Abstract
We report a multistate Salmonella enterica serovar Heidelberg outbreak in Australia during 2018–2019. Laboratory investigation of cases reported across 5 jurisdictions over a 7-month period could not identify a source of infection but detected indicators of severity and invasiveness. The hospitalization rate of 36% suggested a moderately severe clinical picture.
Salmonella enterica serovar Heidelberg is a frequently identified serotype among infections in humans in North America, East Africa, and Asia but is uncommon in Australia. An average of 37 cases of Salmonella Heidelberg were notified in Australia annually in 2009–2017, predominantly overseas acquired (1). Six outbreaks have been reported nationally since 1995; 1 outbreak in 1996 had >500 cases, but most have <7 cases (R. Bell, pers. comm. [email], 2020 Jun 16). We report a national outbreak of Salmonella Heidelberg infection across 5 jurisdictions over 7 months.
We report a national outbreak investigation of a locally uncommon S. enterica serovar of unknown origins in Australia. Although Salmonella Heidelberg outbreaks are relatively uncommon in Australia, given this outbreak’s comparatively high hospitalization rate and the presence of saf fimbrial genes in the implicated strain, future cases warrant prompt investigation to assess severity and invasiveness. A platform for real-time exchange of sequence data in Australia and use of routine WGS for salmonellosis cases, including comparison with local and international strain data, may enable more timely detection of outbreaks.
FoodWorld 