Table 2. Losses regarding the return of stool samples for parasitological examination.

Variables	Category	Children who returned at least one sample (n = 635)		Children who returned no sample (n = 29)		p-value
		n	%	n	%
Cistern	Yes (Cistern group)	323	50.9	14	48.3	0.79
	No (Comparison group)	312	49.1	15	51.7
Child's sex	Female	297	46.8	18	62.1	0.11
	Male	338	53.2	11	37.9
Duration of pregnancy	Full term	475	76.0	13	72.2	0.70
	Less than full term	150	24.0	5	27.8
Preparation of fruit & vegetables prior to consumption	Washed with treated water	117	18.4	6	20.7	0.12
	Washed with untreated water	402	63.3	22	75.9
	Washed/disinfected with bleach or vinegar	116	18.3	1	3.4
Total family income	From R$ 0.00 to 100.00	48	7.7	4	14.3	0.40
	From R$ 101.00 to 500.00	389	62.6	15	53.6
	Above R$ 500.00	184	29.6	9	32.1