The mother, who wishes to remain anonymous, said she had been left “very distressed” after finding out five weeks ago her child’s nursery was closing when a notification on the E.coli outbreak popped up on her phone.
There have been 56 confirmed cases of E.coli in several nurseries across the area.
Work is continuing behind the scenes to try to identify the source of the infection.
The East Lothian mother, whose son attends one of the three affected Pear Tree nurseries, said the situation had left her “isolated” after her boy tested positive for E.coli despite having no symptoms.
For more than a month, her son has been excluded from nursery and the mother said she has received no support, forcing her and her husband to take unpaid leave to cover childcare.
Her child can only return to nursery when he and his sister, who has been taken out of school as a result, test negative.
She said: “It’s a total shambles. I feel isolated and I feel our kids have been forgotten about. I’m worrying about this constantly and I’m not sleeping."
The mother is expecting further delays on her children’s education after being told it will take up to two weeks for test results to come back.
“There’s been absolutely no care and I feel they've put my daughter in harm’s way,” she said.
“I’m doing my best with home-schooling and looking after two kids, but I am also working from home and it’s just not possible to give her the same standard of education she would get at school.”
When the woman’s child can return, he has no funded place at a private nursery in the area.
Owners Bright Stars, which recently took over the privately-owned nurseries in Haddington, had its 1,140 funded nursery hours withdrawn as standards have fallen since their takeover.
The mother said this had created a significant issue and while she said she would apply for council nurseries, she felt there was “no guarantee” her child would get a place.
The council is urging parents to speak to their early years team as soon as possible so that colleagues can help them and allay some of their concerns.
An East Lothian Council spokesperson: “Our priority at this time is to support parents and carers who have enquiries regarding their next steps for early learning and childcare.”
Bright Stars has asked the council to reconsider the decision to pull the funded hours as they have paid £362,000 to cover the shortfall in funding for all eligible children until the Christmas break.
A Bright Stars Nurseries spokesperson said: “We believe this will offer sufficient time for the council to see what quality care and education means to us, giving them the confidence that the safety, care and education of the children they are funding is in the best possible hands.”