Changing trends in β-hemolytic streptococcal bacteremia in Manitoba, Canada: 2007-2012.
OBJECTIVE
European surveillance studies have reported an increasing incidence of β-hemolytic group G streptococcal bacteremia, but no studies have evaluated trends in β-hemolytic streptococcal bacteremia in North America.


METHODS
We reviewed bacteremic episodes and positive throat swab cultures from two tertiary care centers in Manitoba, Canada, from January 2007 to December 2012.


RESULTS
During the study period, 19 864 bacteremic episodes, and 9948 positive throat swabs were identified. There were 1025 (5.16%) bacteremic episodes attributable to β-hemolytic streptococci: 425 (2.03%), 339 (1.71%), 62 (0.31%), and 199 (0.95%) to β-hemolytic groups A, B, C, and G streptococci, respectively. From 2007 to 2012, there were significant increases in the proportion of bacteremia attributable to β-hemolytic streptococci in general (6.32% vs. 4.02%; p<0.0001; linear trend test, p<0.0001), and to groups G (1.49% vs. 0.43%; p<0.0001; linear trend test, p<0.0001) and C (0.58% vs. 0.13%; p=0.0068; linear trend test, p=0.0105) β-hemolytic streptococci in particular. Bacteremia attributable to groups A and B β-hemolytic streptococci and Streptococcus pneumoniae were unchanged. There were no changes in the distribution of β-hemolytic streptococcal groups among throat swabs.


CONCLUSIONS
Bacteremia attributable to β-hemolytic groups G and C streptococci increased in Manitoba, Canada. Further study of the factors underlying these changes is required.
Departments of Medical Microbiology and Infectious Diseases, University of Manitoba, Room 543 Basic Medical Sciences Building, 745 Bannatyne Avenue, Winnipeg, MB, R3E 0J9, Canada; Department of Internal Medicine, University of Manitoba, Winnipeg, Manitoba, Canada. Electronic address: ilan.steven.schwartz@gmail.com.
Ilan Steven
IS
Schwartz
Departments of Medical Microbiology and Infectious Diseases, University of Manitoba, Room 543 Basic Medical Sciences Building, 745 Bannatyne Avenue, Winnipeg, MB, R3E 0J9, Canada; Department of Internal Medicine, University of Manitoba, Winnipeg, Manitoba, Canada.
Yoav
Y
Keynan
Departments of Medical Microbiology and Infectious Diseases, University of Manitoba, Room 543 Basic Medical Sciences Building, 745 Bannatyne Avenue, Winnipeg, MB, R3E 0J9, Canada; Diagnostic Services Manitoba, Winnipeg, Manitoba, Canada.
Matthew W
MW
Gilmour
University of Manitoba, George and Fay Yee Center for Healthcare Innovation, Winnipeg, Manitoba, Canada.
Brenden
B
Dufault
Departments of Medical Microbiology and Infectious Diseases, University of Manitoba, Room 543 Basic Medical Sciences Building, 745 Bannatyne Avenue, Winnipeg, MB, R3E 0J9, Canada; Diagnostic Services Manitoba, Winnipeg, Manitoba, Canada.
Philippe
P
Lagacé-Wiens
D016470:Bacteremia / Q000453:epidemiology* / Q000382:microbiology; D006801:Humans; D008350:Manitoba / Q000453:epidemiology; D013290:Streptococcal Infections / Q000453:epidemiology* / Q000382:microbiology; D013291:Streptococcus / Q000302:isolation & purification; D013296:Streptococcus pneumoniae / Q000302:isolation & purification
Bacteremia; Group C streptococci; Group G streptococci; Invasive streptococcal disease; β-Hemolytic streptococci