Community-associated Bloodstream Infections Research Articles

Factors associated with foreign body infection in methicillin-resistant Staphylococcus aureus bacteremia.

We aimed to compare patient characteristics, MRSA sequence types, and biofilm production of MRSA strains that did and did not cause a foreign body infection in patients with MRSA bloodstream infections (BSI). All adult patients with MRSA BSI hospitalized in two hospitals were identified by clinical microbiology laboratory surveillance. Only patients who had at least one implanted foreign body during the episode of BSI were included. In July 2018 - March 2022, of 423 patients identified with MRSA BSI, 118 (28%) had ≥1 foreign body. Among them, 51 (43%) had one or more foreign body infections. In multivariable analysis, factors associated with foreign body infection were history of MRSA infection in the last year (OR=4.7 [1.4-15.5], p=0.012) community-associated BSI (OR=68.1 [4.2-1114.3], p=0.003); surgical site infection as source of infection (OR=11.8 [2-70.4], p=0.007); presence of more than one foreign body (OR=3.4 [1.1-10.7], p=0.033); interval between foreign body implantation and infection <18 months (OR=3.3 [1.1-10], p=0.031); and positive blood culture ≥48h (OR=16.7 [4.3-65.7], p<0.001). The most prevalent sequence type was ST8 (39%), followed by ST5 (29%), and ST105 (20%) with no significant difference between patients with or without foreign body infection. Only 39% of MRSA isolates formed a moderate/strong biofilm. No significant difference was observed between patients with foreign body infection and those without foreign body infection. In multivariable analysis, subjects infected with a MRSA isolate producing moderate/strong in vitro biofilm were more likely to have a history of MRSA infection in the last year (OR=3.41 [1.23-9.43]), interval between foreign body implantation and MRSA BSI <18 months (OR=3.1 [1.05-9.2]) and ST8 (OR=10.64 [2-57.3]). Most factors associated with foreign body infection in MRSA BSI were also characteristic of persistent infections. Biofilm-forming isolates were not associated with a higher risk of foreign-body infection but appeared to be associated with MRSA genetic lineage, especially ST8.

Epidemiology and Risk Factors of Community-Associated Bloodstream Infections in Zhejiang Province, China, 2017-2020.

Community-associated bloodstream infection (CA-BSI) is increasing in many community settings. However, the clinical significance and epidemiology of CA-BSI present in hospital admissions in China are not well established. In this work, we identified the risk factors in outpatients presenting with CA-BSI, and investigate the role of procalcitonin (PCT) and hypersensitive C-reactive protein (CRP) in diagnosing different types of the pathogen in patients with acute CA-BSI. A retrospective study enrolling 219 outpatients with CA-BSI from The Zhejiang People's Hospital from January 2017 to December 2020 was performed. Susceptibility of the isolates obtained from these patients was examined. Subjecting receiver operating characteristic curves (ROC) were constructed to analyze the specificity and sensitivity of PCT, CRP, and WBC in determining infections caused by different bacterial genera. Risk factors for CA-BSI in the emergency setting were analyzed using essential information and simple identification of other pathogenic bacterial species through rapidly tested biomarkers. A total of 219 patients were included in the selection criteria, of which 103 were infected with Gram-positive bacteria (G+) and 116 with Gram-negative bacteria (G-). The PCT was significantly higher in the GN-BSI group than in the GP-BSI group, while no significant difference was observed between the two groups for CRP. Subjecting ROC curves were constructed to analyze WBC, CRP, and PCT, and the area under the curve (AUC) of the PCT in this model was 0.6661, with sensitivity = 0.798 and specificity = 0.489. The PCT between the GP-BSI group and the GN-BSI group was significantly different. By combining the knowledge of clinicians and the clinical signs of patients, PCT should be utilized as a supplementary approach to initially determine pathogens and direct medication in the early stages of clinical practice.

Antimicrobial susceptibility to polymyxin B and other comparators against Gram-negative bacteria isolated from bloodstream infections in China: Results from CARVIS-NET program.

