Risk factors associated with the development of multidrug-resistant bloodstream infection in patients with...

To examine the risk factors associated with the development of multidrug-resistant organism (MDRO) bloodstream infection (BSI) in hospitalized adult patients with previous MDRO colonization or isolation from clinical samples.

This retrospective, matched case-control study compared patients with previous MDRO colonization or isolation from clinical samples who developed BSI with patients with the same MDRO species who did not develop BSI. Factors associated with the progression from previous MDRO isolation to BSI were examined using conditional logistic regression, stratified by the matched set. Matching was performed at 1:2 according to age and sex.

A total of 1269 non-repeat previous MDRO isolation events were identified in 961 patients. A total of 12.9% of patients had two or more MDROs isolates. Overall, 172 (13.5%) non-repeat BSI events occurred in patients with MDRO colonization/infection, of which 78 (45.4%) were caused by the same MDRO species. A total of 6.1% of previous MDRO isolation events progressed to BSI caused by the same MDRO species. Previous admission to the intensive care unit (adjusted odds ratio 4.31; 95% confidence interval 1.44-12.96; P = 0.009) and presence of a central venous catheter (adjusted odds ratio 3.38; 95% confidence interval 1.55-7.39; P = 0.002) were independent risk factors associated with the development of BSI caused by the same MDRO species.

Recent intensive care unit admission and central venous catheterization are independently associated with progression from previous MDRO isolation to BSI.