A stark message on the local authority’s website reads: "Risk of infection - There is an outbreak of E.coli O157 in Sutton Park."
The message continues: "Infection can lead to very serious illness. It is linked to contact with animals and animal poo. You can pick up this bug on your hands and accidentally transfer it to your mouth. Young children are particularly at risk."
Sutton park covers 970ha of land and is one of the largest urban parks in Europe, attracting over two million visitors a year.
The notice urges several precautions such as keeping kids aged 10 or younger away from the park, to avoid eating or playing in areas where there are animals or animal faeces and to wash hands as soon as possible after touching fences or contaminated clothes.
Health chiefs swung into action after eight people fell ill including six youngsters. One child, who fell seriously ill, is expected to make a full recovery. However the Health Protection Unit in Birmingham said it was unable to ban children from the park.
Birmingham City Council’s head of parks Darren Share said: "We are working closely with the Health Protection Agency to control this outbreak and we have already taken a number of measures.
"But as the infection can be particularly serious for young children we feel it is appropriate at this stage to warn parents and families of the potential risks. There are signs throughout the park informing visitors of the outbreak and the steps they can take to protect themselves."
E. coli O157 is a germ that can cause infection of the bowel. It is usually spread by contact with animals and symptoms include diarrhoea, abdominal pain, raised temperature and shivering. Spread of infection can be prevented by thorough hand washing.