INVASIVE Aeromonas infections were uncommon yet severe in a four-year rural U.S. review of cases.
Incidence and Clinical Spectrum
This retrospective analysis identified 26 Aeromonas isolates in 21 patients across October 2018 to December 2022, with a median age of 56 years. Six isolates were recovered from blood cultures, most linked to biliary infection, and soft tissue infection was documented in 14 patients. One patient presented with acute cholecystitis. The series underscores that Aeromonas infections, while rare, can lead to invasive disease in rural settings and require prompt recognition.
Species Distribution and Microbiology
Eighteen isolates were A. hydrophila or A. caviae, two were A. sobria, and one was A. veronii. Aeromonas was the sole pathogen in ten cases. Polymicrobial infection was common, occurring in eleven infections, with co-pathogens that included gram positive cocci, gram negative rods, and anaerobes. This pattern highlights the need for empiric coverage that anticipates mixed flora when Aeromonas infections are suspected.
Management, Procedures, and Outcomes
Nine patients underwent ten interventions. These included wound debridement, endoscopic retrograde cholangiopancreatography, percutaneous cholecystostomy, and laparoscopic cholecystectomy. Preferred antibiotic choices were fluoroquinolones, third or fourth generation cephalosporins, trimethoprim sulfamethoxazole, and doxycycline. All infections were successfully treated. One patient died due to metastatic pancreatic cancer, not directly from infection. The combined use of timely source control with appropriate antibiotics appeared central to favorable outcomes.
Implications for Practice
Clinicians should consider Aeromonas infections in invasive presentations, especially when biliary disease or soft tissue involvement is present. Awareness of biliary tropism is important for early imaging, surgical consultation, and selection of empiric therapy that addresses possible polymicrobial infection. Tailored antibiotics guided by local susceptibility and definitive source control remain essential.
Reference: Henrichs J et al. Experience with Invasive Aeromonas Infections at a Rural Hospital in the United States of America. Surg Infect (Larchmt). 2025. doi: 10.1177/10962964251389150.
