An outbreak of Ralstonia insidiosa infection: a case series and an epidemiologic investigation in a pediatric hospital

Abstract

Ralstonia insidiosa is not usually considered an etiologically significant microorganism capable of causing infections. This article presents a retrospective analysis of a series of hospital-acquired infections caused by R. insidiosa in 8 comorbid patients at a pediatric hospital from August 2023 to May 2024, describing the diagnostic challenges and treatment experience. The analysis included 82 microbiological samples from 42 patients, but Ralstonia was only etiologically significant in the development of infection in 8 patients (19%), with 7 of them in the intensive care unit and 1 in the immunology and rheumatology department. In 6 patients, the microorganism caused pneumonia, in 1 patient – both pneumonia and catheter-associated bloodstream infection, and in another – skin and soft tissue infection. In 7 out of 8 cases, microbiological eradication and resolution of laboratory inflammatory activity were achieved using fluoroquinolones, cotrimoxazole, tigecycline, piperacillin/tazobactam, or their combinations; the experience with carbapenem therapy, despite in vitro sensitivity, was unsuccessful. In 1 patient with pneumonia, microbiological results were obtained post-mortem, revealing growth of Ralstonia insidiosa in association with C. parapsilosis in the lung autopsy material. An epidemiological investigation was conducted, which identified a contamination of 0.05% chlorhexidine solution, which was used for sanitizing intubation tubes, tracheostomies, wounds, and as an antiseptic for skin and catheter cannulas. The results of this work highlight the importance of regular microbiological monitoring, the contribution of atypical pathogens to the development of hospitalacquired infections, and the potential for conducting epidemiological investigations to prevent further adverse events in medical care.