Table 2.
Clinical Features of Invasive Group A Streptococcal Disease due to emm74 and emm1 in Residents of Metropolitan Toronto and Peel Region, Canada, 12/2015–5/2017
| No. (%) of Isolates | P Value | Odds Ratio (95% CL) | ||
|---|---|---|---|---|
| emm74 (N = 58) | emm1 (N = 54) | |||
| Age group, y | ||||
| 0–18 | 0 | 11 (20) | .0002 | |
| 19–40 | 13 (22) | 11 (20) | .8 | |
| 41–60 | 22 (38) | 9 (17) | .02 | |
| ≥61 | 23 (40) | 23 (43) | .9 | |
| Male sex | 38 (66) | 30 (56) | .3 | |
| Risk factor for infection | ||||
| Alcohol abuse | 12 (21) | 2 (3.7) | .009 | 6.8 (1.4–32) |
| Homeless | 17 (29) | 0 (0) | <.0001 | N/A |
| IV drug user | 13 (22) | 1 (1.9) | .001 | 15 (1.9–122) |
| Underlying chronic disease | ||||
| Any | 53 (91) | 40 (74) | .02 | 3.7 (1.2–11) |
| Cardiac disease | 9 (16) | 10 (19) | .8 | |
| Diabetes mellitus | 11 (19) | 6 (11) | .3 | |
| Malignancy (last 2 y) | 5 (8.6) | 5 (9.3) | 1.0 | |
| HIV infection | 3 (5.2) | 0 (0) | .2 | |
| Clinical presentationa | ||||
| Soft tissue infection (all) | 31 (53) | 19 (35) | .06 | |
| Non-necrotizing fasciitis | 29 (50) | 14 (26) | .01 | 2.9 (1.3–6.3) |
| Necrotizing fasciitis | 2 (3.4) | 5 (9.3) | .3 | |
| Respiratory tract infection | 4 (6.9) | 22 (41) | .0001 | 0.11 (0.03–0.34) |
| Bacteremia without focus | 9 (16) | 9 (17) | 1.0 | |
| Arthritis | 10 (17) | 7 (13) | .6 | |
| Otherb | 6 (10) | 5 (9.3) | 1.0 | |
| Streptococcal toxic shock syndrome | 8 (14) | 12 (22) | .3 | |
| Outcomes | ||||
| ICU admission | 17 (29) | 26 (48) | .05 | 0.45 (0.20–0.97) |
| Death | 5 (8.6) | 6 (11) | .8 | |
Abbreviations: CL, confidence limit; ICU, intensive care unit; IV, intravenous.
aTotals are greater than the number of cases because patients may present with more than 1 site of infection.
bOther includes 4 cases of osteomyelitis (2 each emm74 and emm1); 2 of peritonitis (1 each emm74 and emm1), and 1 case each of endocarditis (emm74), mastoiditis/meningitis (emm1), peripartum infection (emm1), other gynecologic infection (emm74), and urinary tract infection (emm74).