Notification from the Los Angeles County Department of Public Health
Notification from the Los Angeles County Department of Public Health
LAC DPH Health Advisory:
Increase in Extensively Drug-Resistant Shigella Cases in LAC
June 5, 2025
This message is intended for primary care, emergency, and urgent care providers.
Please distribute as appropriate.
Key Messages
  • Extensively drug-resistant (XDR) Shigella cases are increasing in Los Angeles County (LAC).
  • XDR Shigella disproportionately affects men who have sex with men (MSM) and people living with HIV.
  • As Pride events begin this week, healthcare providers are asked to be vigilant for potential XDR Shigella infections and to test, treat, and report cases appropriately.
  • Due to rising antibiotic resistance, antibiotics should be reserved for patients with severe illness or underlying risk factors. Most Shigella infections are self-limiting.
Situation
Los Angeles County is experiencing an increase in extensively drug-resistant (XDR) shigellosis cases. In 2024, 68 cases were identified compared to 45 in 2023 and 5 in 2021. The first case in LAC was identified in 2017.
CDC defines XDR Shigella as strains that are resistant to all commonly recommended empiric and alternative antibiotics — azithromycin, ciprofloxacin, ceftriaxone, trimethoprim sulfamethoxazole (TMP-SMX), and ampicillin.
Among adults, Shigella disproportionately affects MSM, people living with HIV, individuals experiencing homelessness, and international travelers. XDR Shigella has emerged in these same populations, particularly among MSM and people with HIV. In Los Angeles County, people living with HIV accounted for approximately one-third of XDR shigellosis cases reported between January 2019 and 2024 (LAC DPH, unpublished data).
Clinicians have limited antimicrobial options for treating XDR Shigella. Shigella is easily transmissible, and XDR strains can spread antimicrobial resistance genes to other enteric pathogens. Given these public health risks, healthcare providers are urged to take steps to help prevent the spread of XDR Shigella in Los Angeles County.
Actions Requested of Providers
  • Suspect shigellosis in patients with acute diarrhea, particularly in those who are MSM, immunocompromised, or experiencing homelessness.
  • Order a stool culture with antibiotic susceptibility testing (AST) for patients who will receive antibiotic treatment. See Testing below.
  • Limit antibiotics to patients with severe illness or underlying risk factors. If antibiotics are needed before AST results are available, refer to the LA County Shigella antibiogram. See Treatment below.
  • Educate patients with shigellosis in transmission prevention, including safe sex practices—patients should not have sex until at least 2 weeks after diarrheal symptoms end. Encourage patients to contact you if symptoms do not improve within 48 hours after beginning antibiotics.
  • Report all shigellosis infections to Public Health within one working day. See Reporting below. .
Testing
If ordering diagnostic testing for Shigella, stool culture is preferred for patients who may require antimicrobial treatment.
If a culture-independent diagnostic test (CIDT, e.g. Gastrointestinal Panel) is performed, request that the clinical laboratory perform reflex culture if Shigella is detected.
AST should include a complete antibiotic profile for Shigella: azithromycin, ciprofloxacin, ceftriaxone, trimethoprim-sulfamethoxazole (TMP-SMX), and ampicillin.
Treatment
Most patients recover from shigellosis without antimicrobial treatment. Oral rehydration is sufficient for many cases.
Antimicrobial therapy is indicated for patients with severe or prolonged illness, those who are hospitalized, or those with underlying risk factors such as immunocompromising conditions (e.g., HIV/AIDS or immunosuppressive therapy).
If antibiotics are needed, treatment should be guided by the best available data:
  • Use the Los Angeles County Shigella antibiogram to guide presumptive therapy.
  • For patients with severe disease (e.g., bacteremia, hospitalized) or those who are immunocompromised, empiric treatment with a carbapenem is recommended pending drug susceptibility testing results. (Source: CDC Yellow Book)
  • Adjust treatment based on AST results when available. Avoid prescribing fluoroquinolones for ciprofloxacin minimum inhibitory concentration (MICs) in the 0.12–1.0 μg/mL range.
  • Consult with a specialist knowledgeable in treating antibiotic-resistant bacteria when treating XDR shigellosis to determine the best treatment options.
Reporting
Providers should report shigellosis infections to Public Health within one working day.
Los Angeles County DPH Acute Communicable Disease Control:
  • Fax a CMR to 888-397-3778 or 213-482-5508 or send via secure email to RPU@ph.lacounty.gov, or
  • Call 888-397-3993 weekdays 8:30am–5:00pm 
  • For consultation call 213-240-7941.
Long Beach Health and Human Services:
Pasadena Public Health Department:
Additional Resources
This communication was sent by Dr. Sharon Balter, Director of Acute Communicable Disease Control Program, Los Angeles County Department of Public Health.
To view a printable PDF of this communication and other LAHAN communications, please visit publichealth.lacounty.gov/lahan.
If this message was forwarded to you, please join LAHAN here.
Manage your profile/DPH subscriptions
Opt out of all DPH subscriptions (LAHAN and Rx) using TrueRemove®
Got this as a forward? Sign up to receive our future emails.
Want to view this online? View online
241 N. Figueroa St. Suite 275
Los Angeles, CA | 90012 US
This email was sent to .
To continue receiving our emails, add us to your address book.
powered by emma
Subscribe to our email list.