serovars associated with bacteremia in Canada, 2006-2019.

Background: Members of the bacterial genus cause salmonellosis, a disease with a spectrum of clinical presentations from a self-limiting gastroenteritis to more severe bacteremia, organ failure and sepsis. The genus consists of over 2,600 serological variants (serovars). Important differences in the pathogenesis of serovars have been noted.

Objective: The purpose of this study was to determine which serovars were more likely to be associated with bacteremia in Canada.

Methods: Information on the total number of infections and blood isolations reported to the National Enteric Surveillance Program (NESP) from 2006 to 2019 was extracted for each serovar. The risk (proportion) and likelihood (odds) of bacteremia were calculated for all serovars.

Results: Of the 96,082 cases reported to the NESP during the 14-year study period, 4.4% (95% CI: 4.3%-4.6%) were bacteremic. Twenty nontyphoidal (NTS) serovars were associated with lower rates of bacteremia compared to all NTS serovars, and 19 NTS serovars were identified as having higher rates. Heidelberg, Oranienburg, Schwarzengrund, Virchow, Panama and Poona among the top 25 most commonly reported serovars in Canada during the study period.

Conclusion: The identification of serovars associated with bacteremia in Canada is a first step towards understanding differences in pathogenesis and disease presentation.