# Outbreak of bacteremia caused by Ralstonia insidiosa isolated from a contaminated blood gas syringe

## TL;DR

A hospital outbreak of Ralstonia insidiosa bacteremia was traced to contaminated blood gas syringes, highlighting a critical infection control issue.

## Contribution

The study identifies contaminated blood gas syringes as the source of a Ralstonia insidiosa outbreak and confirms monoclonal transmission.

## Key findings

- Ralstonia insidiosa was isolated from blood gas syringes with matching LOT numbers, linking them to patient infections.
- AP-PCR genotyping confirmed that all isolates were monoclonal, indicating a single source of contamination.
- The outbreak was traced to contaminated syringes, leading to their recall and reporting to health authorities.

## Abstract

Ralstonia species are opportunistic, waterborne microorganisms known for their ability to survive and proliferate in a wide range of water-based environments. They can contaminate solutions used for patient care and cause hospital outbreaks due to contaminated solutions. The aim of this study was to investigate the source and clonal relationship of Ralstonia insidiosa bacteremia detected in 28 patients between August and December 2021, as part of an unusual outbreak.

Active prospective surveillance studies were conducted, and environmental samples, including saline, antiseptic, and antibiotic solutions, injectors, arterial blood gas syringes, tap water, and hand soap, were collected from wards to determine the source of the outbreak. An arbitrary-primed polymerase chain reaction (AP-PCR) genotyping method was used to determine the clonal relationship between the isolates.

All the samples were cultured, and R. insidiosa was isolated from arterial blood gas syringes with the same location and time-based identifier (LOT number). All the arterial blood gas syringes were recalled from the hospital departments and sent back to the manufacturer. The outbreak was reported to the national health authorities. Clonal analysis between isolates from the patients and the blood gas syringes was performed using AP-PCR. It was observed that the R. insidiosa isolates were monoclonal and identical.

It was concluded that these contaminated arterial blood gas syringes caused the R. insidiosa bacteremia, especially in immunocompromised patients.