Community-acquired Bloodstream Infections Research Articles

Predicting community acquired bloodstream infection in infants using full blood count parameters and C-reactive protein; a machine learning study.

Early recognition of bloodstream infection (BSI) in infants can be difficult, as symptoms may be non-specific, and culture can take up to 48 h. As a result, many infants receive unneeded antibiotic treatment while awaiting the culture results. In this study, we aimed to develop a model that can reliably identify infants who do not have positive blood cultures (and, by extension, BSI) based on the full blood count (FBC) and C-reactive protein (CRP) values.Several models (i.e. multivariable logistic regression, linear discriminant analysis, K nearest neighbors, support vector machine, random forest model and decision tree) were trained using FBC and CRP values of 2693 infants aged 7 to 60 days with suspected BSI between 2005 and 2022 in a tertiary paediatric hospital in Dublin, Ireland.All models tested showed similar sensitivities (range 47% - 62%) and specificities (range 85%-95%). A trained decision tree and random forest model were applied to the full dataset and to a dataset containing infants with suspected BSI in 2023 and showed good segregation of a low-risk and high-risk group. Negative predictive values for these two models were high for the full dataset (> 99%) and for the 2023 dataset (> 97%), while positive predictive values were low in both dataset (4%-20%). Conclusion:We identified several models that can predict positive blood cultures in infants with suspected BSI aged 7 to 60 days. Application of these models could prevent administration of antimicrobial treatment and burdensome diagnostics in infants who do not need them. What is Known: •Bloodstream infection (BSI) in infants cause non-specific symptoms and may be difficult to diagnose. • Results of blood cultures can take up to 48 hours. What is New: •Machine learning models can contribute to clinical decision making on BSI in infants while blood culture results are not yet known.

Epidemiology and antimicrobial susceptibility profiles of Enterobacterales causing bloodstream infections before and during COVID-19 pandemic: Results of the Study for Monitoring Antimicrobial Resistance Trends (SMART) in Taiwan, 2018–2021

BackgroundThe coronavirus disease 2019 (COVID-19) pandemic has contributed to the spread of antimicrobial resistance, including carbapenem-resistant Enterobacterales. MethodsThis study utilized data from the Study for Monitoring Antimicrobial Resistance Trends (SMART) surveillance program in Taiwan. Enterobacterales from patients with bloodstream infections (BSIs) were collected and subjected to antimicrobial susceptibility testing and β-lactamase gene detection using a multiplex PCR assay. Statistical analysis was conducted to compare susceptibility rates and resistance genes between time periods before (2018–2019) and during the COVID-19 pandemic (2020–2021). ResultsA total of 1231 Enterobacterales isolates were collected, predominantly Escherichia coli (55.6%) and Klebsiella pneumoniae (29.2%). The proportion of nosocomial BSIs increased during the COVID-19 pandemic (55.5% vs. 61.7%, p < 0.05). Overall, susceptibility rates for most antimicrobial agents decreased, with Enterobacterales from nosocomial BSIs showing significantly lower susceptibility rates than those from community-acquired BSIs. Among 123 Enterobacterales isolates that underwent molecular resistance mechanism detection, ESBL, AmpC β-lactamase, and carbapenemase genes were detected in 43.1%, 48.8% and 16.3% of the tested isolates, respectively. The prevalence of carbapenemase genes among carbapenem-resistant Enterobacterales increased during the pandemic, although the difference was not statistically significant. Two novel β-lactamase inhibitor combinations, imipenem-relebactam and meropenem-vaborbactam, preserved good efficacy against Enterobacterales. However, imipenem-relebactam showed lower in vitro activity against imipenem-non-susceptible Enterobacterales than that of meropenem-vaborbactam. ConclusionsThe COVID-19 pandemic appears to be associated with a general decrease in antimicrobial susceptibility rates among Enterobacterales causing BSIs in Taiwan. Continuous surveillance is crucial to monitor antimicrobial resistance during the pandemic and in the future.

