Following the last update on 5 July, PHE can now confirm that 151 cases of this strain of E. coli have been identified (figure correct as at 13 July 2016). This is 144 in England, 6 in Wales and 1 in Scotland, with the South West of England particularly affected. 62 of the cases are known to have received hospital care and sadly, 2 of the individuals with E.coli O157 infection have died.
Dr Isabel Oliver, director of PHE’s field epidemiology service, said:
PHE has been working to establish the cause of the outbreak and has identified that several of the affected individuals ate mixed salad leaves including rocket leaves prior to becoming unwell. Currently, the source of the outbreak is not confirmed and remains under investigation; we are not ruling out other food items as a potential source.
PHE is using various approaches including whole genome sequencing (WGS) technologies to test samples from those affected. WGS technologies are at the forefront of improving the diagnosis of infectious diseases and this testing has indicated that the strain involved is likely to be an imported strain, possibly from the Mediterranean area.
PHE is also working closely with the Food Standards Agency to trace, sample and test salad products grown in the UK and other parts of Europe. All food sample results to date have been negative for E.coli O157, but it’s important to be aware that where food has been contaminated with E.coli O157, it is not always possible to identify the bacteria on food testing.
As an additional precautionary measure, we have advised a small number of wholesalers to cease adding some imported rocket leaves to their mixed salad products pending further investigations.
Dr Isabel Oliver, director of PHE’s field epidemiology service, said:
PHE has put in place heightened surveillance for this strain of E. coli and is carefully monitoring the reporting of cases across the entire country. To assist with this investigation to help us find the source, we have convened a national outbreak control team who will also ensure all necessary control measures are put in place.
Currently, the source of the outbreak is not confirmed and this remains under investigation. However, our preliminary investigations have indicated that several of the affected individuals ate salad items including rocket prior to becoming unwell. At this stage we are not ruling out other food items as a potential source.
We continue to stress the importance of good hand and food hygiene practices at all times. We urge people to remove any loose soil before storing vegetables and thoroughly wash all vegetables (including salads) that will be eaten raw unless they have been pre-prepared and are specifically labelled ‘ready to eat’. These measures may reduce the risk of infection from any E.coli contaminated vegetables, fruit and salad but will not eliminate any risk of infection completely. PHE is working alongside the Food Standards Agency and will provide any further necessary public health advice as investigations continue.
It’s also vital to wash hands thoroughly using soap and water after using the toilet, before and after handling food and after contact with any animals and pets, including farm animals. Small children should also be supervised when washing their hands.
