Controlling the Spread of Extended-Spectrum β-Lactamase-Producing <i> Escherichia coli</i> (ESBL-EC) in the Community: A Mathematical Model Simulating Household Circulation and the Impact of Interventions

Abstract

Background: The best strategy to control ESBL-producing Escherichia coli (ESBL-EC) spread in the community is lacking. Our objective was to evaluate the impact of hand hygiene (HH) improvement and reduction in antibiotic use on the within-household transmission of ESBL-EC . Methods: We developed an individual-based transmission model parametrised with data on daily contacts, HH practices, and antibiotic exposure in the community. We modelled four hypothetical households: two adults, family with a child/baby and family with a child and baby. We introduced in a household a single ESBL-EC colonised person and simulated the transmission dynamics of ESBL-EC over a one-year time horizon. Findings: The probability of ESBL-EC acquisition depended on the household composition and the profile of the initial carrier. In the two-person household, the probability of ESBL-EC acquisition by another household member was 5.3% (95% CI 5.0-5.6) and 6.6% (6.3-6.9) when the index person was a woman or a man, respectively. In a four-person household, the probability of acquisition varied from 61.4% (60.9-62.0) to 68.8% (68.3- 69.3) and was the highest when the index patient was the baby. Improving HH by 50% reduced the probability of transmission by 33-62%, according to the household composition and the category of the initial carrier. Antibiotic restriction by 50% reduced the transmission by 2-6%. Interpretation: Our findings suggest that the acquisition of ESBL-EC is frequent in households and especially those with a baby. Antibiotic reduction had little impact on ESBL-EC. Improvement of hygiene in the community could help prevent transmission of ESBL-EC. Funding Statement: This study was supported by the IAME research unity of French Institute for Medical Research (INSERM). Declaration of Interests: All authors declare no competing interests. Acknowledgments Ethics Approval Statement: Missing.