Extensively drug-resistant Pseudomonas aeruginosa causing infection outbreak.

Infections from a rare extensively drug-resistant strain of Pseudomonas aeruginosa have been identified in 12 states (CA, CO, CT, FL, NJ, NY, NV, TX, UT, WA, WI). Most of the infections were from patients who reported using artificial tears. Patients reported more than 10 brands of artificial tears, but most patients reported using Ezricare Artificial Tears, an over-the-counter product. Patients who were infected have experienced permanent vision loss resulting from a cornea infection, hospitalization, and one death has been reported due to a systematic infection (CDC, 2023). The University of California at San Diego’s Center for Innovative Phage Applications and Therapeutics have identified a bacteriophage with activity against the outbreak strain. A minimum inhibitory concentration for aztreonam-avibactam has been identified, however, clinical breakpoints have not been established for antimicrobial combination.


  • For recommendations from the CDC for Healthcare Providers, Clinical Laboratories, and the Public, visit the link here.
  • Clinicians interested in phage as a potential treatment option should contact IPATH at ipath@health.ucsd.edu.
  • Susceptibility testing for this combination to inform clinical decision making is available through
  • CDC – refer to CDC Test Directory.

Cited Resources

Centers for Disease Control and Prevention. (2023, February 1). Health Alert Network (HAN) – 00485. Centers for Disease Control and Prevention. Retrieved April 5, 2023, from https://emergency.cdc.gov/han/2023/han00485.asp