An investigation into a Salmonella outbreak in Sweden has been restarted after more people fell sick. From August to October, 81 people from 18 regions contracted Salmonella Typhimurium with sequence type (ST) 36. Where information about the country of infection is available, all cases were infected in Sweden.
Folkhälsomyndigheten (the Public Health Agency of Sweden) reported that patients are infected with one of about 10 different but genetically related bacterial variants that have caused illness. Further cases after initial work I n September, an outbreak investigation was opened for people infected with a specific variant of Salmonella Typhimurium ST 36 . In August and September, 35 people from 11 different regions became ill.
Information about possible sources of infection was collected via interviews, questionnaires, and purchase receipts from cases, but this did not identify what food caused illnesses. Officials believed the source of infection was likely a food item with a limited shelf life that was no longer on the market. The investigation was closed but has now been restarted and broadened as several new variants of sequence type 36 have been identified.
Since Salmonella Typhimurium ST 36 is unusual in Sweden and because cases with isolates belonging to different variants of this type have been detected during the same period, officials believe that a common source of infection causes the outbreak. Patients range in age from less than 1 to 89, and the median is.