. 2019 Jan 24;38(4):801–809. doi: 10.1007/s10096-019-03475-5

Table 1.

Demographic and clinical characteristics of cases categorised with high-virulent (number of cases; N = 475) versus low-virulent (N = 652) Shiga toxin-producing Escherichia coli (STEC) infections, notified to the Norwegian Surveillance System for Communicable Diseases (MSIS), Norway, 2007–2017 (N = 1127)

Variable	Category	All cases^a (N = 1127)		High-virulent STEC cases^a (N = 475)		Low-virulent STEC cases^a (N = 652)		Chi-square p value^b
Variable	Category	N	%	N	%	N	%	Chi-square p value^b
Sex	Female	585	52	258	54	327	50	0.167
Sex	Male	542	48	217	46	325	50	0.167
Age group	≤ 5	458	41	242	51	216	33	< 0.001
	6–15	101	9	39	8	62	9
	16–41	295	26	108	23	187	29
	42–64	163	14	48	10	115	18
	65+	110	10	38	8	72	11
Seasonality	Winter	204	18	66	14	138	21	0.008
	Spring	168	15	71	15	97	15
	Summer	360	32	170	36	190	29
	Autumn	395	35	168	35	227	35
Reported infected abroad	No	747	74	332	76	415	73	0.255
Reported infected abroad	Yes	260	26	105	24	155	27	0.255
Hospitalised	No	750	71	260	59	490	79	< 0.001
Hospitalised	Yes	311	29	182	41	129	21	< 0.001

^aThe numbers and proportions reported per column for each characteristic use the number of cases with available (known) information regarding each characteristic

^bA p value of ≤ 0.05 (italicised) was considered statistically significant