Risk factors for the acquisition of OXA-48-producing Enterobacteriaceae in a hospital outbreak setting: a matched...

In the context of a large outbreak of OXA-48-producing Enterobacteriaceae (OXA-E) in a Dutch hospital we determined risk factors for acquisition of OXA-E.

A matched case-control study was performed in which cases (culture positive for OXA-E) were matched 1:3 to controls (culture negative for OXA-E) based on hospital ward, index date (±1 week) and time exposed in the hospital (best match). Stratified analyses were performed for patients with OXA-E producing and not producing ESBL. Potential risk factors included age, gender, surgery and ICU admission within 30 days preceding the index date, presence of comorbidities and in-hospital antibiotic treatment within 30 days preceding the index date. Data analysis was performed using multivariable conditional logistic regression with Firth correction.

In total, 73 cases were matched to 211 controls. In the multivariable conditional logistic regression model, male gender (OR 2.63, 95% CI 1.25-5.53), age (per year increase, OR 1.03, 95% CI 1.00-1.05) and use of fluoroquinolones within 30 days preceding the index date (OR 2.98, 95% CI 1.06-8.41) were risk factors for acquisition of OXA-E. In the stratified multivariable conditional logistic regression model, quinolone use was a risk factor for the acquisition of ESBL-producing OXA-E and surgery was a risk factor for the acquisition of non-ESBL-producing OXA-E.

During a large, hospital-wide OXA-E outbreak, male gender, age and previous use of fluoroquinolones were risk factors for acquisition of OXA-E. These findings may help in optimizing screening and isolation strategies in future OXA-E outbreaks.