An investigation into the deadly Strep A infection has not been able to identify a single source of transmission.

The Mid Essex clinical commissioning group commissioned an independent report to address the outbreak of the Group A streptococcus (iGAS) which infected 39 individuals and claimed 15 lives.

Of those 15, one individual died at Colchester Hospital and twelve at Broomfield.

Investigators spoke to the families of the deceased and met healthcare staff and clinical leaders responsible for their care to determine the cause of the outbreak.

But a report was released which said the investigating team could not identify a single source of the transmission. It said the spread was likely to have occurred in a number of ways with no direct link to any individual.

Rachel Hearn, director of nursing at Mid Essex CCG said: “I would like to express our deepest sympathies to the families of those patients who passed away.

“We thank them for contributing to the investigation at such a difficult time.

“We commissioned this independent investigation to ensure that we could understand areas for improvement and take prompt action to reduce the risk of a similar outbreak happening again.

“The report details a number of recommendations and we have taken swift action along with our partners to ensure changes have been made quickly and safely.”

A total of 22 recommendations were made as a result of the investigation.

Of these more than a third have been fully implemented and the rest are on track to be completed by the end of the year.

Recommendations include a healthcare plan to respond effectively to an infection outbreak.

It also covers wound management, identifying clinical deterioration, antibiotic therapy and record keeping.

Chief Nurse at Provide Stephanie Dawe said: “We may never fully understand the route of transmission but there are clearly things we need to do differently.

“The healthcare system found this outbreak an extraordinary challenge and there was much learning taking place for our teams and organisation.”