A Salmonella outbreak that sickened more than 130 people in Chile may have been caused after food was contaminated with a strain used to monitor testing performance.

The Salmonella Abony outbreak occurred from January to April 2024. Genomic evidence indicated that the outbreak strain was a clone of a reference strain, which is routinely used in microbiological quality control tests.

According to information published in the journal Emerging Infectious Diseases, two healthcare centers in Santiago diagnosed 134 salmonellosis cases from January to March: 29 at UC-Christus and 105 at Clínica Alemana. All isolates were submitted to Instituto de Salud Pública de Chile for serotyping.

Salmonella Abony was found in 56 of 97 cases with culture. Of these, 33 patients were male and 23 were female. Forty were under 18 years old, 17 required hospitalization, and 10 had bacteremia.

18 of 56 outbreak isolates were subjected to whole genome sequencing. The samples were from blood, urine, and feces.

Outbreak of rare Salmonella type

According to data from the Government of Chile, 287 Salmonella Abony isolates were collected between January and April from 12 of 16 administrative regions. Some isolates may have been obtained from the same patient. Infected people ranged in age from under 1 to 82 years old. More than 200 isolates came from Región Metropolitana, and 165 were obtained in February 2024.

However, scientists did not have addit...