Table 2.

Risk factors for E. histolytica infection in Hanam province, Vietnam (multivariable conditional logistic regression analysis).

Risk factors	Matched OR	95% CI	P-value
Household's socioeconomic status (versus good)
- average	4.3	1.3-14.0	0.02
- poor	2.2	0.6-7.4	0.22
Household's sanitary conditions (versus good)
- average	0.8	0.3-2.3	0.68
- poor	1.6	0.6-4.6	0.38
Household with tap water (yes versus no)	1.3	0.5-3.1	0.57
Close contact with domestic animals in household (yes versus no)	5.9	1.9-18.9	0.003
Handling animal excreta in field work (yes versus no)	0.2	0.1-0.7	0.01
Direct contact with Nhue river water during field work (yes versus no)	0.4	0.1-1.1	0.07
Use of Nhue river water to irrigate fields (yes versus no)	3.7	0.4-33.1	0.24
Washing hands with soap after field work (versus frequently)
- sometimes	1.7	0.5-5.8	0.40
- rarely	3.4	1.1-10.0	0.03