The clinical presentation of culture-positive and culture-negative, qPCR-attributable shigellosis in the Global Enteric Multicenter Study and derivation of a Shigella severity …

Background Shigella is a leading cause of childhood diarrhea and target for vaccine development. Microbiologic and clinical case definitions are needed for pediatric field vaccine efficacy trials. Methods We compared characteristics of moderate to severe diarrhea (MSD) cases in the Global Enteric Multicenter Study (GEMS) between children with culture positive Shigella to those with culture-negative, qPCR-attributable Shigella (defined by an ipaH gene cycle threshold <27.9). Among Shigella MSD cases, we determined risk factors for death and derived a clinical severity score. Results Compared to culture-positive Shigella MSD cases (n=745), culture-negative/qPCR-attributable Shigella cases (n=852) were more likely to be under 12 months, stunted, have a longer duration of diarrhea, and less likely to have high stool frequency or a fever. There …