Open Access Highly Accessed Research article

Incidence, risk factors, and outcomes of Fusobacterium species bacteremia

Kevin Afra1, Kevin Laupland123, Jenine Leal5, Tracie Lloyd4 and Daniel Gregson134*

Author Affiliations

1 Department of Medicine, University of Calgary, Calgary, Canada

2 Department of Critical Care, University of Calgary, Calgary, Canada

3 Department of Pathology and Laboratory Medicine, University of Calgary, Calgary, Canada

4 Calgary Laboratory Services, Section of Medical Microbiology, #9- 3535 Research Rd. NW, Calgary, Alberta, T2A 2K8, Canada

5 Infection Prevention & Control, Foothills Medical Centre, Calgary, Canada

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BMC Infectious Diseases 2013, 13:264  doi:10.1186/1471-2334-13-264

Published: 5 June 2013



Fusobacterium species (spp.) bacteremia is uncommon and has been associated with a variety of clinical presentations. We conducted a retrospective, population based study to determine the relative proportion of species in this genus causing bacteremia and the risk factors for infection and adverse clinical outcomes.


All cases of Fusobacterium spp. bacteremia detected at a regional microbiology laboratory serving outpatient and acute care for a population of approximately 1.3 million people over 11 years were identified from a computerized database. Clinical data on these cases was extracted from an administrative database and analyzed to determine underlying risk factors for and outcomes of infection.


There were 72 incident cases of Fusobacterium spp. bacteremia over the study period (0.55 cases/100,000 population per annum). F. nucleatum was the most frequent species (61%), followed by F. necrophorum (25%). F. necrophorum bacteremia occurred in a younger population without underlying comorbidities and was not associated with mortality. F. nucleatum bacteremia was found in an older population and was associated with underlying malignancy or receiving dialysis. Death occurred in approximately 10% of F. nucleatum cases but causality was not established in this study.


Fusobacterium spp. bacteremia in our community is uncommon and occurs in approximately 5.5 cases per million population per annum. F. necrophorum occurred in an otherwise young healthy population and was not associated with any mortality. F. nucleatum was found primarily in older patients with chronic medical conditions and was associated with a mortality of approximately 10%. Bacteremias from other Fusobacterium spp. were rare.

Bacteremia; Fusobacterium; Mortality; Incidence; Risk factors