Predictors for Developing a Carbapenem-Resistant Enterobacteriaceae Invasive Infection from Bacteriuria Open Access

Howard-Anderson, Jessica (Spring 2020)

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Infections with carbapenem-resistant Enterobacteriaceae (CRE) have limited treatment options and high mortality. Patients with CRE isolated only from urine (bacteriuria) have better outcomes than patients with CRE from a sterile site (invasive infection). This study describes the clinical epidemiology of CRE bacteriuria in metropolitan Atlanta and evaluates if urinary catheters increase the risk of “progression” from CRE bacteriuria to an invasive CRE infection.



We used active, laboratory- and population-based surveillance data from the Georgia Emerging Infections Program to identify patients with CRE bacteriuria in metropolitan Atlanta between 2012 - 2017.  We calculated the annual incidence of CRE bacteriuria using census data and described the clinical characteristics of this cohort through chart review. We used univariable analyses to identify risk factors associated with progression to an invasive CRE infection within one year of CRE bacteriuria and multivariable logistic regression modeling to estimate the association between urinary catheters and progression. In an exploratory aim, we assessed the relatedness between urine and sterile site isolates from the same patient with pulsed-field gel electrophoresis and whole genome sequencing. Analyses were performed in SAS 9.4. 


We identified 464 patients with CRE bacteriuria, with a yearly incidence of 1.96 cases/100,000 population.  Most patients had a urinary catheter (56%), and many resided in long term care facilities (49%), had a Charlson comorbidity index (CCI) >3 (37%), or had a decubitus ulcer (36%). 25 (6%) patients had progression. Risk factors for progression included black race, high CCI, presence of a urinary catheter, central venous catheter or another indwelling device, decubitus ulcer and having a culture obtained in an inpatient facility. In multivariable models, having a urinary catheter was associated with an increased the risk of progression (OR 4.1 95% CI 1.1 – 14.5).  Most (6, 75%) patients with available isolates had highly related urine and sterile site CRE strains.


Patients with CRE bacteriuria are chronically ill and frequently have indwelling devices. Because urinary catheters may increase the risk of progression from CRE bacteriuria to an invasive infection, future interventions should target reducing inappropriate insertion and improving early appropriate removal of urinary catheters.

Table of Contents

Introduction                                                 1 – 2

Background                                                  3 – 6

Methods                                                        7 – 14

Results                                                          15 – 17

Discussion                                                   18 – 23

References                                                   24 – 28

Tables and Figures                                     29 – 38

           Table 1                                               29

           Table 2                                               30

           Table 3                                               31

           Table 4                                               32 – 33

           Table 5                                               34

           Table 6                                               35

          Figure 1: Definitions of CRE          36

Figure 2: Annual Incidence               37

Rates of CRE Bacteriuria in

Metropolitan Atlanta, 2012-2107      

Figure 3: Differences in Time to        38

Progression from Bacteriuria

to an Invasive Infection between

Patients with Different and Highly

Related CRE Strains                       

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