The multi-agency Incident Management Team (IMT) said there have been no new cases of the infection in more than 28 days, meaning that the outbreak has been concluded.
A total of 57 cases were identified and five nurseries in Musselburgh and Haddington were closed as a safety precaution during the outbreak of E-coli.
The IMT, which was formed to manage the outbreak response, thanked all of the affected families for helping to contain the outbreak and prevent further spread through the community.
Dr Graham Mackenzie, Consultant in Public Health Medicine and Chair of the IMT, said: “We are very grateful to families, nurseries, and other workplaces affected by this outbreak. Your collective action has helped to minimise the onward spread of this dangerous bug.”
Letters advising families about the conclusion of the outbreak and the most up to date information have also been issued.
Work is still continuing behind the scenes by the health care scientists in epidemiology and microbiology to try and identify the source of the infection.
The Health Protection Team is also working with and supporting some families through the clearance process, which is a normal part of an E. coli outbreak.
Dr Mackenzie reminded families of the need for ongoing good hand hygiene, especially as Scotland experiences an overall rise in the number of cases of E-coli.
He added: “This outbreak has highlighted the importance of careful handwashing, with soap and warm water, and drying hands thoroughly, before eating and after going to the toilet.
“It also reinforces the need to stay off nursery, school or work, while unwell. With most vomiting and diarrhoea illnesses it is important to stay off for 48 hours after symptoms have stopped. E. coli is different because of the seriousness of infection.
“The outbreak in Haddington and Musselburgh has coincided with a national rise in E. coli cases. It is important to remain vigilant.”