Watermelon found to be source of salmonella outbreak
- 2 February 2012
- From the section Health
A salmonella outbreak linked to watermelons has affected 35 people in the UK, health experts have revealed.
One person has died, although they had serious underlying health issues.
The Health Protection Agency (HPA) said three times the usual number of cases of Salmonella Newport infection for this time of year had been seen.
Cases of illness caused by the same strain have been seen in Ireland and Germany.
Over 200 cases of Salmonella Newport are reported in the UK each year.
Infection causes a similar illness to other forms of salmonella infection and symptoms include diarrhoea, vomiting, abdominal pain and fever.
The people affected in this outbreak, which began in early December, ranged in age from six months to 85 years.
Around 70% of cases were in women, and the East of England has had more cases than other regions.
Experts say there are two possible ways watermelons could have caused infection.
One is that the surface of the melons could have been contaminated with Salmonella bacteria which may have transferred on to the flesh of the melon during the cutting process.
The second is if the melons were stored or washed in contaminated water, the salmonella bacteria could have got into the flesh of the melon through the cut stem.
'Wash fruit and veg'
"Although it's too soon to say with certainty what the likely cause of infection is, early indications suggest that a number of people became unwell after eating watermelon," said Dr Bob Adak, head of the gastrointestinal diseases department at the HPA, which has been monitoring the outbreak in England, Wales and Northern Ireland.
"This has also been noted in the cases in Scotland and Germany although further investigation is ongoing."
He added: "It's important to remember the risk of becoming unwell after eating watermelon is very low. These cases only represent a very small proportion of total consumption.
"It is always advisable to wash fruits and vegetables - including watermelon - before consumption to reduce the risk of possible illness."
Dr Paul Wigley, at the University of Liverpool said: "Salmonella Newport is not an particularly unusual form.
"Fruit and vegetables are not the main source of infection which is usually meat or unpasteurised dairy products, but they can be contaminated with Salmonella in production or processing.
"There are examples of fruit and salad vegetables causing major salmonella outbreaks including salad onions, lettuce and peanuts. As Salmonella Newport is often associated with cattle or horses, contamination from animal manure used as fertiliser is a potential source. "
The HPA and the Food Standards Agency are currently investigating the source of this outbreak.
Salmonella Newport has been found in many different foods in previous UK outbreaks - the largest one was in 2004 and was associated with eating lettuce at restaurants and takeaways.