Report Reveals More B. multivorans Cases in Hospitals Tied to Brand of Ice Machine

A new report has revealed that 23 “previously unreported B. multivorans cases occurred during 2020-2024: 13 at a northern California hospital, eight at a hospital in Colorado, and two additional cases at one of the southern California hospitals. All environmental and clinical isolates were highly genetically similar. The same brand of ice machine and the same filters, descaling, and sanitizing products were used by all four hospitals.”

These 23 cases come in addition to 23 other cases that were reported during 2021-2022 at two southern California hospitals. In addition, “whole genome sequencing indicated that all clinical and ice machine isolates were highly genetically similar (0–14 single nucleotide variant differences across 81% of the selected reference genome). Recommendations from public health officials to halt the outbreak included avoiding ice and tap water during clinical care activities. An investigation is ongoing to determine possible sources of ice machine contamination.”

Outbreaks of organisms like these “have been associated with contaminated medications, aqueous medical products, and medical devices and are of clinical importance because these organisms can be antibiotic-resistant and can lead to severe infections, especially among immunocompromised and critically ill patients.”

Genomic relatedness of “the clinical and environmental B. multivorans isolates and identification of the outbreak strain in the same brand of ice machine raises the possibility of a contaminated ice machine component or associated product (e.g., descaling and sanitizing products) leading to contamination of the dispensed ice and water.” The authors of the report suggest that "healthcare facilities should devise and implement a water management program and identify all potential pathways of water transmission to minimize patients’ risks for infection.”