The strain had been found in a stream in Frankfurt, in the German state of Hesse [AFP]

Health officials in Germany have confirmed that they have detected the first case of human-to-human spread of the deadly strain of the E. coli bacterium that has claimed the lives of almost 40 people.

Authorities say a woman working in a kitchen of a catering company near Frankfurt, in the state of Hesse, became infected with the bacterium after eating sprouts and passed it on to 20 people she prepared food for.

"Now we have the proof that in this case a human passed on the germ to the vegetables and then it was passed to other humans," Daniel Bahr, Germany's health minister, said on Saturday, during a visit to the Institute of Hygiene of the University Hospital in Muenster.

Cases began appearing at the start of May and the outbreak swelled to crisis level over the following three weeks, with the city of Hamburg at the epicentre.

On Saturday, Susanne Huggett, an infectious diseases expert at the Medilys laboratories at Hamburg's Asklepios Hospital, explained how the strain could be transmitted via food preparation.

"If someone has the disease and prepares food for others - and we know that for this infection just a small amount of bacteria is enough - then that food can get contaminated by the sick person," she said.

Strain in stream

Bahr has cautioned that even though the outbreak is waning after causing 39 deaths and sickening almost 3,000 people, further deaths are possible.

Officials on Friday said that the strain had been found in a stream in Frankfurt.

While officials say there are no consequences for the water supply, citizens in the state of Hesse are generally advised not to swim in local streams and rivers.

Test samples were being taken from a nearby sewage treatment plant to try to detect a possible source of the contamination.

Authorities say E. coli had been detected before in the 30km stream.

One local man said he was not surprised at the recent findings.

"Residents here have often intestinal problems and so they often visit the doctor. I believe this can have something to do with that," he said.

Further samples were being taken from the stream over the weekend, with results not expected until Monday.

French investigation

Meanwhile, French authorities are investigating two new suspected cases of E. coli linked to hamburger patties that have already sickened seven children in the country's north.

On Saturday, health authorities ordered a recall of 10 tonnes of the frozen beef patties produced in France and sold by the German supermarket chain Lidl, but said there was no link to a deadly outbreak of E. coli in Germany.

Xavier Bertrand, French health minister said two new patients were being examined for signs of the strain.

The regional health chief, Daniel Lenoir, said the two ate the same beef patties and later suffered severe diarrhea.

Seven children, between 18 months and 8 years old, were hospitalised with E. coli linked to the patties in northern France on Wednesday and Thursday.

Doctors at the Lille University Hospital in northern France told a news conference on Friday that one of the hospitalised children, a 2-year-old, needs breathing assistance and is being held in an artificial coma.

The child ate one of the beef patties, which had been only slightly browned, said Bertrand, urging parents to cook their meat thoroughly.

Symptoms

Regional Health Agency (ARS) officials in Lille said the children suffered from bloody diarrhoea, a symptom that also struck victims of the outbreak in Germany which has been blamed on infected bean sprouts.

They also became anaemic quickly and blood transfusions were required for four of the children. Three others suffered from renal failures severe enough to require dialyses, said Foulard.

"We are certain that this is not the same strain as the bean sprouts in Germany," Daniel Lenoir, the ARS head, said in Lille.

The children suffer from a syndrome that "may be the source of an acute renal failure", the ARS said, adding that the bacteria was a "rare type" which produces dangerous "Shiga" toxins.

Bertrand said a search was under way to determine the origin of the outbreak and stricter controls would be enforced at production sites.

Source: Agencies