Association between blood culture turnaround time and clinical prognosis in emergency department patients with community acquired bloodstream infection: A retrospective study based on electronic medical records

ImportancePrevious investigations have found that time to positive blood culture (TTP) is a prognostic factor for clinical outcomes. In fact, what the emergency physician sees from the medical information system is TAT (turnaround time) defined as time required to post a bacterial culture report. We propose a definition of blood culture TAT that more closely aligns with clinical considerations by measuring the time from starting specimen culture to the release of an official blood culture report.We were curious to know whether the duration of TAT is as intricately linked to the prognosis of bacteremia as TTP. ObjectivesTo examine the association between TAT and outcomes of adult patients who present to the ED with community acquired bacteremia. DesignSetting, and Participants: This retrospective study utilized electronic medical records from Kaohsiung Veterans General Hospital (KVGH), a 1000-bed tertiary medical center in Taiwan. Patients were adults aged 18 years and older who presented to ED (Emergency department) for initial diagnosis of community acquired bacteremia from January 1, 2016 to March 31, 2021. Data analysis was performed from December 2022 to January 2023.Main outcomes and measures.The primary outcomes included mortality in the ED, all-cause in-hospital mortality, length of hospital stay, and all-cause 30-day mortality in relation to the individual first report of positive blood culture TAT. ResultsA total of 4011 eligible patients with bacteremia were evaluated, of which 207 patients had a blood culture TAT of ≤48 h. The overall 30-day all-cause mortality rate was 13%. Contrary to expectation, no statistically significant differences were observed in clinical prognosis between the TAT groups (≤48 versus >48 h). Subgroup analyses indicated that the length of TAT did not have a significant effect on clinical prognosis in patients who underwent lactate level assessment. Furthermore, no difference in clinical outcome was noted between TAT groups (≤48 versus >48 h) in terms of Gram-negative bacilli or Gram-positive cocci bacteremia. However, in patients with delayed antibiotic treatment (>3 h), a shorter TAT was significantly associated with a fatal outcome. ConclusionIn adults with community-acquired bacteremia, this study did not observe a significant association between blood culture TAT and clinical prognosis, except in cases of delayed antibiotic treatment.

[Pathogenic characteristics and influence factors of bloodstream infection-induced severe sepsis in pediatric intensive care unit].

Objective: To summarize the pathogenic characteristics of bloodstream infection (BSI)-induced severe sepsis and analyze the influence factors in pediatric intensive care unit (PICU). Methods: Pediatric patients who were diagnosed with severe sepsis caused by BSI in the PICU of Children's Hospital Affiliated to Shanghai Jiao Tong University School of Medicine from January 2016 to December 2021 were retrospectively selected and divided into survival group and death group according to their discharge outcomes. Clinical characteristics, laboratory parameters, pathogenic characteristics and drug resistance of the patients were collected. The characteristics of pathogens, clinical and laboratory indicators were summarized, and the influencing factors of death in children with severe sepsis caused by BSI were analyzed based on binary multivariate logistic regression. Results: A total of 132 patients, aged [M (Q1, Q3)] 36 (10, 119) months, with BSI-induced severe sepsis were enrolled in this study, including 81 males and 51 females. There were 38 cases aged 36 (15, 120) months in the death group, including 23 males and 15 females. There were 94 cases, aged 36 (8, 108) months, in the survival group, including 58 males and 36 females. A total of 132 strains of pathogens were isolated, including 87 strains (65.9%) of Gram-negative bacteria. The top 5 pathogens were Klebsiella pneumoniae (24 cases, 18.2%), Escherichia coli (17 cases, 12.9%), Acinetobacter baumannii (13 cases, 9.8%), Pseudomonas aeruginosa (10 cases, 7.6%) and Staphylococcus aureus (10 cases, 7.6%). The proportion of multi-drug resistant bacteria in hospital-acquired BSI was higher than that in community-acquired BSI [52.9% (36/68) vs 15.6% (10/64), P=0.001]. The proportions of community-acquired infection were 58.5% (55/94) and 23.7% (9/38) in the survival and death groups, respectively, the difference was statistically significant (P<0.001). The proportion of central venous catheter insertion before bloodstream infection in the death group was higher than that in the survival group [63.2% (24/38) vs 42.6% (40/94), P=0.034]. According to the binary multivariate logistic regression analysis, hospital-acquired infection (OR=4.80, 95%CI: 1.825-12.621, P=0.001), absolute neutrophil count (ANC) (OR=0.93, 95%CI: 0.863-0.993, P=0.030) and decreased albumin (OR=0.89, 95%CI: 0.817-0.977, P=0.014) were risk factors for death. Conclusions: The common pathogen of BSI-induced severe sepsis in PICU is Gram-negative bacteria. The proportion of multi-drug resistant organisms of BSI obtained in hospitals is high. Children with severe sepsis due to BSI with nosocomial acquired infection, ANC and decreased albumin have a high risk of death.