ObjectiveTo investigate the bacterial distribution and antimicrobial resistance profile of clinical isolates from Gram-negative bacteria bloodstream infections (GNBSI) in China.MethodsThe clinical bacterial strains isolated from blood culture were collected during April 2019 to December 2021 in 21 member hospitals of China Bloodstream Gram-negative Pathogens Antimicrobial Resistance and Virulence Surveillance Network (CARVIS-NET). Antibiotic susceptibility test was conducted by broth microdilution method recommended by Clinical and Laboratory Standards Institute (CLSI, United States). WHONET 2021 and SPSS 22.0 were used to analyze data.ResultsDuring the study period, 1939 Gram-negative bacteria were collected from 21 hospitals, among which 1,724 (88.9%) were Enterobacteriaceae, 207 (10.7%) were non-fermenting Gram-negative bacteria and 8 (0.4%) were others. The top five bacterial species were Escherichia coli (46.2%), Klebsiella pneumoniae (31.6%), Pseudomonas aeruginosa (4.9%), Acinetobacter baumannii (4.2%) and Enterobacter cloacae (3.0%). For K. pneumoniae, antibiotic resistance was mainly prevalent in hospital-associated bloodstream infections, while for A. baumannii, antibiotic resistance was mainly prevalent in community-associated bloodstream infections. It is worth mentioning that 94.1% of the 1939 Gram-negative isolates were susceptible to polymyxin B. The sensitivity of the strains involved in our investigation to polymyxin B is highly correlated with their sensitivity to colistin.ConclusionThe surveillance results in CARVIS-NET-2021 showed that the main pathogens of GNBSI in China were Enterobacteriaceae, while E. coli was the most common pathogen. The resistance rates of K. pneumonia, P. aeruginosa, A. baumannii, and E. cloacae to multiple antibiotics kept on a high level. In many cases, polymyxin B and colistin has become the last-resort agents to combat bloodstream infections caused by multidrug-resistant (MDR) Gram-negative bacteria.

559. Two Different Beasts: Comparing Epidemiology of Healthcare-Associated vs. Community-Acquired Methicillin-Resistant Staphylococcus aureus Bacteremia

BackgroundMethicillin-resistant staphylococcus aureus (MRSA) bloodstream infection (BSI) is associated with significant morbidity and mortality. Healthcare-associated (HCA) MRSA infection (occurring >48 hours after hospitalization or in those with prior healthcare exposure) has traditionally been associated with severe invasive disease, while community-associated (CA) MRSA infection (occurring within 48 hours of hospitalization and without prior healthcare exposure) has been observed in otherwise healthy individuals. We characterized the epidemiology, resistance patterns, and clinical outcomes associated with MRSA BSI over a 5 year period comparing patients with community-onset bacteremia to those with hospital onset bacteremia.MethodsWe performed a retrospective chart review of 151 MRSA bloodstream infections from 2013–2018 at the University of Alberta Hospital (Edmonton, Canada). We assessed each BSI by: classification (CA vs. HCA), presence of MRSA risk factors, source of infection, MRSA resistance, rate of ICU admission, and 30-day mortality.ResultsThe median age of all patients with MRSA BSI was 53 years (range 23–94). MRSA BSI occurred more commonly in males for both CA and HCA infection (53% and 62%). HCA-MRSA infections had a higher rate of previous MRSA colonization (64.8%) compared with CA-MRSA patients (41.7%). Injection drug use was higher in CA-MRSA infections (47% vs. 11%). The most common source of CA-BSI was bone/joint (30%) while line-associated infections were the most common in HCA-BSI. Clindamycin resistance was common (46–53% susceptible) while resistance to tetracyclines (91–97% susceptible) and trimethoprim/sulfamethoxazole (98–100% susceptible) was uncommon. HCA-MRSA BSI was associated with a higher rate of ICU admission (44% vs. 33%) and 30-day mortality (18.7% vs. 11.7%).ConclusionInvasive MRSA infection continues to be associated with significant morbidity and mortality. We found that healthcare-associated MRSA BSI was associated with a high rate of prior MRSA colonization as well as a higher rate of ICU admission and 30-day mortality. There are significant differences in the demographics of patients with CA BSI compared with HCA BSI. Interventions to prevent these infections need to be targeted to the geographic location of acquisition.Disclosures All authors: No reported disclosures.

