Table 3. Final multivariable model of risk factors for sporadic cryptosporidiosis, Allerdale and Copeland residents, March 1, 1996, to August 31, 2002.

Risk factors	Case-patients	Controls	Adjusted odds ratio*	Lower 95% CI†	Upper 95% CI	p value
Sex
Female	85	265	1	0.45	1.184	0.202
Male	90	272	0.73
Age
<1–5	96	300	1.002/y	0.938	1.021	0.872
6–15	54	157
16+	25	70
Water sources and water supply zones						0.556
Crummock Lake
Crummock North	39	111	1
Crummock South	23	62	1.262	0.547	2.913
Ennerdale Lake
Ennerdale North	32	107	1.25	0.594	2.63
Ennerdale South	14	46	0.556	0.164	1.881
Other sources
Millom	22	64	1.502	0.686	3.288
Quarry Hill	22	58	0.703	0.273	1.81
Hausegill	3	5	1.356	0.22	8.34
Ayknott	2	7	1.016	0.1	10.29
Underscar	3	9	0.983	0.1	9.18
Fellside	0	1	0.005	0	∞
Bridgend	0	2	0.004	0	∞
Mixed public supplies	12	55	0.893	0.32	2.494
Private water supplies	3	10	0.1	0.007	1
Usual daily volume of cold unboiled tap water drunk at home			1.543 per pint	1.212	1.965	< 0.001
<1/4 pint	25	122
1/4–1 pint	78	260
>1–2 pints	46	106
>2 pints	22	42
Contact with a cattle farm
Yes	19	29	4.532	1.757	11.69	0.002
No	144	475
Contact with a noncattle farm
Yes	17	24	3.809	1.677	8.651	0.002
No	146	471
Feed pet leftovers
Yes	14	19	3.746	1.214	11.56	0.021
No	161	515
Interval of study						0.585
March 1, 1996–February 29, 2000	153	468	1
March 1, 2000–July 31, 2000	4	16	0.965	0.235	3.958
August 1, 2000–February 20, 2001	6	16	1.115	0.319	3.895
February 21, 2001–January 21, 2002	6	18	0.367	0.078	1.72
January 11, 2002–August 31, 2002	6	19	0.485	0.138	1.701

*Adjusted for accidentally touching animal feces, feeding pets biscuits, feeding pets raw vegetables, contact with anyone outside the household with a history of diarrhea, type of sewage system to the house, consumption of mixed salad, and local authority of residence.
†CI, confidence interval.