AN investigation as to how 31 people contracted a rare strain of E. coli that left some children with lifelong kidney damage has failed to find the source.

Public Heath England's investigation, which aimed to find the cause of the outbreak of Verocytotoxigenic Escherichia coli (VTEC) O55 which occurred in Dorset, was closed in March.

Further tests are being carried out on the rare strain - works which Public Health hope to be completed early next year.

Ten children were among those taken unwell between July 2014 and November 2015.

Dr Sarah Harrison, consultant in health protection at Public Health England south west, said: “Our colleagues in Public Health England worked closely with partners to try and identify a possible common source of infection, but the investigations did not identify a single common source. It is very good news that there have been no further cases of infection with this strain since the end of the outbreak in 2015, however we remain vigilant.

“In order to understand more about this strain of E.coli, a new test has been developed by scientists at the Animal and Plant Health Agency (APHA), using microscopic magnetic beads which detect E. coli O55. The test is in its final stage of Reactive Statement development and, once the work is complete, the test will be used in the event of an outbreak of E. coli O55, to investigate the source of the infection. It could also be used by APHA in studies to look at the incidence and prevalence of E. coli O55 in animals. We hope that the work will be completed in early 2017."