Bloodstream Infections in the Elderly: Effects of Nursing Homes on Antimicrobial-Resistant Bacteria

Nursing home-associated bloodstream infection: A scoping review

OBJECTIVE

To update a 2005 review of nursing home-associated bloodstream infection (NHABSI) regarding sources, organisms, antibiotic resistance, and outcome.

METHODS

A scoping review of studies of NHABSI identified by searching Google Scholar and Medline with OVID for the period January 1, 2004, to June 30, 2021, was conducted.

RESULTS

Overall, 6 studies of NHABSI were identified. Only 1 study was conducted with residents in North American facilities whereas in the 2005 review all studies were conducted in North America. Escherichia coli was the most common blood isolate, the urinary tract was the most common source of NHABSI; and the case-fatality rates ranged from 21% to 28%. These findings were comparable to those in the 2005 review. However, the proportion of NHABSI episodes due to antibiotic-resistant organisms increased substantially compared to the 2005 review. The most common antibiotic-resistant organisms were extended-spectrum β-lactamase-producing E. coli and Klebsiella spp. The 2 studies that evaluated the relationship between appropriate empiric antibiotic therapy and outcome came to different conclusions.

CONCLUSIONS

The only major difference between the 2 reviews in the epidemiology of NHABSI was the marked increase in antibiotic resistance among blood isolates. Despite the increased antibiotic resistance, the case fatality rates in the current review were comparable to those reported in the 2005 review. However, the impact of appropriate empiric antibiotic therapy on outcome of NHABSI remains unclear.

Risk factors for Pseudomonas aeruginosa infections in Asia-Pacific and consequences of inappropriate initial antimicrobial therapy: A systematic literature review and meta-analysis

OBJECTIVES

Treating infections of Gram-negative pathogens, in particular Pseudomonas aeruginosa, is a challenge for clinicians in the Asia-Pacific region owing to inherent and acquired antimicrobial resistance. This systematic review and meta-analysis provides updated information on risk factors for P. aeruginosa infection in Asia-Pacific as well as the consequences (e.g. mortality, costs) of initial inappropriate antimicrobial therapy (IIAT).

METHODS

Embase and MEDLINE databases were searched for Asia-Pacific studies reporting the consequences of IIAT versus initial appropriate antimicrobial therapy (IAAT) in Gram-negative bacterial infections as well as risk factors for serious P. aeruginosa infection. A meta-analysis of unadjusted mortality was performed using a random-effects model.

RESULTS

A total of 22 studies reporting mortality and 13 reporting risk factors were identified. The meta-analysis demonstrated that mortality was significantly lower in patients receiving IAAT versus IIAT, with a 67% reduction observed for 28- or 30-day all-cause mortality (odds ratio=0.33, 95% confidence interval 0.20-0.55; P<0.001). Risk factors for serious P. aeruginosa infection include previous exposure to antimicrobials, mechanical ventilation and previous hospitalisation.

CONCLUSION

High rates of antimicrobial resistance in Asia-Pacific as well as the increased mortality associated with IIAT and the presence of risk factors for serious infection highlight the importance of access to newer and appropriate antimicrobials.

Prevalence and risk factors for bloodstream infection present on hospital admission

Background

Bloodstream infection present on hospital admission (BSI-POA) is a major cause of morbidity and mortality. The purpose of this study was to measure prevalence and describe the risk factors of patients with BSI-POA and to determine the prevalence of resistance in isolates by admission source.

Methods

We conducted a retrospective cohort study of patients discharged from three hospitals in New York City between 2006 and 2014. BSI-POA was defined as BSI diagnosed within 48 h of hospitalisation.

Results

The prevalence for BSI-POA was 5307/315,010 discharges (1.7%). The odds of being admitted with BSI-POA were greatest among patients admitted with renal failure, chronic dermatitis, malignancies and prior hospitalisation. Odds ratios and 95% confidence intervals (CI) were 2.72 (95% CI = 2.56-2.88), 2.15 (95% CI = 1.97-2.34), 1.76 (95% CI = 1.64-1.88) and 1.59 (95% CI = 1.50-1.69), respectively. The largest proportion of BSI-POA presented with Staphylococcus aureus (48.4%), followed by Enterococcus faecalis/faecium (20.3%), Klebsiella pneumoniae (16.2%), Streptococcus pneumoniae (8.7%), Pseudomonas aeruginosa (4.2%) and Acinetobacter baumannii (2.2%). Overall, 44% of those admitted from nursing homes presented with antibiotic resistant strains versus 34% from other hospitals and 31% from private homes (P = 0.002).

Conclusion

Understanding the risk factors of patients who present to the hospital with BSI could enable timely interventions and better patient outcomes.