Trends in Incidence of Methicillin-resistant Staphylococcus aureus Bloodstream Infections Differ by Strain Type and Healthcare Exposure, United States, 2005-2013.

Previous reports suggested that US methicillin-resistant Staphylococcus aureus (MRSA) strain epidemiology has changed since the rise of USA300 MRSA. We describe invasive MRSA trends by strain type. Data came from 5 Centers for Disease Control and Prevention Emerging Infections Program sites conducting population-based surveillance and collecting isolates for invasive MRSA (ie, from normally sterile body sites), 2005-2013. MRSA bloodstream infection (BSI) incidence per 100 000 population was stratified by strain type and epidemiologic classification of healthcare exposures. Invasive USA100 vs USA300 case characteristics from 2013 were compared through logistic regression. From 2005 to 2013, USA100 incidence decreased most notably for hospital-onset (6.1 vs 0.9/100 000 persons, P < .0001) and healthcare-associated, community-onset (10.7 vs 4.9/100 000 persons, P < .0001) BSIs. USA300 incidence for hospital-onset BSIs also decreased (1.5 vs 0.6/100 000 persons, P < .0001). However, USA300 incidence did not significantly change for healthcare-associated, community-onset (3.9 vs 3.3/100 000 persons, P = .05) or community-associated BSIs (2.5 vs 2.4/100 000 persons, P = .19). Invasive MRSA was less likely to be USA300 in patients who were older (adjusted odds ratio [aOR], 0.97 per year [95% confidence interval {CI}, .96-.98]), previously hospitalized (aOR, 0.36 [95% CI, .24-.54]), or had central lines (aOR, 0.44 [95% CI, .27-.74]), and associated with USA300 in people who inject drugs (aOR, 4.58 [95% CI, 1.16-17.95]). Most of the decline in MRSA BSIs was from decreases in USA100 BSI incidence. Prevention of USA300 MRSA BSIs in the community will be needed to further reduce burden from MRSA BSIs.

Prevalence and risk factors for antibiotic-resistant community-associated bloodstream infections

Antibiotic resistance is increasing in many community settings. The purpose of this study was to determine the proportion of antibiotic resistant community-associated bloodstream infections (CA-BSIs) present on hospital admissions to identify risk factors for acquiring resistant versus susceptible CA-BSIs and to describe the incidence of concurrent infections with CA-BSIs. We conducted a retrospective cohort study of patients discharged from one community, one pediatric, and two tertiary/quaternary care hospitals within an academically affiliated network in the borough of Manhattan in New York, NY, from 2006 to 2008. The CA-BSIs present at hospital admission were defined as BSIs occurring within the first 48h of hospitalization. Infections and patient characteristics were identified using data available from patients' electronic medical records and discharge records. In total, 1677 CA-BSIs were identified. Staphylococcus aureus had the largest proportion of resistance (41.2%), followed by enterococcal species (24.3%), Pseudomonas aeruginosa (20.2%), Streptococcus pneumoniae (16.6%), Acinetobacter baumannii (10.0%), and Klebsiella pneumoniae (9.9%). Significant predictors of resistance were prior residence in a skilled nursing facility (OR, 2.55; 95% CI, 1.39-4.70), advanced age (1.01; 1.002-1.02), presence of malignancy (0.58; 0.37-0.91), prior hospitalization (1.62; 1.17-2.23), a weighted Charlson score (1.09; 1.02-1.17) for S. aureus, presence of malignancy (1.82; 1.004-3.30), prior hospitalizations (2.03; 1.12-3.38) for enterococcal species, and younger age for S. pneumoniae (p=0.02). Urinary tract infections were the most common concurrent infection (n=45/87, 51.7%). Over 27% of the CA-BSIs present on admission were antibiotic resistant. Understanding the prevalence and risk factors for CA-BSIs may help improve empiric antibiotic therapy and outcomes for patients with community-onset infections.

