Minimally Invasive Saliva Testing to Monitor Norovirus Infection in Community Settings

Author(s): Pisanic, Nora; Ballard, Sarah-Blythe; Colquechagua, Fabiola D; Francois, Ruthly; Exum, Natalie; Yori, Pablo Penataro; Schwab, Kellogg J; Granger, Douglas A; Detrick, Barbara; Olortegui, Maribel Paredes; Mayta, Holger; Sanchez, Gerardo J; Gilman, Robert H; Heaney, Christopher D; Vinje, Jan; Kosek, Margaret N | Abstract: BACKGROUND:Norovirus is a leading cause of acute gastroenteritis worldwide. Routine norovirusdiagnosis requires stool collection. The goal of this study was to develop and validate a noninvasive method to diagnose norovirusto complement stool diagnostics and to facilitate studies on transmission. METHODS:A multiplex immunoassay to measure salivary immunoglobulin G (IgG) responses to 5 common norovirusgenotypes (GI.1, GII.2, GII.4, GII.6, and GII.17) was developed. The assay was validated using acute and convalescent saliva samples collected from Peruvian children l5 years of age with polymerase chain reaction (PCR)-diagnosed norovirusinfections (n = 175) and controls (n = 32). The assay sensitivityand specificity were calculated to determine infection status based on fold rise of salivary norovirusgenotype-specific IgG using norovirusgenotype from stool as reference. RESULTS:The salivary assay detected recent norovirusinfections and correctly assigned the infecting genotype. Sensitivity was 71% and specificity was 96% across the evaluated genotypes compared to PCR-diagnosed norovirusinfection. CONCLUSIONS:This saliva-based assay will be a useful tool to monitor norovirustransmission in high-risk settings such as daycare centers or hospitals. Cross-reactivity is limited between the tested genotypes, which represent the most commonly circulating genotypes.