The United Kingdom was hit by two outbreaks linked to melon in 2021, according to a recently released study. It was already known that the country was part of a multi-country Salmonella Braenderup outbreak, caused by melons from Honduras. However, there was another outbreak due to E. coli O157 which was also linked to imported melons, according to a study published in the Journal of Food Protection.
In July and August 2021, there were 17 cases of Shiga toxin-producing E. coli (STEC) O157:H7 in the UK. Reviewing STEC surveillance questionnaire data and analysis of responses from a modified hypothesis-generating questionnaire, implicated eating pre-cut watermelon from a retailer sourced from Europe as the vehicle of infection.
Watermelons came from three businesses in Spain. Melon was cut at a manufacturing facility in England and had a shelf life of five to six days. No whole or pre-cut watermelon samples in production in the days prior to symptom onset in cases were available for testing.
Authorities in Honduras did an onsite inspection of the growing farm in June 2021. A risk management plan was developed. There had been heavy rain for three days during the harvest. Salmonella Braenderup matching the outbreak strain was found on the surface of a washing tank in one of the Honduran facilities where Galia melons were packed.
“A variety of sources of contamination were possible; the most likely being that unusually high rainfall in Honduras during the harvest period resulted in sewage overflow and run-off contaminated the water used to irrigate the melon crops,” said scientists.
Postharvest contamination from an infected handler or cross-contamination from other products during the transportation process could also have occurred.
