Volume 31, Number 4—April 2025
Research
Case–Control Study of Factors Associated with Hemolytic Uremic Syndrome among Shiga Toxin–Producing Escherichia coli Patients, Ireland, 2017–2020
Table 2
Reported symptoms and risk factors for case-patients and controls in study of HUS among patients with STEC, Ireland, 2017–2020*
Category |
HUS-STEC case-patients |
Non–HUS-STEC controls |
p value† |
Total |
Home in rural location | ||||
N | 24 (22) | 72 (17) | 0.073 | 96 (18) |
Y | 27 (25) | 142 (34) | 169 (32) | |
Missing |
57 (53) |
202 (49) |
259 (49) |
|
Reported vomiting | ||||
N | 21 (19) | 250 (60) | <0.05 |
271 (52) |
Y | 83 (77) | 131 (31) | 214 (41) | |
Missing |
4 (3.7) |
35 (8.4) |
39 (7.4) |
|
Reported bloody diarrhea | ||||
N | 44 (41) | 224 (54) | <0.05 |
268 (51) |
Y | 53 (49) | 149 (36) | 202 (39) | |
Missing |
11 (10) |
43 (10) |
54 (10) |
|
Outbreak associated | ||||
N | 68 (63) | 363 (87) | <0.05 |
431 (82) |
Y |
40 (37) |
53 (13) |
93 (18) |
|
Traveled abroad within past 10 d | ||||
N | 93 (86) | 345 (83) | 0.889 |
438 (84) |
Y | 8 (7.4) | 28 (6.7) | 36 (6.9) | |
Missing |
7 (6.5) |
43 (10) |
50 (10) |
|
Home drinking water | ||||
Public | 60 (56) | 226 (54) | 0.996 |
286 (55) |
Private well | 28 (26) | 107 (26) | 135 (26) | |
Group scheme, public supply | 7 (6.5) | 28 (6.7) | 35 (6.7) | |
Group scheme, private | 3 (2.8) | 13 (3.1) | 16 (3.1) | |
Missing |
10 (9.3) |
42 (10) |
52 (10) |
|
Consumed unpasteurized cheese or milk | ||||
N | 86 (80) | 346 (83) | 0.714 |
432 (82) |
Y | 4 (3.7) | 13 (3.1) | 17 (3.2) | |
Missing |
18 (17) |
57 (14) |
75 (14) |
|
Risk group | ||||
Not in a risk group | 62 (57) | 292 (70) | <0.05 |
354 (68) |
Child in crèche | 29 (27) | 59 (14) | 88 (17) | |
Attends other institution | 5 (4.6) | 8 (1.9) | 13 (2.5) | |
Childcare worker | 1 (0.9) | 14 (3.4) | 15 (2.9) | |
Food handler | 1 (0.9) | 8 (1.9) | 9 (1.7) | |
Missing |
10 (9.3) |
35 (8.4) |
45 (8.6) |
|
Recent outdoor recreational activities or recreational farmland contact‡ | ||||
N | 71 (66) | 289 (69) | <0.05 |
360 (69) |
Y | 26 (24) | 61 (15) | 87 (17) | |
Missing |
11 (10) |
66 (16) |
77 (15) |
|
Contact with farm animals | ||||
No contact | 56 (52) | 209 (50) | <0.05 | 265 (51) |
Regular contact§ | 26 (24) | 122 (29) | 148 (28) | |
One-off, e.g., visit to a pet farm | 9 (8.3) | 22 (5.3) | 31 (5.9) | |
Regular and one-off contact | 3 (2.8) | 11 (2.6) | 14 (2.7) | |
Contact of unknown nature | 4 (3.7) | 2 (0.5) | 6 (1.1) | |
Missing | 10 (9.3) | 50 (12) | 60 (11) |
*Values are no. (%) except as indicated. HUS, hemolytic uremic syndrome; STEC, Shiga toxin–producing Escherichia coli. †By χ2 test. ‡Hillwalking, camping, swimming in lakes, water sports, or beach. §Lives, works, or is cared for on a farm, or exposure to livestock, manure, slurry, or sewage through household contacts.
1These authors were co–principal investigators, contributed equally to this work, and share first authorship.