A MYSTERIOUS E. coli outbreak that swept across the UK last year left one dead and dozens ‘severely ill’, as officials raced to find the source of the outbreak.
Now, investigations have confirmed minced beef as the probable cause.
GettyAn E. Coli outbreak sickened 27 and killed one Brit in summer 2023[/caption]
GettyResearchers said minced meat was a probable source of the outbreak[/caption]
AlamyBut they weren’t able to trace it back to a particular supplier or source[/caption]
The spate of severe gastrointestinal illnesses was first detected by the UK Health Security Agency (UKHSA) surveillance systems in June 2023.
Health officials were were able to determine that the outbreak was being cause by Shiga toxin-producing Escherichia coli (STEC) O183:H18, a rare strain of E. coli that leaves sufferers with bloody diarrhoea, as well as tummy pain, fever and vomiting.
But how Brits were being contaminated with the bacteria in the first place has remained a mystery.
At the time, officials suggested hard cheese, strawberries cucumbers, peppers and watermelon could be the source.
As the STEC strain causing the illnesses is rarely seen in the UK and patients seemed to be experiencing severeoutcomes, and an incident management team meeting was convened.
A report published in the journal Microbial Genomics confirmed that sufferers likely picked the illness up from eating beef burgers or minced beef.
A PROCESS OF ELIMINATION
Between May and July 2023, there were 27 confirmed cases linked to the STEC outbreak and one probable one.
One person developed hemolytic uremic syndrome (HUS) after their bout of E. coli – this is a rare kidney condition can cause damage to red blood cells and blood vessels and result in kidney failure.
Another person passed away in connection to the outbreak, though their death certificate doesn’t state whether STEC caused or contributed to their death.
Sufferers were aged between six months and 74 years – though almost half (42 per cent) of the cases occurred in children aged nine and under.
Cases were distributed across the UK, with 21 (81 per cent) reported in England, three in Northern Ireland, two in Scotland and two in Wales.
Patients infected with STEC can be struck by a wide array of symptoms, ranging from mild diarrhoea to severe, blood-stained diarrhoea, abdominal pain, fever and vomiting.
Of the 24 patients study authors were able to gather information on, 17 said they’d been struck with bloody diarrhoea and eight of them went to hospital.
Researchers also gathered data on what half the patients ate in the lead-up to their illness, with 68 per cent saying they’d consumed cooked chicken.
Meanwhile, 55 per cent said they’d eaten cooked beef, 68 per cent said pasteurised milk and 77 per cent said they’d eaten hard cheeses.
Ten of the patients later completed questionnaires to collect a detailed food history two weeks before the onset of symptoms.
Commonly reported food items were strawberries (70 per cent), pasteurised milk (80 per cent), hard cheeses (100 per cent), chicken (100 per cent), and beef (100 per cent).
All the commonly reported foods were investigated, but it was deemed unlikely that chicken and pasteurised dairy products could have transmitted STEC infections, as no previous STEC outbreaks linked to these food items had been previously recorded in the UK.
“In contrast, cattle are well established as an animal reservoir for STEC, and undercooked beef meat products, particularly beef burgers and beef mince, are often implicated in food-borne outbreaks of STEC,” researchers wrote.
“All ten cases that completed a questionnaire reported consumption of either beef burgers, beef mince cooked at home or other beef mince products,” they added.
Recent outbreaks of STEC in the UK have been linked to person-to-person transmission in nursery schools, contact with animals at petting farms, while food-borne outbreaks have been linked to unpasteurised dairy products and fresh produce, study authors noted.
OUTBREAK ‘LIKELY MORE WIDESPREAD’
The Food Standards Agency (FSA) launched a food chain investigation examining common beef suppliers and processors, in order to identify where the contaminated beef had come from.
“However, the complexity of the beef industry supply lines hampered progress,” researchers said.
“Food chain investigations were de-escalated once the outbreak was over, and the source of the contaminated food was never confirmed.”
They warned that “the outbreak is likely to be more widespread than described here” as many laboratories in England don’t perform the required tests to identify the rare E. Coli strain and so wouldn’t have been able to diagnose it.
E. coli O183 is an extremely rare serotype, with only 15 cases in the UK since 2016.
Researchers suggested that this STEC serotype could have been imported into the UK or it might be a domestic strain of E. coli that has recently acquired elements from an external source.
“Whether or not STEC O183:H18 will emerge as an on-going threat to public health remains to be seen,” they added.
What are the symptoms of STEC?
Shiga toxin-producing Escherichia coli can cause gastrointestinal illness that can become severe.
The most common type of STEC in the UK is O157, according to a 2017 report by Public Health England.
Some people who are exposed to STEC do not become ill. Others develop stomach cramps and bloody diarrhoea.
Symptoms can also include vomiting, fever, and chills.
In severe cases, the infection can damage organs, such as the kidneys.
Symptoms can appear anywhere from one to ten days after exposure, but usually appear around three to four days after exposure.
Most of those affected by the bug will get better without treatment within a week.Sufferers are advised to drink plenty of fluids to stay hydrated.
Are you at risk of getting it?
People can become infected by:
Eating contaminated food
Contact with infected animals either directly or through inadvertent contact with animal faeces, for example at farms, petting farms and campsites
Contact with other people who have the illness (through inadequate hand hygiene after using the toilet, before food handling – particularly in households, nurseries and infant schools, or both
Drinking water from inadequately treated water supplies
Swimming or playing in contaminated water such as ponds or streams
STEC are very infectious because very few bacteria are needed to cause illness.
This means that disease can spread easily within families and in other settings such as day nurseries, primary schools, nursing homes and hospitals where there are young children and others who might have difficulty in keeping clean.
How can you protect yourself from STEC?
A STEC infection can be prevented by taking the following precautions:
Cook all minced meat products (burgers, meatloaf, meat balls) thoroughly, until the colour is the same all the way through, and no blood runs from them
Ensure refrigerators are working correctly – bacteria grow more quickly at temperatures over 4oC
Only leave cooked foods, meat and dairy products out at room temperature for a short time
Store uncooked meats below cooked meats and salad vegetables to avoid dripping juices onto ready to eat food
Store uncooked and cooked meats on different plates, avoid all contact between raw and cooked meats
Thoroughly wash all salad vegetables and do not prepare them with utensils that have also been used for raw meat
Children and the elderly who are particularly susceptible to the severe effects of STEC should avoid eating or drinking unpasteurised dairy products
People who have been ill should not prepare food for others for at least 48 hours after they have recovered
Boil any drinking water if you are unsure of it’s source
Do not swim in water that you think may be contaminated by cattle and sheep in nearby fields
Wash your hands thoroughly after using the toilet (or helping others including changing nappies), handling raw meat, before meals and after contact with animals
Source: PHE