Risk factors for bloodstream infections caused by extended-spectrum β-lactamase-producing Escherichia coli and Klebsiella pneumoniae

Bacteremia Caused by Extended-Spectrum Beta-Lactamase-Producing Enterobacteriaceae in Vientiane, Lao PDR: A 5-Year Study

Although there has been an increasing incidence of bacteremia caused by extended-spectrum beta-lactamase (ESBL)-producing Enterobacteriaceae (ESBL-E) across South East Asia, there are sparse data from the Lao PDR, where laboratory capacity for antimicrobial resistance surveillance is limited. We, therefore, retrospectively reviewed bacteremia caused by ESBL-producing Escherichia coli and Klebsiella pneumoniae between 2010 and 2014 at Mahosot Hospital, Vientiane, Lao PDR. Clinical and laboratory data relating to all episodes of ESBL-E bacteremia were reviewed over the 5-year period and compared with non-ESBL-E bacteremia. Blood cultures positive for E. coli or K. pneumoniae were identified retrospectively from laboratory records. Clinical and laboratory data were extracted from research databases and case notes and analyzed using STATA. Between 2010 and 2014, we identified 360 patients with E. coli (n = 249) or K. pneumoniae (n = 111) bacteremia, representing 34.8% of all patients with clinically significant bacteremia. Seventy-two (20%) isolates produced ESBL; E. coli accounted for 15.3% (55/360) and K. pneumoniae for 4.7% (17/360), respectively. The incidence of ESBL-producing E. coli bacteremia rose during the study period. By multiple logistic analysis, reported antibiotic use in the previous week was significantly associated with ESBL positivity (P < 0.001, odds ratio 3.89). Although multiresistant, most ESBL-producing E. coli and K. pneumoniae remained susceptible to meropenem (65/65; 100%) and amikacin (64/65; 98.5%). We demonstrated an alarming increase in the incidence of ESBL-E as a cause of bacteremia in Vientiane during the study period. This has implications for empiric therapy of sepsis in Laos, and ongoing surveillance is essential.

Urosepsis Due to Extended-Spectrum β-Lactamase-Producing Escherichia coli: A Retrospective, Single-Centre Review of Risk Factors and Clinical Outcomes

BACKGROUND

Extended-spectrum β-lactamase (ESBL)-producing Enterobacteriaceae are pathogens that are implicated in urosepsis and may be associated with greater morbidity and mortality than non-ESBL Enterobacteriaceae. Identification of risk factors for ESBL infection may facilitate the selection of appropriate empiric therapy.

OBJECTIVES

The primary objectives were to determine the cumulative incidence of ESBL urosepsis, to identify major risk factors for ESBL urosepsis, and to determine the impact of international travel on development of ESBL urosepsis in an ethnically diverse Canadian population. The secondary objective was to characterize the outcomes of patients with ESBL urosepsis.

METHODS

A single-centre retrospective nested case-control study was conducted from January 2011 to June 2013. The study cohort consisted of adult patients with urosepsis and positive results on blood culture for ESBL-producing and non-ESBL-producing Enterobacteriaceae. Multivariate analysis was then used to determine risk factors for ESBL urosepsis.

RESULTS

The cumulative incidence of ESBL urosepsis at the study site was 19.4% (58/299) over 2.5 years. The 58 cases of ESBL urosepsis were compared with 118 controls (patients with urosepsis caused by non-ESBL Enterobacteriaceae). Significant predictors of ESBL urosepsis were chronic renal insufficiency (odds ratio [OR] 4.66, 95% confidence interval [CI] 1.96-11.08; p < 0.001) and travel to an endemic region in the previous 6 months (OR 4.62, 95% CI 1.17-18.19; p = 0.029), as well as Punjabi or Hindi as the primary language (OR 3.25, 95% CI 1.45-7.29; p = 0.004) and male sex (OR 2.65, 95% CI 1.21-5.80; p = 0.015). Patients with ESBL urosepsis had worse prognosis-in terms of death or discharge with palliative measures only-than those with non-ESBL urosepsis (7/58 [12.1%] versus 4/118 [3.4%]; p = 0.042).

CONCLUSIONS

Institution-specific data support prompt recognition of patients at risk for ESBL infections. Chronic renal insufficiency, recent travel to regions endemic for ESBL-producing organisms, primary language of Punjabi or Hindi, and male sex were the strongest risk factors for ESBL urosepsis at the study centre. However, findings from this single-centre study may not be generalizable to other institutions.