Infections from Shigella spp. and Enteroinvasive Escherichia coli (EIEC) are considered leading causes of symptomatic diarrheal disease, globally. However, there is a paucity of case-control studies from Caribbean nations to guide regional public health priorities and interventions. A case-control study was conducted within a larger cross-sectional healthcare study in Haïti. Participant households were identified using a geospatially randomized method; families with children under 5 years were consented and enrolled. Rectal swabs from child participants were tested for Shigella spp./EIEC by qPCR using the ipaH target. Two case-definitions were used: 'diarrheal symptom' (DS) cases were defined as those reporting diarrheal symptoms ≤7 days ago; 'acute diarrhea' (AD) cases were defined as those reporting diarrheal symptoms ≤7 days ago with ≥3 loose stools in the past 24 hours and onset <7 days ago. Of 868 households screened, 568 were enrolled with 794 participating children; samples from 732 children were analyzed. Rates of Shigella spp./EIEC. detection among DS cases and controls were 11.4% (22/193) and 6.1% (33/539), respectively. Rates of detection among AD cases and controls were 18.6% (8/43) and 6.8% (47/689), respectively. The adjusted odds of having DS increased by 84% (aOR=1.84; 95%CI 1.02 to 3.27) and having AD increased by 183% (aOR=2.83; 95%CI 1.14 to 6.36) when Shigella spp./EIEC was detected. The attributable fractions for DS and AD were 5.62% (95%CI 0.44% to 10.9%) and 12.6% (95%CI 0% to 25.3%), respectively. Rates of bloody diarrhea (dysentery) were minimal (<1%, 6/732). Within this case-control study in Haïti, Shigella spp./EIEC detection was common and attributed to symptomatic disease. These results align with prior global health studies. Shigella spp./EIEC represent an important public health target for intervention once the security situation in Haïti stabilizes.

The authors have declared no competing interest.

This work was supported by the National Institutes of Health [DP5OD019893] to EJN and [R01 AI135115] to DTL as well as the Children's Miracle Network. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.

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The details of the IRB/oversight body that provided approval or exemption for the research described are given below:

IRB of University of Florida gave ethical approval for this work (IRB201703246). IRB of Comité National de Bioéthique (National Bioethics Committee of Haïti) gave ethical approval for this work (Ref:1718-35).

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