Genomic surveillance for comprehensive Shigella management

Abstract

In The Lancet Infectious Diseases, Giannoula S Tansarli and colleagues 1 Tansarli GS Long DR Waalkes A et al. Genomic reconstruction and directed interventions in a multidrug-resistant Shigellosis outbreak in Seattle, WA, USA: a genomic surveillance study. Lancet Infect Dis. 2023; (published online Jan 30.)https://doi.org/10.1016/S1473-3099(22)00879-9 Google Scholar have reported their whole-genome sequencing (WGS)-based analyses of sustained shigellosis in Seattle, WA, USA, and have revealed the contemporaneous emergence of Shigella sonnei and Shigella flexneri, likely introduced from abroad. Interestingly, of the 171 isolates identified in patients, the investigators show a predominance of S flexneri (112 [66%]) over S sonnei (55 [32%]) and cite similar observations from Australia and the UK. Historically, S sonnei has been predominant in high-income countries (HICs), particularly among men who have sex with men (MSM) whereas S flexneri predominates in low-income to middle-income countries (LMICs), where children are disproportionately affected. In parallel, of the 171 patients, Tansarli and colleagues reported that 78 (46%) patients were MSM, and 88 (52%) were people experiencing homelessness (PEH) and accentuated the incidence of shigellosis among PEH in HICs. Genomic reconstruction and directed interventions in a multidrug-resistant Shigellosis outbreak in Seattle, WA, USA: a genomic surveillance studyAn outbreak in Seattle was driven by parallel emergence of multidrug-resistant strains involving international transmission networks and domestic transmission between at-risk populations. Genomic analysis elucidated not only outbreak origin, but directed optimal approaches to testing, treatment, and public health response. Rapid diagnostics combined with detailed knowledge of local epidemiology can enable high rates of appropriate empirical therapy even in multidrug-resistant infection. Full-Text PDF