Water parasite found in pre-washed vegetables

The cryptosporidium organism can cause illness in people and some animals

A waterborne disease has been discovered in pre-washed vegetables being sold in Kent.

Cryptosporidium, which can cause diarrhoea and sickness, was found in 17% of samples of pre-washed vegetables analysed by scientists at the University of Kent.

Anastasios Tsaousis, from the university’s School of Biosciences, who led the research, said: “The presence of cryptosporidium in pre-washed vegetables could mean revisiting the sanitation methods employed by suppliers along the chain of production.

“There is also a need for increased awareness among consumers on the adequate storage of vegetables and handwashing before eating.”

The pilot study was conducted between May and July 2023 on 36 pre-washed bags containing a variety of vegetables.

Dr Tsaousis said the 2023 study could not distinguish between "live and inert" cryptosporidium.

Cryptosporidium is a parasite that causes an infection affecting people and farm animals with symptoms such as diarrhoea, vomiting, stomach pains and fever.

Boiling water

It is usually found in lakes, streams, rivers and untreated drinking water.

Pre-washed and ready-to-eat vegetables undergo more thorough washing with water containing chlorine disinfectants compared to unpackaged vegetables.

But cryptosporidium particles have been found to be resistant to disinfection with chlorine and can only be reliably removed by boiling water or filtration, according to the research.

Dr Tsaousis said suppliers may need to consider improving hygiene measures during harvesting, processing, packaging, transportation and storage.

Cryptosporidium has most recently been identified for contaminating drinking water in areas of the UK.

Residents in Devon have been boiling their water for nearly a month due to an outbreak.

About 2,500 homes remain under a boil water notice after cryptosporidium was found in the water supply in Brixham on 15 May.