UCSF

Little is known about enteropathogen seroepidemiology among children in low-resource settings. We measured serological IgG response to eight enteropathogens ( Giardia intestinalis, Cryptosporidium parvum, Entamoeba histolytica, Salmonella enterica , enterotoxigenic Escherichia coli, Vibrio cholerae, Campylobacter jejuni , norovirus) using multiplex bead assays in cohorts from Haiti, Kenya, and Tanzania. By age 2 years, most children had evidence of exposure by IgG response to the pathogens studied. We discovered a shift in IgG distributions for many pathogens as children age, caused by boosting and waning from repeated exposures, which complicates interpretation of seroprevalence among older children. Longitudinal profiles revealed important variation in enteropathogen IgG response above seropositivity cutoffs, underscoring the importance of longitudinal designs to estimate seroincidence rates as a measure of force of infection. In longitudinal cohorts there was a linear relationship between seroprevalence and prospective seroincidence rates, suggesting the two measures provide similar information about variation in pathogen transmission.