Almost a fifth of pre-washed vegetables on supermarket shelves in the UK could contain a parasite found in contaminated faeces, a study suggests.
Scientists found traces of cryptosporidium, the same parasite responsible for an outbreak that affected over 100 people in Devon last month, causing severe gastric symptoms, in 17 per cent of supposedly ready-to-eat vegetables.
Experts behind the study would not reveal which supermarkets had the tainted veg as they instead wanted to raise awareness about the supply chain that leads to this contamination, rather than specific outlets.
But they told MailOnline the level of risk was likely to be the same across the sector and that all ‘pre-washed’ or ready-to-eat greens should be treated with suspicion.
Cryptosporidium is normally contracted via drinking water contaminated by infected human or animal faeces, like the outbreak in Devon earlier this year. However, you can also get it from food.
Experts from the University of Kent found in cryptosporidium in 17 per cent of supposedly ready-to-eat vegetables purchased from supermarkets
Cryptosporidium parasites are protected by a thick shell that allows them to survive even in chlorinated swimming pool water
This usually occurs when vegetables have been grown in infected manure and not been washed thoroughly enough or if a person infected with the parasite has been involved in food preparation.
In their study, experts from the University of Kent analysed 24 samples of pre-washed vegetables collected from four supermarkets in Canterbury in 2023.
Four of these (17 per cent) tested positive for traces of cryptosporidium.
While these vegetables had been washed with water containing disinfectants cryptosporidium is resistant to these and therefore can survive this process.
This is significant, as eating just a tiny amount of cryptosporidium, just 10 oocysts, the form the parasite takes to survive outside a host, is enough to make a person ill.
The experts behind the study were only able to detect ‘traces’ of the parasite, and could not confirm whether there were enough oocysts present to cause illness.
However Dr Anastasios Tsaousis, lead author of the study and an expert in parasites, told MailOnline there was likely to be some risk ifor all kinds of pre-washed vegetables.
‘Any product that is coming from the environment, e.g. soil and water exposure, will have the same risk,’ he said.
This in part due to such vegetables being processed in central facilities before being distributed across the nation.
He added that he would recommend all Brits wash such vegetables again themselves to reduce their risk of exposure.
Dr Tsaousis also said the team’s discovery suggested improvements need to be made in processing of these vegetables.
‘The presence of cryptosporidium in pre-washed vegetables could mean revisiting the sanitation methods employed by suppliers along the chain of production such as improved hygiene measures during harvesting, processing, packaging, transportation and storage,’ he said.
‘There is also a need for increased awareness among consumers on the adequate storage of vegetables and handwashing before eating.’
Suggested methods include ensuring all water used in vegetable supply chain preparations was thoroughly boiled before use, or using other sanitization methods such as using ozone for additional security.
The authors, who published their work in the journal Parasitology Research, said the presence of cryptosporidium in pre-washed vegetables was concerning given how people were increasing relying on these products as a healthy food option.
‘In recent years, ready-to-eat vegetables have become increasingly attractive to consumers by readily providing healthy, no-preparation-needed nutrition,’ they wrote.
They suggested that other research could examine how exactly vegetables are being contaminated further up the supply chain.
Medics technically call a cryptosporidium infection cryptosporidiosis.
Sufferers often have to endure these symptoms for two weeks before it is finally clear from their systems.
But some patients can experience longer bouts of illness for those people with weakened immune systems like cancer patients.
Victims can also experience periods of false hope where their symptoms clear for a few days, making them believe they are finally over the infection, only for it to return.
Most people with cryptosporidiosis aren’t offered treatment and are instead told to drink plenty of fluids.
Patients with the infection are told to stay off work and school until they have been symptom-free for at least two days to avoid passing the bug on to others.
Food safety of products bought on supermarket shelves has come increasing focus after hundreds of Brits were struck down by a rare strain of E. Coli linked to contaminated salad leaves which led to a mass product recall.
Source: Mail Online
