Investigation of Salmonella enteritidis outbreak in four kindergartens

In June 2018, in the city of Sofia, Bulgaria, 40 children from four different kindergartens suffered from salmonellosis caused by S. enteritidis. They were reported to have consumed food prepared and delivered by a private catering service. The patients had fever, diarrhea, and some had vomiting and abdominal pain. Sixteen of them were treated in hospital, and the other 24 received home treatment. Some of the outpatients received antibiotic treatment despite WHO recommendations. All 40 isolates were positive for O: D, H: gm and H: m, and were confirmed to be Salmonella enteritidis, respectively. Using conventional and molecular methods, such as serotyping, Multiplex-PCR and PFGE, it was confirmed that the strains were epidemiologically related. Based on molecular genetic methods, we established that the epidemic outbreak had a common origin: contaminated food delivered by a private catering service, which was consumed at all four kindergartens.