Danish authorities have reopened an investigation into a Salmonella outbreak after eight new infections surfaced since the summer holidays, bringing the total to 33 cases of the same type of Salmonella Enteritidis recorded since April 2026.

The Statens Serum Institut (SSI), the Danish Veterinary, Food, Agriculture and Fisheries Agency, and the National Food Institute had linked patients to a shared meal program at several schools in Sjælland before the summer break. The same meal service connects the eight cases recorded since the holidays ended.

SSI is running whole genome sequencing on patient isolates and conducting interviews to identify a possible source of infection. Initial interviews with patients or their parents showed that everyone who fell ill had received meals from the same provider at several different schools in Sjælland. At the time, investigators could not pinpoint a specific source, but the probe resumed after the recent cases matched the same meal service.

The affected group includes 17 males and 16 females. Patients are mainly children aged 3 to 15, though six adults aged 21 to 63 have also fallen sick.

Whole genome sequencing shows all isolates belong to sequence type 11 and are very closely genetically related, meaning a common source of infection is likely. Investigators have not yet named the meal provider, and no recall or enforcement action has been announced.

Second Salmonella Outbreak Under Investigation

Officials are also still searching for the source of a separate Salmonella outbreak.

SSI has recorded 33 cases of Salmonella Typhimurium between Aug. 4 and 27. Those affected include 12 men and 21 women, ranging from 6 to 83 years old, with a median age of 45. The regional distribution: 11 cases in Syddanmark, 10 in Midtjylland, seven in Nordjylland, three in Sjælland, and two in Hovedstaden.

Whole genome sequencing of patient samples shows the Typhimurium isolates are sequence type 19 and closely genetically related, again pointing to a single common source that investigators have yet to identify.

The reopened Enteritidis investigation puts renewed scrutiny on the school meal provider at the center of the case, and SSI's sequencing and interview work on both outbreaks is expected to narrow the source in the coming weeks.