At least 86 people have now been admitted to hospital as a result of an E coli outbreak linked to lettuce, health officials have said. A further 45 cases of E coli infection have been confirmed since 18 June, bringing the number of confirmed cases across the UK to 256. According to the UK Health Security Agency (UKHSA), those affected had developed symptoms before 31 May. The UKHSA said: “Although the rate of cases has now slowed, we expect the figure to rise as NHS laboratories refer specimens to UKHSA for genomic sequencing, which can link cases to this outbreak strain.” Food manufacturers have recalled sandwiches, wraps and salads sold in major supermarkets and retail chains over fears that they are linked to the outbreak. The Food Standards Agency (FSA) has said lettuce is thought to be the likely source of the outbreak. All the recorded cases involve Shiga toxin-producing E coli O145 (Stec). Darren Whitby, head of incidents at the FSA, said: “Several sandwich manufacturers have now taken precautionary action to withdraw and recall various sandwiches, wraps, subs and rolls, as food chain and epidemiological links have enabled us to narrow down a wide range of foods consumed to a small number of salad leaves that have been used in these products. “This remains a complex investigation and we continue to work at pace with the relevant businesses and local authorities to ensure necessary steps are being taken to protect consumers. “Although we are confident in the source of the outbreak being linked to a small number of salad leaves, which we identified early on through extensive food chain analysis, work continues to identify the root cause of the outbreak with the growers, suppliers and manufacturers so that actions can be taken to prevent a reoccurrence. “We will remain vigilant until the root cause of the outbreak is confirmed and we are keeping an open mind about possible causes of the outbreak.” E coli is a vast group of bacteria, some strains of which produce toxins that can make people severely ill. Symptoms include bloody diarrhoea, stomach cramps and a high fever. Further complications could include thrombotic thrombocytopenic purpura, which is when blood clots form throughout the body as a result of the illness. Some patients may also develop hemolytic uremic syndrome, which is linked to kidney failure and can cause life-threatening complications. Stec is often transmitted by eating contaminated food, but can also be spread by close contact with an infected person, as well as direct contact with an infected animal or its territory. People are advised to call NHS 111 or contact their GP surgery if they are worried about a baby under 12 months, if a child stops breast or bottle feeding while they are ill, if a child under five has signs of dehydration, such as fewer wet nappies, or if older children or adults still have signs of dehydration after using oral rehydration sachets.