blame, but the investigation is ongoing.
The Mayo Clinic reports that before 1996, sporadic cases of cyclospora infection turned up only in people who traveled to developing countries or had a weakened immune system, such as from HIV. But, since 1995, Mayo reports that lettuce, fresh basil and imported raspberries have been implicated in cyclospora outbreaks in North America.
Even careful washing isn't enough to eliminate the parasite that causes the infection, according to the Mayo Clinic.
Every year, about 48 million Americans, or roughly one in six people, get sick from eating contaminated food.
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