Gender Differences in Risk of Bloodstream and Surgical Site Infections

Identifying patients most at risk for hospital- and community-associated infections is one essential strategy for preventing infections. To investigate whether rates of community- and healthcare-associated bloodstream and surgical site infections varied by patient gender in a large cohort after controlling for a wide variety of possible confounders. Retrospective cohort study. All patients discharged from January 1, 2006 through December 31, 2008 (133,756 adult discharges and 66,592 pediatric discharges) from a 650-bed tertiary care hospital, a 220-bed community hospital, and a 280-bed pediatric acute care hospital within a large, academic medical center in New York, NY. Data were collected retrospectively from various electronic sources shared by the hospitals and linked using patients' unique medical record numbers. Infections were identified using previously validated computerized algorithms. Odds of community-associated bloodstream infections, healthcare-associated bloodstream infections, and surgical site infections were significantly lower for women than for men after controlling for present-on-admission patient characteristics and events during the hospital stay [odds ratios (95 % confidence intervals) were 0.85 (0.77-0.93), 0.82 (0.74-0.91), and 0.78 (0.68-0.91), respectively]. Gender differences were greatest for older adolescents (12-17 years) and adults 18-49 years and least for young children (<12 years) and older adults (≥ 70 years). In this cohort, men were at higher risk for bloodstream and surgical site infections, possibly due to differences in propensity for skin colonization or other anatomical differences.

Costs of Healthcare- and Community-Associated Infections With Antimicrobial-Resistant Versus Antimicrobial-Susceptible Organisms

We compared differences in the hospital charges, length of hospital stay, and mortality between patients with healthcare- and community-associated bloodstream infections, urinary tract infections, and pneumonia due to antimicrobial-resistant versus -susceptible bacterial strains. A retrospective analysis of an electronic database compiled from laboratory, pharmacy, surgery, financial, and patient location and device utilization sources was undertaken on 5699 inpatients who developed healthcare- or community-associated infections between 2006 and 2008 from 4 hospitals (1 community, 1 pediatric, 2 tertiary/quaternary care) in Manhattan. The main outcome measures were hospital charges, length of stay, and mortality among patients with antimicrobial-resistant and -susceptible infections caused by Staphylococcus aureus, Enterococcus faecium, Enterococcus faecalis, Klebsiella pneumoniae, Pseudomonas aeruginosa, and Acinetobacter baumannii. Controlling for multiple confounders using linear regression and nearest neighbor matching based on propensity score estimates, resistant healthcare- and community-associated infections, when compared with susceptible strains of the same organism, were associated with significantly higher charges ($15,626; confidence interval [CI], $4339-$26,913 and $25,573; CI, $9331-$41,816, respectively) and longer hospital stays for community-associated infections (3.3; CI, 1.5-5.4). Patients with resistant healthcare-associated infections also had a significantly higher death rate (0.04; CI, 0.01-0.08). With careful matching of patients infected with the same organism, antimicrobial resistance was associated with higher charges, length of stay, and death rates. The difference in estimates after accounting for censoring for death highlight divergent social and hospital incentives in reducing patient risk for antimicrobial resistant infections.

Asthma and Risk of Community-Associated Blood Stream Infection Due to Staphylococcus aureus: A Population-Based Case-Control Study

Patients with asthma harbor an increased risk of invasive pneumococcal infection (IPD). It is unknown whether there is a similar association between asthma and community-associated blood stream infection (BSI) caused by Staphylococcus aureus.

