Abstract
Infections from Shigella spp./enteroinvasive Escherichia coli (EIEC) are considered leading causes of diarrheal disease globally. However, there is a notable paucity of studies from Caribbean nations to guide regional public health interventions. A case-control study was conducted as part of a cross-sectional healthcare study in Haiti. Households were identified using a geospatially randomized method, and families with children under 5 years of age were consented and enrolled. Rectal swabs from child participants were tested for Shigella spp./EIEC via real-time polymerase chain reaction testing using the invasion plasmid antigen H gene target. Two case definitions were used: "diarrheal symptom" (DS) cases were defined as those reporting DSs ≤7 days ago; "acute diarrhea" (AD) cases were defined as those who also presented with ≥3 loose stools in the past 24 hours and onset <7 days ago. A total of 568 households were enrolled, and samples from 732 children were analyzed. The rates of Shigella spp./EIEC detection were 11% (22/193) and 6% (33/539) among DS cases and controls, respectively, and 19% (8/43) and 7% (47/689) among AD cases and controls, respectively. Shigella spp./EIEC was attributed to DS in 6% (95% CI: 0.4%-11%) of cases and AD in 13% (95% CI: 0%-25%) of cases. The adjusted odds of having DS increased by 84% (adjusted odds ratio [aOR] = 1.84; 95% CI: 1.02-3.27) and AD increased by 183% (aOR = 2.83; 95% CI: 1.14-6.36) when Shigella spp./EIEC was detected. The rates of bloody diarrhea were minimal (<1%; 6/732). In the present case-control study, the detection of Shigella spp./EIEC was common and attributed to symptomatic disease. These results align with previous global health studies. Shigella spp./EIEC represent an important public health target for intervention once the security situation improves in Haiti.