E. coli O157:H7 is a bacterium which is much more likely to produce complications in young children than adult patients, says Helen Puttick of The Herald.

For some patients, the toxins produced by the strain overwhelm the body and the organs fail. Infants can also suffer severe brain damage as a result of minor strokes, potentially leading to paralysis. But such cases are rare. Kidney failure is, however, more common, as is the case for children at a nursery in Fife.

Professor Hugh Pennington, the diseases specialist who led an expert group following the Wishaw E-coli O157 outbreak in 1996 and is now chairing an inquiry into the Welsh incident, says that “Many outbreaks of E. coli have been in nurseries. That is partly because kids are more susceptible to the bug and also because they are not yet trained in hygiene, so opportunity for person-to-person spread is much greater."

Environmental health officials have carried out swab tests inside the nursery to check for the presence of the germ, while the children, staff, and families of the three patients are being offered stool tests for the infection.

Letters are also being sent to the relevant homes, advising on thorough hand-washing to prevent further spread of the disease. However, as E. coli O157:H7 incubates for up to 14 days, even with these measures in place and the Careshare Group nursery shut, more people could yet fall ill.