Outbreak of Burkholderia cepacia in an intensive care unit: temporal trend, clinical characteristics and outcomes of patients

Burkholderia cepacia, an environmental microorganism which can be an opportunistic pathogen in patients with cystic fibrosis, is emerging as a causative agent of nosocomial outbreaks involving bloodstream,respiratory tract, and urinary tract infections in intensive care unit (ICU) settings. An outbreak of B.cepacia has recently occurred in ICU at the teaching hospital in Modena (northern Italy). A sudden increaseof B. cepacia positive cultures has been highlighted thank to the alert organisms laboratory surveillance activities routinely performed at the structure. The outbreak lasted 18 months and involved 46 patients(25 males and 21 females, mean age 63±18years): 63% of the subjects were colonized and 37% developed an infection (respiratory tract infection). The analysis of spatial and temporal trends of cases together with different environmental investigations and the genotyping of the isolated microorganisms allowed to identify and to remove the source of the outbreak, a contaminated mouthwash for oral hygiene of patients, determining the rapid resolution of the outbreak. A descriptive epidemiological survey of cases has been performed as well, in order to investigate the relationship between host, pathogen and environment and to identify potential predictors to clinical response. Characteristics of infected and colonized patients were compared: no significant differences were found as thetwo groups showed very really similar demographic and clinical conditions and outcomes (mortality rate: 50% in both groups). Severity of the underlying disease resulted the main factor influencing mortality risk, however it did not appear to be related to thecolonized or infected status of patients.