Table 1.

Frequency of G. lamblia in Mazandaran Province by demographic data and risk factors

Risk factors	No. specimens examined	No. positive (%)	OR (95% CI)	P value
Age
< 5	648	25 (3.8%)	1	–
5–9	828	78 (9.4%)	0.3 (0.2–0.6)	< 0.0001
10–14	722	36 (4.9%)	0.7 (0.4–1.3)	0.3
15–24	988	31 (3.1%)	1.2 (0.6–2.1)	0.4
25–39	913	29 (3.1%)	1.2 (0.6–2.1)	0.4
≥ 40	689	23 (3.3%)	1.1 (0.6–2.1)	0.6
Sex
Male	2579	122 (4.7%)
Female	2209	100 (4.5%)	1.04 (0.7–1.3)	0.7
Residence
Rural	2273	146 (6.4%)
Urban	2515	76 (3.0%)	2.2 (1.6 – 2.9)	< 0.0001
Consumed water
Tab water	3984	186 (4.7%)	1
Shaft water	308	9 (2.9%)	1.6 (0.8–3.6)	0.1
Mineral water	496	27 (5.4%)	0.8 (.5–1.3)	0.4
Job
Student	1587	71 (4.4)	1	–
Private business	1085	52 (4.7)	1.09 (0.7–1.5)	0.6
Housewife	1139	43 (3.7)	1.2 (0.8–1.7)	0.3
Government employee	348	11 (3.1)	1.7 (0.9–3.7)	0.07
Agriculture	629	45 (7.1)	0.06 (0.04–0.1)	< 0.0001
Education
Illiterate	943	58 (6.2%)	1	–
Primary	1477	85 (5.8%)	0.6 (.4–1.1)	0.7
High school	1646	65 (3.9%)	0.5 (0.3–0.8)	0.01
University	722	14 (1.9%)	0.8 (0.5–1.3)	< 0.0001
Contact to domestic animals
Yes	2427	121 (4.9)	1.2 (0.9–1.5)	0.1
No	2361	101 (4.2)
Season
Winter	1167	39 (3.3%)	1	–
Spring	1196	59 (4.9%)	0.6 (0.4–1.1)	0.06
Summer	1256	76 (6.1%)	0.5 (0.3–0.8)	0.002
Autumn	1169	48 (4.1%)	0.8 (0.5–1.32	0.4
Anti parasitic drug consumption
Yes	1086	46 (4.2%)	0.8 (0.6–1.2)	0.5
No	3702	176 (4.8%)