Table 6. Odds ratios for GI and diarrhea associated with exposure to varying levels of HAdV and E. coli at East Fork Lake, Ohio.

Water Quality Index	Any GI Illness			Diarrhea
	Cases/n (%)	OR (95% CI)	Wald (p)	Cases/n (%)	OR (95% CI)	Wald(p)
Group 1: Low HAdV & Low E. coli (HAdV <DLa, log E. coli <1.05)	3/187 (1.6)	Referent		3/189 (1.6)	Referent
Group 2: Low HAdV & High E. coli (HAdV <DL, log E. coli>1.05)	16/199 (8.0)	5.4 (1.5–19)	0.011	9/199 (4.5)	2.9 (0.74–12)	0.126
Group 3: High HAdV & Low E. coli (HAdV> DL, log E. coli <1.05)	11/126 (8.7)	5.9 (0.88–39)	0.067	9/127 (7.1)	4.7 (0.56–40)	0.153
Group 4: High HAdV & High E. coli (HAdV> DL, log E. coli>1.05)	8/88 (9.0)	6.1 (1.5–25)	0.011	7/90 (7.8)	5.2 (1.3–22)	0.023

^aDetection Limit.