Table 4.

Association Between the Pathogen Quantity and Presence of Symptoms and Attributable Fractions^a

Norovirus Genogroup and Study	Odds Ratios per 1-Unit Increase in Cq Value (95% CI; P Value)	Attributable Fractions
Norovirus GI
Latin America	1.01 (0.91–1.13; P = .8)	1.1%
NVSN	1.07 (0.95–1.21; P = .3)	0.9%
Norovirus GII
Latin America	1.13 (1.05–1.21; P = .001)	16.0%
NVSN	1.13 (1.08–1.18; P < .0001)	16.2%

Abbreviations: CI, confidence interval; Cq, inverse measure of norovirus Ct value which was calculated as $Cq=41-Ct value$; Ct, cycle threshold; GI, genogroup I; GII, genogroup II; NVSN, New Vaccine Surveillance Network.

^aAll models except GI in the Latin America studies controlled for the detection of norovirus (positive vs negative), patients’ age, sex, and month of symptom onset. The model for GI in the Latin America studies included the detection of norovirus and month of symptom onset after backward elimination.