Table 1. Variants of invasive group A Streptococcus isolates from cases treated in semi-intensive or intensive care units and from fatal cases, Denmark, January 2018–February 2023 (n = 839).
| Variant | n | Cases in intensive care | Fatal cases | ||||||
|---|---|---|---|---|---|---|---|---|---|
| n | % | p value | OR (95% CI) | n | % | p value | OR (95% CI) | ||
| M1DK (ST28/EMM-1) | 62 | 24 | 38.7 | 0.002 | 2.38 (1.32–4.2) | 10 | 16.1 | 0.9 | 1.08 (0.48–2.24) |
| M1UK (ST28/EMM-1) | 119 | 38 | 31.9 | 0.009 | 1.8 (1.14–2.8) | 16 | 13.4 | 0.7 | 0.85 (0.45–1.52) |
| M1global (ST28/EMM-1) | 70 | 23 | 32.9 | 0.04 | 1.8 (1.01–3.13) | 11 | 15.7 | 0.9 | 1.05 (0.48–2.09) |
| ST36/EMM-12 | 111 | 24 | 21.6 | 0.9 | 0.96 (0.56–1.58) | 18 | 16.2 | 0.8 | 1.1 (0.6–1.92) |
| ST101/EMM-89 | 69 | 12 | 17.4 | 0.4 | 0.72 (0.34–1.39) | 10 | 14.5 | 1 | 0.95 (0.42–1.93) |
| ST52/EMM-28 | 62 | 12 | 19.4 | 0.6 | 0.83 (0.39–1.62) | 6 | 9.7 | 0.3 | 0.58 (0.2–1.39) |
| ST44/EMM-66 | 35 | 6 | 17.1 | 0.5 | 0.71 (0.24–1.78) | 5 | 14.3 | 1 | 0.93 (0.28–2.49) |
| ST39/EMM-4 | 34 | 1 | 2.9 | 0.003 | 0.1 (0–0.61) | 2 | 5.9 | 0.2 | 0.34 (0.04–1.36) |
| ST62/EMM-87 | 21 | 2 | 9.5 | 0.2 | 0.36 (0.04–1.52) | 2 | 9.5 | 0.8 | 0.58 (0.07–2.47) |
| Other ST | 256 | 45 | 17.6 | 0.03 | 0.66 (0.45–0.97) | 47 | 18.4 | 0.09 | 1.41 (0.93–2.13) |
CI: confidence interval; EMM: the M protein; GAS: group A Streptococcus; iGAS: invasive group A Streptococcus; nGAS: non-invasive group A Streptococcus; OR: Odds ratio; ST: sequence type.
p values and ORs are based on Fisher’s exact test, comparing the distribution for one variant to the combined distribution of other variants.