The impact of ageing on the incidence and mortality rate of bloodstream infection: A hospital-based case-cohort study in a tertiary public hospital of Brazil

Assessing the burden of disease of gram-negative bloodstream infections in a Brazilian hospital: A retrospective cohort study from 2015 to 2019

Objectives

This study aimed to estimate the disease burden of BSIs caused by gram-negative bacteria (GNB-BSIs) in a Brazilian hospital from 2015 to 2019, measured in disability-adjusted life-years (DALYs).

Methods

A retrospective cohort study of adult patients with GNB-BSI was conducted from April 01, 2015 to March 31, 2019. This study was carried out in a 356-bed private hospital with a 68-bed medical intensive care unit located in Salvador, Brazil. Demographic and clinical data were collected through a review of medical records. DALYs were estimated using Monte Carlo Simulations, using life tables for Brazilians estimated for 2020 and the Global Burden of Diseases 2010 (GBD 2010).

Results

A total of 519 GNB-BSI episodes in 498 individuals were identified. The mean age was 59.92 ± 17.97 years, with 61.1% being male. The most common bacterial infections were Klebsiella pneumoniae and Escherichia coli (66.5%), whereas carbapenem-resistant gram-negative bacteria (CR-GNB) accounted for 32.7% of cases. The highest overall DALYs were observed in 2018 (752, 95% confidence interval [CI]: 520-1021 with Brazilian Life Tables and 782, 95% CI: 540-1062 with GBD 2010). Infections due to CR-GNB had the highest DALYs, particularly, in 2017, reaching 7050 (95% CI: 3200-12,150 with Brazilian Life Tables and 7350, 95% CI: 3350-12,700 with GBD 2010) DALYs per 1000 patient days and an estimated mortality rate of 40% per 1000 patient days.

Conclusions

The persistently high DALYs associated with CR-GNB raise alarming concerns, potentially leading to over 300 deaths per 1000 patient days in the coming years. These findings underscore the urgency of addressing GNB-BSI as a significant public health issue in Brazil. These results are expected to provide helpful information for public health policymakers to prioritize interventions for infections due to antibiotic-resistant bacteria.

Relationship of C-reactive Protein/Serum Albumin Ratio and qPitt Bacteremia Score With An All-Cause In-Hospital Mortality in Patients With Bloodstream Infections

BACKGROUND

Bloodstream infections remain a major cause of morbidity and mortality despite notable advances in their diagnosis and treatment. C-reactive protein/serum albumin ratio and the quick Pitt bacteremia score are two useful tools for clinicians to assess severity and predict mortality risk in patients with sepsis attributable to bloodstream infections. This study examined the relationship between C-reactive protein/serum albumin ratio and Q Pitt bacteremia score with all-cause in-hospital mortality in patients with bloodstream infections.

METHODS

Hospitalized adult patients with bacteremic bloodstream infections between January 1, 2020, and December 31, 2021, were retrospectively reviewed. Patients' demographics and clinical and laboratory data were retrieved from patient electronic records. C-reactive protein/albumin ratio was calculated using CRP (mg/L) and serum albumin (g/L) values obtained within 24 hours of blood culture collection and quick Pitt bacteremia score was calculated for each patient with each of the five variables of the score determined within 24 hours of blood culture collection and each patient was assigned a numerical score of 0-5 accordingly. The relationship between C-reactive protein/albumin ratio and quick Pitt bacteremia score with all-cause in-hospital mortality was determined.

RESULTS

A total of 187 hospitalized adult patients with non-repeat bacteremic bloodstream infections were identified. Escherichia coli was the most common Gram-negative blood isolate while Staphylococcus aureus was the predominant Gram-positive isolate. One hundred and five (56.1%) patients were male with a cohort mean age of 56.9 ± 2.7 years. All-cause in-hospital mortality was 27.3%. The mean CRP/albumin ratio (8.6 ±1.7) and mean quick Pitt bacteremia score (2.8 ±0.4) were significantly higher in patients with bloodstream infections who died during their hospitalization compared to those who survived. The all-cause in-hospital mortality was 8%, 12%, 22%, 46%, 93%, and 100% for patients with quick Pitt scores of 0, 1, 2, 3, 4, and 5, respectively.

CONCLUSION

In hospitalized patients with bacteremic bloodstream infections, an incremental increase in quick Pitt bacteremia score and mean C-reactive protein/albumin ratio of >8 was associated with higher mortality.

