Azithromycin and Ciprofloxacin Treatment Outcomes During an Outbreak of Multidrug-Resistant Shigella sonnei Infections in a Retirement Community—Vermont, 2018

Details

• Alternative Title:
  Clin Infect Dis
• Personal Author:
  Gharpure, Radhika ; Friedman, Cindy R. ; Fialkowski, Veronica ; Collins, Jennifer P. ; Strysko, Jonathan ; Marsh, Zachary A. ; Chen, Jessica C. ; Meservey, Elizabeth H. ; Adediran, Azizat A. ; Schroeder, Morgan N. ; Wadhwa, Ashutosh ; Fullerton, Kathleen E. ; Francois Watkins, Louise
  More +
• Description:
  Background. ; In 2018, the Centers for Disease Control and Prevention and the Vermont Department of Health investigated an outbreak of multidrug-resistant Shigella sonnei infections in a retirement community that offered a continuum of care from independent living through skilled nursing care. The investigation identified 24 culture-confirmed cases. Isolates were resistant to trimethoprim-sulfamethoxazole, ampicillin, and ceftriaxone, and had decreased susceptibility to azithromycin and ciprofloxacin. ; Methods. ; To evaluate clinical and microbiologic response, we reviewed inpatient and outpatient medical records for treatment outcomes among the 24 patients with culture-confirmed S. sonnei infection. We defined clinical failure as diarrhea (≥3 loose stools per day) for ≥1 day after treatment finished, and microbiologic failure as a stool culture that yielded S. sonnei after treatment finished. We used broth microdilution to perform antimicrobial susceptibility testing, and whole genome sequencing to identify resistance mechanisms. ; Results. ; Isolates contained macrolide resistance genes mph(A) and erm(B) and had azithromycin minimum inhibitory concentrations above the Clinical and Laboratory Standards Institute epidemiological cutoff value of ≤16 μg/mL. Among 24 patients with culture-confirmed Shigella infection, 4 were treated with azithromycin; all had clinical treatment failure and 2 also had microbiologic treatment failure. Isolates were susceptible to ciprofloxacin but contained a gyrA mutation; 2 patients failed treatment with ciprofloxacin. ; Conclusions. ; These azithromycin treatment failures demonstrate the importance of clinical breakpoints to aid clinicians in identifying alternative treatment options for resistant strains. Additionally, these treatment failures highlight a need for comprehensive susceptibility testing and systematic outcome studies, particularly given the emergence of multidrug-resistant Shigella among an expanding range of patient populations.
• Subjects:
  • Anti-Bacterial Agents
  • Azithromycin
  • Ciprofloxacin
  • Disease Outbreaks
  • Drug Resistance, Bacterial
  • Dysentery, Bacillary
  • Humans
  • Macrolides
  • Microbial Sensitivity Tests
  • Retirement
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• Keywords:
  • antibiotic treatment failure
  • multidrug resistance
  • azithromycin
  • ciprofloxacin
  • Shigella sonnei
• Source:
  Clin Infect Dis. 74(3):455-460
• Pubmed ID:
  33993224
• Pubmed Central ID:
  PMC8963682
• Document Type:
  Journal Article
• Funding:
  CC999999/ImCDC/Intramural CDC HHSUnited States/
• Volume:
  74
• Issue:
  3
• Download URL:
  https://stacks.cdc.gov/view/cdc/115775/cdc_115775_DS1.pdf
• File Type:
  [PDF - 440.90 KB]
• Collection(s):
  CDC Public Access
• Main Document Checksum:
  urn:sha-512:a6a1b574cd59fda2bcf37760115fb52906e106496b2758852d58446255b5c9a55641ef4176a6012f9da44024d0779e2908768bd5265f5a126abc2d69a1601593