Sprouts were also identified as the source of the German outbreak. French officials have not yet determined if the two episodes are connected.

But public health experts in the United States said the new outbreak raised concerns that contaminated seeds from a common supplier might be the ultimate source of the E. coli bacteria. If those seeds are still in circulation, other outbreaks could occur.

The French health authorities said that seven of those who had become sick attended a charity event at a children’s play center in Bègles, a suburb of Bordeaux, on June 8. Most of the people who became ill recalled eating gazpacho garnished with sprouts.

French investigators traced the sprouts served at the event to seeds bought at a garden store chain, Jardiland, according to a news release from Frédéric Lefebvre, a secretary of state attached to the economy ministry.

Mr. Lefebvre said the seeds were supplied by a British company, Thompson Morgan. Although the link between the seeds and the illness had not been definitively established, he called on French retailers to pull the company’s seeds for fenugreek, mustard and arugula from shelves.

Efforts to contact Thompson Morgan on Friday were not successful. The company also distributes seeds in the United States. The German outbreak began in early May and has sickened more than 3,800 people, nearly 900 of them with a serious complication involving acute kidney failure. Nearly all the cases involved people who lived or had traveled in Germany.

German authorities have blamed the outbreak on bean sprouts grown by a German commercial sprouter, which shut down on June 5. American health experts said the French outbreak was worrisome because it suggested that the ultimate source of the deadly bacteria — a rare and highly virulent E. coli strain known as O104:H4 — had not been found and contained.

“If there’s no linear connection from the first outbreak, then the simplest and the most ominous explanation is there’s an upstream source and that’s very concerning because that stuff could still be being distributed,” said Dr. Phillip Tarr, a professor of microbiology at the Washington University School of Medicine in St. Louis.

Dr. Tarr said it was still too early to draw firm conclusions about the cause of the latest round of illnesses. He said it was possible, although unlikely, that someone sickened in the earlier outbreak had prepared food served at the event in France and so passed on the infection.

“Traceback here is absolutely critical because that killer organism could be sitting around viable and not contained,” he said.

William E. Keene, a senior epidemiologist at the Oregon Public Health Division, said it was urgent to find out if the seeds used by the German grower had come from the same source as the seeds linked to the French cases.

At least five of the French cases involved kidney failure, and tests on two of those people showed they were infected with the O104:H4 strain. The eight people infected in the Bègles area were adults, age 31 to 78. In addition, two children were sickened in another town and they were presumed also to have E. coli infections, although it was not clear if they had the same strain.

Article source: http://feeds.nytimes.com/click.phdo?i=76f07ff2988ff0b8ebf60ec7c866987b