Nosocomial Outbreak of NDM Burkholderia: A Multidisciplinary Investigation to reveal the source

Background

Healthcare-associated infections remain a major challenge in modern medicine, related to high morbidity, prolonged hospitalitation, increased costs and mortality. Infections from contaminated pharmaceutical products are often underestimated and underdiagnosed. We describe a nosocomial outbreak by NDM-producing Burkholderia contaminans (BC) traced to contaminated pharmaceuticals and the multidisciplinary investigation undertaken.

Methods

An unexpected increase in nosocomial bloodstream infections due to BC was identified between October and November 2025. Cases were confirmed by microbiological testing for species identification and resistance genes. Outbreak investigation used the Care Scene Investigation approach, including case analysis, collection of clinical, demographic, and epidemiological data by staff interviews and medical records, implementation of standard cross-transmission control measures, and environmental sampling of surfaces, pharmaceuticals, fluid, and medical devices.

Results

Twenty-six bloodstream infection and one pleural fluid case were identified. The patients were distributed across different wards, were frail and all had cardiac disorders or hypertension (mean age 68.7 years; mean length of stay 32.56 days). A total of 254 samples were collected: 49 sponges and swabs taken from high-touch surfaces, 57 liquid solutions, 99 medical devices, and 49 medications. The results shown six of the 27 vials of intravenously metoprolol, imported from a non-European manufacturer, tested positive for BC. The drug was immediately withdrawn throughout the hospital, and regional and national health authorities notified. No further cases reported after withdrawal.

Conclusions

This outbreak highlights the critical role of pharmacovigilance, quality assurance for imported parenteral products, multidisciplinary collaboration and rapid information sharing. All of which are essential for control healthcare-associated infection clusters.

Key messages

• A multidisciplinary investigation revealed a nosocomial outbreak caused by NDM-producing Burkholderia contaminans, identifying contaminated pharmaceuticals as the source.

• The nosocomial outbreak linked to an imported drug highlights the need for pharmacovigilance, rigorous quality controls, and rapid information sharing.