TABLE 4.

Incidence of Entamoeba histolytica reinfection in children with and without prior stool anti-CRD IgA^a

No. of previous infections	Previous stool anti-CRD IgA	Person-time (days)	No. of infections	Incidenceb	Adjusted relative hazard	95% CI	P value
1	Negative	26,192	53	0.20
1	Positive	73,150	47	0.06	0.28	0.18, 0.44	<0.0001
2	Negative	17,236	32	0.18	0.85	0.53, 1.36	0.50
2	Positive	25,859	18	0.07	0.30	0.17, 0.50	<0.0001
≥3	Negative	12,465	35	0.28	1.20	0.74, 1.95	0.45
≥3	Positive	13,201	13	0.10	0.40	0.20, 0.79	0.008

^aIncidence of Entamoeba histolytica reinfection and adjusted relative risk for repeat infections were calculated using the Andersen-Gill proportional hazards method adjusted for age in months, gender, baseline serum anti-E. histolytica IgG, and area of residence within Mirpur. Siblings (n = 36) were excluded from this analysis. See Table 3 for definition of person-time.

^bNo. of infections per 100 child-days.