Table 2.

Relative risk estimates for water contact by month.

Month	Prevalence	Relative Risk	95% CI	Std. error	p-value
June	0.75	1.03	(0.98, 1.09)	0.03	0.20
October	0.58	0.95	(0.89, 1.03)	0.04	0.22
May	0.75	1.04	(0.97, 1.13)	0.04	0.25
April	0.73	1.04	(0.95, 1.14)	0.05	0.45
August	0.76	1.03	(0.94, 1.13)	0.05	0.51
September	0.70	0.98	(0.89, 1.07)	0.05	0.64
July	0.77	0.98	(0.91, 1.06)	0.04	0.68

These estimates are based on a main-effects log-linear regression, and are also adjusted for age category and village. The relative risks reflect the difference in risk of infection between exposure at the mean value for that month and zero exposure.