The United States has stepped up surveillance of some imported fresh vegetables and raw salad greens, but there are no signs the U.S. food supply has been tainted by a deadly E.coli bacteria that has sickened thousands in Europe, officials said on Sunday, according to Reuters. The number of suspected U.S. cases involving the E.coli bacteria remained at four on Sunday, all of whom had recently visited Hamburg, Germany, officials said. "Right now there have been no reports of any additional suspected cases" in the United States, Centers for Disease Control and Prevention spokeswoman Lola Russell told Reuters. The rare strain of E.coli has infected people in 12 countries, and has killed 22 people and made more than 2,000 ill. German-grown beansprouts and other sprouts could be the source of the deadly outbreak, German officials said. There were no indications the U.S. food supply has been tainted by E.coli, Food and Drug Administration spokesman Siobhan DeLancey told Reuters. However, as a safety precaution, the FDA said it was conducting increased surveillance of fresh tomatoes, cucumbers, lettuce and raw salads imported from areas of concern. But officials said countries in the European Union are not a significant source of fresh produce for the United States. The CDC said three suspected cases of a type of kidney failure associated with E.coli infections -- hemolytic uremic syndrome (HUS) -- had been identified in Massachusetts, Michigan and Wisconsin. A fourth suspected case of diarrhea caused by the E.coli is under investigation, the CDC said. Symptoms of E.coli infections include severe stomach cramps, diarrhea and vomiting. Symptoms of the HUS kidney failure, which usually develop a week after diarrhea begins, include decreased frequency of urination, fatigue and losing pink color to skin and membranes due to anemia, the CDC said.
