German officials announced on Sunday that locally grown beansprouts may be the cause of the "world's largest" E.coli outbreak that has killed at least 22 people, sickened more than 2,000 across Europe and is now suspected in four cases here in the United States.
All four U.S. patients visited Hamburg, Germany, in May, according to officials with the Centers for Disease Control and Prevention, or CDC.
Health officials say the massive enterohemorrhagic E. coli outbreak can cause bloody diarrhea and a toxin that damages the kidneys. The time from eating the contaminated food to the beginning of symptoms is typically three to four days.
Though cases have now been reported in 12 European countries and now the United States, nearly all have occurred among people with recent travel to northern Germany or who received visitors from that region, reports the Robert Koch Institute, Germany's national epidemiologic agency.
"In the other countries outside of Germany in Europe and in the United States, the persons who became ill were exposed in Germany and became ill in their home countries after exposure," said Dr. Chris Braden, director of Foodborne, Waterborne, and Environmental Diseases at the Centers for Disease Control and Prevention.
"We are continuing to monitor these cases closely. The risk of person-to-person transmission is low."
The bean sprouts possibly responsible for the massive Escherichia coli outbreak were reportedly grown in the northern part of Germany and health officials suspect that the Hamburg harbor festival that took place in May, drawing more than 1.5 million visitors from Germany and other countries across Europe, may have aided in the spread of the disease, officials from Lower Saxony state announced at a news conference Sunday.
The European Centre for Disease Prevention and Control reports that more than two thirds of cases have been in adult women.
"The source of the outbreak is under investigation, but contaminated food seems the most likely vehicle of infection," the Stockholm-based European Centre for Disease Prevention and Control said in a statement.
"More than 250 different foodborne illnesses have been described in scientific literature," said Dr. Lonnie J. King with the Centers for Disease Control and Prevention U.S. Department of Health and Human Services.
"Most of these diseases are caused by a variety of bacteria, viruses, and parasites. Some foodborne illnesses are poisonings, caused by harmful toxins or chemicals that have contaminated the food."
David Elder, director of regional operations for the Food and Drug Administration, said produce in the United States "remains safe, and there is no reason for Americans to alter where they shop, what they buy, and where they eat. The U.S. food supply is not in jeopardy."
Elder did say that the FDA established import controls within 24 hours of the E.coli health advisory from German officials.
"The FDA has increased its surveillance of cucumbers, fresh tomatoes, raw salads, and lettuce from Spain and from Germany," Elder said.
"When any of these products are presented for import into the United States, the FDA will sample and analyze them in our laboratories."