Species Distribution, Typical Clinical Features and Risk Factors for Poor Prognosis of Super-Elderly Patients with Bloodstream Infection in China

Objective

Bloodstream infection (BSI) is characterized by high mortality, especially among these increasing super-elderly patients (≥85 years), and this study was conducted to understand the species distribution, typical clinical features and risk factors for poor prognosis of super-elderly patients with BSI.

Methods

Based on previous work, this retrospective study was performed by reviewing an ongoing prospective medical database in a comprehensive tertiary center in China, and all super-elderly patients with BSI in the past 6 years were enrolled in this study.

Results

Out of 5944 adult-patients with BSI, there were totally 431 super-elderly patients (≥85 years old) enrolled in this study and age ≥90 years accounted for 31.1% (134/431). Among these 431 super-elderly patients with BSI, 40 patients (9.3%) were diagnosed with BSI and the remained 401 super-elderly patients (90.7%) were defined as hospital-acquired BSI. The typical feature of these super-elderly patients with BSI was the high proportion of patients with various comorbidities, such as cardiovascular disease (83.8%), ischemic cerebrovascular disease (63.3%) and pulmonary infection (61.0%). The other typical feature was that most (60.1%) of these patients had been hospitalized for long time (≥28 days) prior to the onset of BSI, and most patients had received various invasive treatments, such as indwelling central venous catheter (53.1%) and indwelling urinary catheter (47.1%). Unfortunately, due to these adverse features above, both the 7-day short-term mortality (13.2%, 57/431) and the 30-day long-term mortality (24.8%, 107/431) were high. The multivariate analysis showed that both chronic liver failure (OR 7.9, 95% CI 2.3-27.8, P=0.001) and indwelling urinary catheter (OR 2.3, 95% CI 1.1-4.7, P=0.023) were independent risk factors for 7-day short-term mortality, but not for 30-day long-term mortality. In addition, the microbiology results showed that the most common species were associated with nosocomial infection or self-opportunistic infection, such as Staphylococcus hominis (18.3%), Staphylococcus epidermidis (11.8%), Escherichia coli (9.7%), Klebsiella pneumoniae (9.3%) and Candida albicans (8.6%, fungi).

Conclusion

Super-elderly patients with BSI had typical features, regardless of the pathogenic species distribution and their drug resistance, or clinical features and their risk factors for poor prognosis. These typical features deserved attention and could be used for the prevention and treatment of BSI among super-elderly patients.

Pandemic clone USA300 in a Brazilian hospital: detection of an emergent lineage among methicillin-resistant Staphylococcus aureus isolates from bloodstream infections

Background

Staphylococcus aureus is one of the leading causes of bloodstream infections (BSI) worldwide. In Brazil, the hospital-acquired methicillin-resistant S. aureus USA100/SCCmecII lineage replaced the previously well-established clones. However, the emergence of community-associated (CA) MRSA lineages among hospitalized patients is an increasing issue.

Methods

Consecutive S. aureus isolates recovered from BSI episodes of patients admitted between January 2016 and December 2018 in a Brazilian teaching hospital were tested for antimicrobial resistance, their genotypic features were characterized, and the clinical characteristics of the patients were evaluated.

Results

A total of 123 S. aureus isolates were recovered from 113 patients. All isolates were susceptible to linezolid, teicoplanin and vancomycin and 13.8% were not susceptible to daptomycin. Vancomycin MIC50 and MIC90 of 2 mg/L were found for both MRSA and MSSA isolates. The MRSA isolation rate was 30.1% (37/123), and 51.4% of them carried the SCCmec type II, followed by SCCmecIV (40.5%). Among the 37 MRSA isolates, the main lineages found were USA100/SCCmecII/ST5 and ST105 (53.7%) and USA800/ST5/SCCmecIV (18.9%). Surprisingly, six (16%) CA-MRSA isolates, belonging to USA300/ST8/SCCmecIVa that carried PVL genes and the ACME cassette type I, were detected. These six patients with USA300 BSI had severe comorbidities, including cancer, and most had a Charlson score ≥ 5; furthermore, they were in wards attended by the same health professionals. MRSA isolates were associated with hospital acquired infections (p = 0.02) in more elderly patients (p = 0.03) and those diagnosed with hematologic cancer (p = 0.04). Among patients diagnosed with MRSA BSI, 19 (54.3%) died.

Conclusions

The pandemic MRSA USA300 was detected for the first time in the Brazilian teaching hospital under study, and its cross-transmission most probably occurred between patients with BSI. This lineage may already be circulating among other Brazilian hospitals, which highlights the importance of carrying out surveillance programs to fight multidrug resistant and hypervirulent isolates.

