Table 2.

Prevalence of Giardia duodenalis infection according to demographic data and family characteristics.

Risk factor (total n*)	n	Positive results (%)	p	Risk Estimate (OR)	OR Confidence Interval (95%)
Gender (844)
Male	446	31 (6.9)	0.891	1.06	0.62 - 1.82
Female	398	26 (6.5)		1.00
Age (844)
0 - 5 years	403	31 (7.8)	0.268	1.41	0.82 - 2.43
6 - 15 years	441	26 (5.8)		1.00
Family structure
Number of adults (839)
1	42	5 (11.9)	0.187	2.02	0.76 - 5.36
> 1	797	50 (6.2)		1.00
Number of children (825)
1	349	24 (6.8)	0.777	1.10	0.63 - 1.91
> 1	476	30 (6.3)		1.00
Birth order (759)
Not the first	479	16 (6.8)	0.646	0.82	0.44 - 1.52
First	280	33 (5.7)		1.00
Mother's educational level (828)
No educated	13	3 (23.0)	0.047	4.49	1.20 - 16.84
Educated	815	51 (6.2)		1.00
Father's educational level (812)
No educated	14	6 (42.8)	< 0.001	12.26	4.08 - 36.82
Educated	798	46 (5.7)		1.00
Attendance of day care institution/Kindergarten (789)
Yes	640	43 (6.7)	0.592	0.82	0.42 - 1.60
No	149	12 (8.0)		1.00
Day care centre (< 3 years) (844)
Yes	193	14 (7.2)	0.745	1.11	0.59 - 2.07
No	651	43 (6.6)		1.00
Kindergarten (3-5 years) (844)
Yes	352	20 (5.6)	0.332	0.74	0.42 - 1.30
No	492	37 (7.5)		1.00
Helicobacter pylori infection (821)
Yes	56	25 (44.6)	0.037	1.82	1.05 - 3.15
No	756	235 (30.7)		1.00
Chronic disease (837)
Yes	87	5 (5.7)	0.824	0.82	0.32 - 2.11
No	750	52 (6.9)		1.00

* Numbers in parenthesis refers to sample size used for each variable after discharging children with missing data on the questionnaires. Statistically significant P values (< 0.05) are highlighted in boldface.