Burkholderia cepacia complex bacteremia: an outbreak investigation with epidemiological link to contaminated disinfectant

Objective: To describe an outbreak of Burkholderia cepacia complex at a tertiary care hospital in Karachi, Pakistan, highlighting contributing factors, potential sources, and system-level gaps identified during the investigation. Design: Outbreak investigation. Setting: A 655-bed tertiary care teaching hospital in Karachi, Pakistan. Participants: All individuals who had positive blood cultures by non-lactose fermenting, oxidase-positive, Gram-negative rods that could not be further characterized. Methods: On September 26, 2020, the Department of Infection Prevention and Hospital Epidemiology (DIPHE) was notified of multiple positive blood cultures. An outbreak investigation was initiated, including chart reviews, laboratory analysis, environmental sampling, assessing central line insertion practices, and evaluating the manufacturing site. Clinical Laboratory Standards Institute (CLSI) guidelines were used for microbiological identification and susceptibility testing. Results: Thirty-five patients with positive cultures were identified between September 15 and October 22, 2020. While environmental sampling did not yield growth, significant breaches at the suppliers‘ facility were identified in chlorhexidine gluconate (CHG) storage and quality control. Although cultures of CHG were negative, the product’s withdrawal led to a marked decline in new cases. Moreover, while resources were unavailable for genomic testing, antimicrobial susceptibility patterns were similar in all the case strains, suggesting a common source. Conclusion: This outbreak highlights the role of contaminated disinfectants in healthcare-associated infections. It also revealed systemic gaps in disinfectant quality control, storage facilities, and diagnostic capacity, delaying outbreak recognition and response. It is essential to strengthen regulatory oversight, implement standardized testing protocols, and enhance microbiological diagnostic infrastructure to lower the risk of similar outbreaks.