Volume 9, Number 2—February 2003
Research
Risk Factors for Sporadic Giardiasis: a Case-Control Study in Southwestern England
James M. Stuart*
, Hilary J. Orr*, Fiona G Warburton†, Sugarthinny Jeyakanth†, Carolyn Pugh‡, Ian Morris‡, Joyshri Sarangi§, and Gordon Nichols¶
, Hilary J. Orr*, Fiona G Warburton†, Sugarthinny Jeyakanth†, Carolyn Pugh‡, Ian Morris‡, Joyshri Sarangi§, and Gordon Nichols¶Table 1
Single variable analysis of risk factors for giardiasis: drinking water exposures
| Risk factor | Cases (n=192) | Controls (n=492) | Matched odds ratio (95% CI)a | p value | |
|---|---|---|---|---|---|
| Consumed tap water |
No |
17 |
79 |
||
| Yes |
174 |
410 |
2.3 (1.1 to 4.9) |
0.02 |
|
| Usual no. of glasses of tap water consumed per day (glass=approx 1/3 pint) |
0.0 |
17 |
79 |
||
| 0.5–1.0 |
22 |
71 |
|||
| 1.5–2.0 |
52 |
150 |
|||
| 2.5–3.0 |
23 |
46 |
|||
| 3.5–4.0 |
23 |
41 |
|||
| 4.5–5.0 |
20 |
41 |
|||
| >5.0 |
33 |
61 |
1.2 (1.1 to 1.4)b |
<0.0001 |
|
| Consumed bottled water |
No |
154 |
406 |
||
| Yes |
38 |
83 |
1.6 (0.9 to 2.9) |
0.1 |
|
| Usual no. of glasses of bottled water consumed per day |
0 |
154 |
406 |
||
| 1 |
12 |
29 |
|||
| 2 |
19 |
32 |
|||
| 3 |
5 |
13 |
|||
| 4 |
1 |
8 |
1.2 (0.9 to 1.6)b |
0.3 |
|
| Used water filter at home |
No |
157 |
387 |
||
| Yes |
34 |
104 |
0.9 (0.5 to 1.7) |
0.8 |
|
| Type of water supply |
Public |
187 |
483 |
||
| Private |
3 |
3 |
0.05 (0.002 to 1.11) |
0.04 |
|
| Had a disruption in the water supply | No |
124 |
447 |
||
| Yes | 6 | 11 | 3.6 (0.6 to 20.8) | 0.2 | |
aCI, confidence intervals.
bFor each additional glass.
