Two consecutive outbreaks caused by chlorhexidine mouthwash contaminated with Burkholderia contaminans in a two-hospital tertiary care system

Abstract

Hospital outbreaks caused by Burkholderia spp. have been linked to contamination of several medical solutions and products and are frequently associated with delayed detection and high mortality. To describe the management of two consecutive Burkholderia contaminans outbreaks caused by contaminated mouthwash of different brands during the COVID-19 pandemic. This was a retrospective cohort study of all patients involved in two outbreaks caused by B.contaminans detected in 2021 and 2022. The investigation was initiated after a cluster of positive respiratory specimens, followed by retrospective and prospective case-finding. A total of 69 patients were affected, 47 in 2021 and 22 in 2022. The majority of affected patients had positive respiratory specimens (85.5%); 55.1% of cases had COVID-19, and 72.5% had multidrug-resistant organisms. Almost all (97.1%) patients required ventilation and 42.0% died. Seventeen percent of cases in the first outbreak were deemed to have been acquired by patient-to-patient transmission, whereas all of the cases in the second outbreak were infected directly from using mouthwash. The experience gained from the first outbreak and the formation of a multidisciplinary Infection Control Rapid Response Team resulted in more rapid recognition and control of the second outbreak. Multivariate analysis showed that older age, intensive care unit admission, and COVID-19 infection were independent predictors of mortality. Burkholderia outbreaks at the time of COVID-19 were associated with high mortality. Rapid detection and response by a dedicated experienced team (as in the second outbreak) can reduce mortality and prevent superimposed cross-transmission between patients.