Carbapenemase-producing Acinetobacter baumannii: An outbreak report with special highlights on economic burden.

OBJECTIVE: We aimed to describe the management of a carbapenemase-producing Acinetobacter baumannii (CP-AB) outbreak using the Outbreak Reports and Intervention Studies of Nosocomial Infection (ORION) statement. We also aimed to evaluate the cost of the outbreak and simulate costs if a dedicated unit to manage such outbreak had been set-up. METHODS: We performed a prospective epidemiological study. Multiple interventions were implemented including cohorting measures and limitation of admissions. Cost estimation was performed using administrative local data. RESULTS: Five patients were colonized with CP-AB and hospitalized in the neurosurgery ward. The index case was a patient who had been previously hospitalized in Portugal. Four secondary colonized patients were further observed within the unit. The strains of A. baumannii were shown to belong to the same clone and all of them produced an OXA-23 carbapenemase. The closure of the ward associated with the discharge of the five patients in a cohorting area of the Infectious Diseases Unit with dedicated staff put a stop to the outbreak. The estimated cost of this 17-week outbreak was $474,474. If patients had been managed in a dedicated unit - including specific area for cohorting of patients and dedicated staff - at the beginning of the outbreak, the estimated cost would have been $189,046. CONCLUSION: Controlling hospital outbreaks involving multidrug-resistant bacteria requires a rapid cohorting of patients. Using simulation, we highlighted cost gain when using a dedicated cohorting unit strategy for such an outbreak.