Bacteriological Profile and Antimicrobial Susceptibility Patterns of Gram-Negative Bloodstream Infection and Risk Factors Associated with Mortality and Drug Resistance: A Retrospective Study from Shanxi, China

Objective

The aim of this study was to analyze the epidemiological of gram-negative bloodstream infection (GNBSI) and establish a risk prediction model for mortality and acquiring multidrug resistant (MDR), the extended spectrum beta-lactamases (ESBLs) producing and carbapenem-resistant (CR) GNBSI.

Methods

This retrospective study covered five years from January 2015 to December 2019. Data were obtained from Hospital Information System (HIS) and microbiology department records. The risk factors for mortality and acquiring MDR, ESBLs-producing and CR GNBSI were analyzed by univariable and multivariable analysis.

Results

A total of 1018 GNBSI cases were collected. A majority of GNBSI patients were in hematology ward (23.77%). There were 38.61% patients who were assigned in the 41–60 age group. Escherichia coli was the most common gram-negative organism (49.90%). Among isolates of GNBSI, 40.47% were found to be MDR strains, 34.09% were found to be ESBLs-producing strains and 7.06% were found to be CR strains. Escherichia coli was the most common MDR (71.36%) and ESBLs-producing strain (77.81%). Acinetobacter baumannii was the most common CR isolate (46.15%). Multivariate analysis indicated that diabetes mellitus, solid organ tumor, non-fermentative bacteria, MDR strain, central venous cannula, urinary catheter, therapy with carbapenems or tigecycline prior 30 days of infection were independent mortality risk factors for GNBSIs. Over all, therapy with tigecycline prior 30 days of infection was the mutual predictor for mortality of GNBSI, acquiring MDR, ESBLs-producing and CR GNBSI (OR, 8.221, OR, 3.963, OR, 3.588, OR, 9.222, respectively, all p < 0.001).

Conclusion

Collectively, our study implies that patients who were diagnosed as GNBSI had a younger age. Therapy with tigecycline was the mutual and paramount predictor for mortality of GNBSI, acquiring MDR, ESBLs-producing and CR GNBSI. Our investigation had provided a theoretical basis for the use of antibiotics and prevention and control of hospital infection in our region.

Carbapenem Resistant Pseudomonas aeruginosa Infections in Elderly Patients: Antimicrobial Resistance Profiles, Risk Factors and Impact on Clinical Outcomes

Objective

The prevalence and clinical impact on mortality of carbapenem-resistant Pseudomonas aeruginosa (CRPA) infection are unclear in elderly patients. Here, we aimed to clarify the prevalence, the clinical manifestations, antimicrobial resistance, risk factors and outcomes of elderly inpatients with CRPA infection.

Methods

A retrospective study of 600 elderly inpatients infected with P. aeruginosa was conducted at Yueyang Hospital of Integrated Traditional Chinese and Western Medicine from January 1st 2018 to December 31st 2020. All 155 patients with CRPA infection were designated as a case group. Patients with carbapenem-susceptible Pseudomonas aeruginosa (CSPA) were randomly selected from remaining 445 cases in a 1:1 ratio to case group as a control group.

Results

Of 600 P. aeruginosa isolates, the overall rates of CRPA, MDR PA (multidrug-resistance Pseudomonas aeruginosa) were 25.8% (155), 22.3% (134), respectively. The rankings of the top five resistant rates of CRPA to tested antimicrobial drugs were imipenem (87.7%), meropenem (70.3%), ciprofloxacin (51.0%), levofloxacin (48.4%), cefoperazone (43.2%). Independent risk factors for patients with CRPA infection were cerebrovascular disease (OR = 3.517, P < 0.001), foley catheter (OR = 2.073, P = 0.018), length of hospital stay ≥ 14 days (OR = 1.980, P = 0.013), albumin < 35 g/L (OR = 2.049, P = 0.020), previous antibiotic exposure to carbapenems (OR = 7.022, P = 0.004), previous antibiotic exposure to third- or fourth-generation cephalosporins (OR = 12.649, P = 0.002). Of 155 patients with CRPA infection, the mortality rate was 16.8% (26/155). Independent risk factors for mortality were receiving mechanical ventilation (OR = 3.671, P = 0.007) and neutrophil percentage ≥ 80% (OR = 2.908, P = 0.024).

Conclusion

The study revealed high rates of CRPA, MDR PA among the hospitalized elderly patient with P. aeruginosa infection. The analysis of antimicrobial susceptibility emphasizes the necessity for antimicrobial stewardship and infection control in hospitals. These findings of risk factors are practical significant to identify patients at high risk for CRPA infection and mortality that may benefit from alternate empiric treatment.