A dried fruit mix linked to an outbreak of Salmonella in Norway contained products from South East Asia and Africa, according to researchers.
From the end of 2018 to mid-March 2019, 56 people fell ill and 21 were hospitalized but no deaths were recorded.
“The outbreak was characterized by an unusual, severe clinical presentation with systemic infections seen in seven, urinary tract infections in 10 and hospitalization in 21 of the 56 cases,” said researchers in the journal Eurosurveillance.
The mix contained fruit from different suppliers: cubed pineapple and papaya from Thailand, sultanas from Turkey, sliced coconut from Ghana and banana chips from the Philippines. It was packed at a factory in Italy in October 2018 and sent to Norway as a ready-to-eat product. In total, 4,032 bags at 400-grams each of the mix were exported to the Norwegian distributor and distributed to grocery stores and supermarkets.
The 33 women and 23 men affected by Salmonella Agbeni ranged in age from 2 to 91 years old. The majority were women above the age of 40. Those sick lived in 13 of the 18 counties in Norway. One person had a dual infection with Salmonella Wagenia and Salmonella Agbeni.
Patients mostly reported nausea, vomiting, abdominal pain, diarrhea, fever and joint pain but nine developed urinary tract infections (UTIs). Salmonella Agbeni was isolated from urine in 10 cases and from blood culture in seven, of which one had a UTI in addition to bacteraemia.
Investigators said observed clinical symptoms and rate of hospitalization could be explained by properties of the Salmonella serotype involved, or the fact that women above 40 are more likely to eat dried fruits than other age groups.
Patient interviews revealed 19 out of 20 had eaten different mixes of nuts, dried fruits and raisins. Other common items were spices, especially oregano for 16 people, and chicken products in 15 cases.
In a case-control study, consumption of dried banana and dried mixed fruit were strongly associated with illness. Other items linked to illness were dried papaya, dried apricot and dried pineapple.
Based on information from data sources including an electronic questionnaire and grocery store receipts, scientists confirmed 45 out of 56 patients had consumed the fruit mix.
Not clear where contamination occurred
Salmonella Agbeni was detected in all nine opened and one intact bag of “Dryss på – husk! eksotisk miks” that were tested. Another serovar, Salmonella Gamaba, was found from two intact packages.
The Italian company had previously taken 17 samples of the products but all microbiological analyses were negative for Salmonella spp. Testing of papaya, pineapple and banana chips by suppliers was negative. Italian food safety authorities inspected the facility and took five samples of sliced coconut which were negative for Salmonella spp.
Findings suggest the mix could have been contaminated with three different serotypes of Salmonella. Researchers said as all testing of the raw materials for the mix were negative, it is not known where in the production process contamination occurred.
“The complexity of the origin of the fruit mix and the finding of three different serovars of Salmonella highlight the need for strict hygiene measures when producing such ready-to-eat products,” they said.
The five raw materials used for the product were also mixed with other ingredients in 331 lots of 66 other products that were distributed from March 2018 in six European countries. Romania received the exact same mix as Norway but no other infections were reported.
The mix was recalled from the market in early March 2019 by the Norwegian distributor, Bama Gruppen. It had been on sale in supermarkets and grocery stores across Norway since mid-November 2018. Five other dried mix products that contained some of the ingredients from the same batch of raw materials used in the contaminated batch were also recalled but testing found they were negative for Salmonella.
Researchers said the outbreak highlights dried fruits as a risk product for foodborne infections, which is of particular concern in ready-to-eat products. Additional investigations are needed to estimate the risk of such products for pathogens.
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