Table 1.

Characteristics of invasive beta-haemolytic streptococci (BHS) and group A, B, C and G streptococci (GAS, GBS, GCS and GGS, respectively) in Denmark from 2005 to 2011

	GAS (n = 994)	GBS (n = 767)	GCS (n = 233)	GGS (n = 984)	All BHS (n = 2978)
Isolates from clinical material (%)
Blood	93.1	93.2	97.4	96.9	94.7
Cerebrospinal fluid	1.4	4.0	0.4	0.3	1.6
Other sterile material	5.5	2.7	2.2	2.9	3.7
Patient information, age (years)
Median age	63.2	62.2	68.7	71.2	66.2
Age interquartile rangea	42.3–75.2	35.1–75.9	58.0–79.0	60.5–81.7	50.3–78.6
Age range	0–99	0–98	0–100	0–100	0–100
Age group (years) related incidence
0–4	2.54	6.31	0.09	0.35	9.29
5–19	0.45	0.08	0.06	0.06	0.65
20–64	1.95	1.18	0.38	1.51	5.02
≥65	7.56	5.75	2.32	10.36	25.98
All ages	2.59	2.00	0.61	2.56	7.76
Sex and age group (years) related incidence
Incidence in men
0–4	2.31	6.33	0.09	0.43	9.15
5–19	0.49	0.05	0.03	0.05	0.63
20–64	1.90	1.23	0.48	1.75	5.36
≥65	8.23	7.36	2.85	14.34	32.78
All ages	2.54	2.17	0.69	3.09	8.49
Incidence in women
0–4	2.78	6.29	0.09	0.27	9.43
5–19	0.40	0.12	0.09	0.06	0.66
20–64	2.00	1.12	0.28	1.27	4.68
≥65	7.03	4.50	1.91	7.27	20.71
All ages	2.64	1.83	0.52	2.05	7.05
Sex incidence ratio (M:F)	0.96	1.19	1.33	1.51	1.20
Antibiotic resistant (%)
Penicillin	0	0	0.9b	0
Erythromycin	1.9	9.2	1.1	7.7
Clindamycin	0.5	5.4	0.3	1.1
Tetracycline	4.3	48.1	0.3	22.9

^aKruskal–Wallis equality-of-populations range test, χ² = 165.011 with 3 d.f., p 0.0001.

^bMIC values of two isolates were 0.5 and 1 mg/L and above the breakpoint of 0.25 mg/L; the MIC determinations were confirmed by a different laboratory.