EU health officials say the rate of infection from the highly toxic strain of E coli, which has killed 19 people, has fallen in the past two days.
However, they have warned that it is unclear whether the decrease marks a permanent decline.
Germany has set up a special task force in an effort to identify the source of the outbreak.
Experts here have said it is only a matter of time before the highly infectious bacteria arrives in Ireland.
The proprietor of a German restaurant where a killer E coli food bug may have struck said today he was devastated to hear many of his guests were infected by the rare virulent bacteria.
'It was like a blow to the head when I heard the news,' Joachim Berger said in an interview in the kitchen of his restaurant in Luebeck, 60km northeast of the outbreak's epicentre in the northern port city of Hamburg.
'We had everyone here tested and everything was disinfected. I paid for the tests myself because safety is important for our guests and employees,' he said.
Authorities in Germany have yet to pin down the source of the pathogen, which has killed at least 19 people in Europe and made more than 1,700 ill in 12 countries - all of whom had been travelling in northern Germany.
But the Luebecker Nachrichten newspaper reported scientists had identified the local restaurant as a possible spot where the bug was passed on after one person died and 17 others fell sick, including a group of tax officials as well as Danish tourists and a child from southern Germany on a separate family outing.
The World Health Organisation has said the strain was a rare one, seen in humans before, but never in this kind of outbreak.
