Emergence and co-circulation of three multidrug resistant Shigella sonnei strains among men who have sex with men, Portland, Oregon, 2017-2019.

Shigella is a highly infectious bacterial pathogen spread via the fecal-oral route. Person to person spread during sexual contact among men who have sex with men (MSM) has been widely reported (1, 2). From January 2017 through May 2019, 74 culture confirmed multidrug resistant (MDR) shigellosis infections were reported in the Portland, Oregon area. Infections were caused by three divergent Shigella sonnei strains. To prevent additional illness and characterize the epidemiology of MDR shigellosis, a multifaceted investigation was conducted including expanded questionnaires, whole genome sequencing (WGS), antimicrobial susceptibility testing (AST), medical chart review, and sex partner notification. Among the 68 cases for which interviews were completed, 66 (97%) were among MSM. Patients reported having multiple sex partners (90%) and meeting on mobile dating or hook-up applications (63%). Forty percent reported methamphetamine use. Prevention and control challenges included low awareness of shigellosis among MSM and healthcare providers, inappropriate antimicrobial therapy, treatment failures, and limited sex partner elicitation. Results highlight the need for interventions to increase MSM and provider awareness of MDR Shigella spread through sexual contact to reduce shigellosis morbidity, limit ongoing transmission, and prevent future outbreaks. SummaryO_ST_ABSWhat is already known about this topic?C_ST_ABSMultidrug resistant (MDR) shigellosis among men who have sex with men (MSM) has been widely reported. Risk factors for specific MDR strains are of concern. What is added by this report?Between 2017 and 2019, three diverse MDR Shigella sonnei strains began co-circulating among sexually active MSM in the Portland, Oregon area. Patients reported multiple sex partners, use of mobile applications to meet partners, methamphetamine use, and housing insecurity. MDR shigellosis commonly resulted in hospitalization, treatment failure, and prolonged morbidity. What are the implications for public health practice?Interventions to increase MSM and provider awareness of MDR Shigella spread through sexual contact are necessary. To reduce morbidity and limit transmission, sexual health education should be provided to all adult patients with Shigella, and healthcare providers should order culture with antimicrobial susceptibility testing to inform antimicrobial therapy.