Has the German outbreak peaked? It is too early to say but indications are that the rate of increase may be slowing.

Hospitals are seeing fewer new infections each day, according to Reinhard Brunkhorst, a kidney specialist in Hamburg and the president of the German Nephrology Society. "There is no reason for hysteria, because it's not spreading and it's not increasing – it's decreasing," he said, adding "it may be less, but it's not over yet".

The incubation period for severe illness linked with E. coli is typically three to four days. Salad vegetables, the suspected source, have a shelf-life of a few days so if a single batch is contaminated, the outbreak could peak rapidly and fade away. The World Health Organisation said it could not say whether this particular strain of E.coli was here to stay. Existing rapid testing kits for E.coli don't currently detect the new strain, which until recently had only been found in isolated instances and not large-scale outbreaks.