The multidisciplinary outbreak control team (OCT) included representatives from the Chief Epidemiologist, the local Health Authorities, the Reykjavik Health Authorities, the Icelandic Food and Veterinary Authority, the Microbiology Department of Landspitali University Hospital, and district/regional Epidemiologists.

This Salmonella Typhimurium outbreak was first identified at the end of January 2024. Initially, the event appeared to be confined to preschool children in Húsavík, but subsequently cases were detected in other regions and among older individuals. Over a nearly five-month period, from January to May, a total of 17 cases across a wide age range were diagnosed with the same type of S. Typhimurium.

Salmonella Typhimurium was later identified in samples taken from domestic chickens at slaughter. Results from whole genome sequencing (WGS) later confirmed that the Salmonella typhimurium strains isolated from the infected individuals and the chicken were clonally related. It is therefore likely that the chicken meat was the source of the Salmonella infections. This outbreak investigation highlighted the importance of WGS in tracing the source of foodborne infections.

No clonally related Salmonella Typhimurium strains have been identified in other EU/EEA countries. The European Centre for Disease Prevention and Control (ECDC) monitors outbreaks in EU/EEA countries in collaboration with the European Food Safety Authority (EFSA).

The main symptoms of Salmonella infection are diarrhea, nausea and vomiting, abdominal pain, and fever. In most cases, the illness resolves within a few days. Antibiotic treatment is usually unnecessary but in some cases hospitalization is recommended to treat dehydration.

Salmonella is a bacterium with over 2,000 serotypes. S. Enteritidis and S. Typhimurium are the most common serotypes in Iceland. The primary route of transmission is contaminated food. The largest outbreaks of Salmonella in Iceland in recent decades occurred in 1996, caused by S. Enteritidis in cream buns, and in 2000, when S. Typhimurium was transmitted via iceberg lettuce.

Chief Epidemiologist

See:

• Report on Salmonella Typhimurium Outbreak (Icelandic). Published December 2024