Air Pollution And Environmental Tobacco Smoking During Infancy May Increase The Risk Of Bronchiolitis

M O N D A Y 623 Asthma and Risk of Community-Associated Blood Stream Infection Due to Staphylococcus aureus: A Population-Based Case-Control Study J. Lee, H. Yang, W. Atrouni, L. Baddour, B. Yawn, Y. Juhn; Department of Pediatrics,Samsung Changwon Hospital, Changwon-si, REPUBLIC OF KOREA, Department of Pediatric and Adolescent Medicine, Mayo Clinic, Rochester, MN, Department of Pediatrics,Soonchunhyang University Hospital, Seoul, REPUBLIC OF KOREA, Division of Infectious Diseases, Department of Internal Medicine,University of Kansas Medical Center, Kansas, KS, Division of Infectious Diseases, Department of Medicine,Mayo Clinic, Rochester, MN, Department of Research, Olmsted Medical Center, Rochester, MN. RATIONALE: Patients with asthma harbor an increased risk of invasive pneumococcal infection (IPD). It is unknown whether there is a similar association between asthma and community-associated blood stream infection (BSI) caused by Staphylococcus aureus. METHODS: Subjects were adult residents of Olmsted County, MN, who developed community-associated BSI caused by S. aureus between 1998 and 2005; three ageand sex-matched controls were also evaluated. The associations between asthma and community-associated BSI caused by S. aureus were assessed by Fischer exact test. RESULTS: Of the 43 BSI cases, 70% were male, 86% were Caucasians, and the median age was 59 years. Five (11.6%) of them were asthmatics as compared to 9 (7%) of 129 controls (p50.34). Compared to non-asthmatics, asthmatics had a lower ICU admission rate (34% vs 0%, p50.3) and lower Pitt-bacteremia scores (2.362.7 vs. 0.860.5, p50.13), a shorter hospital stay (13.6614.7 days vs. 11.462.1 days,p50.59), and lower mortality rates (13.0% vs. 0.0%, p51.0), but these differences were not statistically significant. CONCLUSIONS: Unlike IPD, asthma is not significantly associated with risk and severity of BSI caused by S. aureus. Designation of specific pathogenmay be one of several key factors in an association of asthmawith risk and severity of BSI. However, a small sample size significantly limited the current investigation.

Asthma and Severity of Blood Stream Infection Caused by Escherichia coli: A Population-Based Study

M O N D A Y 623 Asthma and Risk of Community-Associated Blood Stream Infection Due to Staphylococcus aureus: A Population-Based Case-Control Study J. Lee, H. Yang, W. Atrouni, L. Baddour, B. Yawn, Y. Juhn; Department of Pediatrics,Samsung Changwon Hospital, Changwon-si, REPUBLIC OF KOREA, Department of Pediatric and Adolescent Medicine, Mayo Clinic, Rochester, MN, Department of Pediatrics,Soonchunhyang University Hospital, Seoul, REPUBLIC OF KOREA, Division of Infectious Diseases, Department of Internal Medicine,University of Kansas Medical Center, Kansas, KS, Division of Infectious Diseases, Department of Medicine,Mayo Clinic, Rochester, MN, Department of Research, Olmsted Medical Center, Rochester, MN. RATIONALE: Patients with asthma harbor an increased risk of invasive pneumococcal infection (IPD). It is unknown whether there is a similar association between asthma and community-associated blood stream infection (BSI) caused by Staphylococcus aureus. METHODS: Subjects were adult residents of Olmsted County, MN, who developed community-associated BSI caused by S. aureus between 1998 and 2005; three ageand sex-matched controls were also evaluated. The associations between asthma and community-associated BSI caused by S. aureus were assessed by Fischer exact test. RESULTS: Of the 43 BSI cases, 70% were male, 86% were Caucasians, and the median age was 59 years. Five (11.6%) of them were asthmatics as compared to 9 (7%) of 129 controls (p50.34). Compared to non-asthmatics, asthmatics had a lower ICU admission rate (34% vs 0%, p50.3) and lower Pitt-bacteremia scores (2.362.7 vs. 0.860.5, p50.13), a shorter hospital stay (13.6614.7 days vs. 11.462.1 days,p50.59), and lower mortality rates (13.0% vs. 0.0%, p51.0), but these differences were not statistically significant. CONCLUSIONS: Unlike IPD, asthma is not significantly associated with risk and severity of BSI caused by S. aureus. Designation of specific pathogenmay be one of several key factors in an association of asthmawith risk and severity of BSI. However, a small sample size significantly limited the current investigation.