Non-typhoid salmonellosis is a gastrointestinal infection characterised by diarrhoea, nausea and occasionally vomiting and fever. In 2017, 20 confirmed salmonellosis cases per 100,000 population were reported in the European Union (EU), making it the second most commonly reported food-borne infection . In Norway, it is mandatory to report all cases of salmonellosis to the Norwegian Surveillance System for Communicable Diseases (MSIS), and the medical microbiology laboratories submit Salmonella isolates to the National Reference Laboratory for Enteropathogenic Bacteria (NRL) at the Norwegian Institute of Public Health (NIPH) for confirmation and molecular epidemiological surveillance by whole genome sequencing (WGS). The incidence rate was 18 per 100,000 inhabitants in 2018
The majority of cases are travel-related, as Norway has few known domestic reservoirs. The dominating serotypes detected are Salmonella Typhimurium and Salmonella Enteritidis. Outbreaks involving different serovars of Salmonella are observed irregularly in Norway, with four national outbreaks reported in 2018.
On Tuesday 12 February 2019, the NRL identified a cluster of four S. Agbeni isolates, identical by WGS. Previously, this rare serotype of Salmonella had only been reported from a few sporadic cases in Norway and from a few outbreaks in the United States (US) and Canada. The cases resided in different municipalities in Norway. The following week, three more cases were detected. The initial interviews indicated a dried fruit mix product as the possible source of the outbreak. The NIPH initiated an outbreak investigation in collaboration with the Norwegian Food Safety Authority (NFSA) and the Norwegian Veterinary Institute (NVI) to identify the source of the outbreak and implement control measures.
This article describes the outbreak investigation and public health measures, and the finding that consumption of a ready-to-eat snack product of dried exotic fruits caused the outbreak of S. Agbeni in Norway.