An Interprofessional Quality Improvement Project to Reduce Community-Acquired Central Line-Associated Bloodstream Infections in the Pediatric Intestinal Failure Population

Highlights Abstract Aim: Central line-associated bloodstream infections (CLABSIs) result in significant morbidity but are largely preventable. Methods to reduce hospital-acquired CLABSIs are well described, but few recommendations exist for how these practices might translate to patients with central lines in the ambulatory setting. This team sought to reduce the mean monthly community-acquired CLABSI rate by 25% from 11.7 to 8.8 per 1000 community line-days in children with intestinal failure who require home parenteral nutrition within 12 months. Methods: First, an interprofessional quality improvement team was formed. After baseline data collection, plan-do-study-act cycles began. Tests of change consisted of a central venous catheter (CVC) maintenance bundle. This bundle included a CVC care tote with additional supplies, improved educational materials, and ethanol lock prophylaxis. A control chart was used to display the monthly community-acquired CLABSI rate and observe for special cause variation. Results: At baseline, the average monthly community-acquired CLABSI rate was 11.7 per 1000 community catheter-days. The home CVC maintenance bundle was implemented, after which there were 5 consecutive months with no infections. After enhancements to the care bundle and tote, special cause variation was noted, and the average monthly community-acquired CLABSI rate declined by 66% to 4 per 1000 community catheter-days. Special cause variation was noted at 2 other time points without an identifiable cause. Conclusion: A lower community-acquired CLABSI rate has been sustained for 24 months and reflects approximately 12 fewer infections per year in this at-risk population.

Gender and Age Dependent Bacteriological Etiology of Community-Acquired Blood Stream Infection

 Background: Bloodstream infection constitutes one of the most serious situations in infectious disease. Objective: The purpose of the presents study was to determine the gender and age dependent etiology of community- acquired urinary blood stream infection. Methodology: This was a retrospective analysis of blood samples from clinically suspected cases of blood stream infection. Samples were collected at Ad-din Women’s Medical College Hospital, Dhaka &amp; Rushmono Specialized Hospital, Dhaka from January 2018 to September 2018. All the samples were collected from inpatient’s and outpatient’s department of our hospital during the study period and processed in Microbiology laboratory. The BD BACTEC FX40 automated blood culture method was used to isolate bacterial pathogens and antimicrobial susceptibility test was performed by Kirby-Bauer disc diffusion method. Results: A total of 483 (16.1%) pathogens were isolated from 3018 bacteremia suspect patient blood specimens. Gram-negative cocci (58.4%) were predominant organisms recovered followed by Gram-positive bacilli (41.6%). Majority of BSI were caused by Gram negative bacteria predominantly Salmonella Typhi (31.1%). Salmonella species was found less prevalent in the children (55%) and more frequent in the age groups 16 to 30 years (85.0%) and more than 60 years (100.0%). Acinetobacter species was found less prevalent in age group 16 to 30 years (7.5%). Escherichia coli was found only few prevalent in the 1 to 15 (0.5%) and higher frequent in the age groups 16 to 30 years (2.5%). Salmonella species isolates appeared to be sensitive to ceftriaxone (91.3%), meropenem (90.7%) and cotrimoxazole (76%). Sensitivity rates of ciprofloxacin, gentamycin and levofloxacin were 87.3% for coagulase-negative Staphylococcus species (CoNS). Conclusion: Both patients’ age and gender are significant factors in determining bloodstream infection. Bangladesh Journal of Medical Microbiology, January 2023;17(1):3-9

Klebsiella pneumoniae bacteraemia epidemiology: resistance profiles and clinical outcome of King Fahad Medical City isolates, Riyadh, Saudi Arabia

Background and objectivesKlebsiella pneumoniae (K. pneumoniae) is the second leading cause of community-acquired and hospital-acquired gram-negative bloodstream infection (BSI). This study aimed to assess the epidemiological and microbial-resistance characteristics and clinical factors associated with K. pneumoniae BSI in Saudi Arabia.Materials and MethodsData of 152 K. pneumoniae isolates diagnosed between January 2019 and January 2020 at King Fahad Medical City, Riyadh, Saudi Arabia were evaluated retrospectively. Clinical records of the patients were collected and analysed statistically.ResultsIn total, 152 cases of K. pneumoniae BSI were identified. Adult patients (66.4%) were at a higher risk of developing the infection than paediatric patients (33.6%). The rate of infection was slightly higher in women than in men. Neurological disorders were the predominant underlying conditions for the acquisition of K. pneumoniae BSI, at all ages. Most of the deceased patients were adults with multi-organ dysfunction. Klebsiella pneumoniae showed disturbing resistance to amoxicillin-clavulanate and cefuroxime (72.4%), ceftazidime (67.8), cephalothin (76.3%), and to Carbapenems (36.1%).ConclusionsThe impact of K. pneumoniae BSI was seen not only at the patient level, but also at the community level, and was related to multi-drug resistant infection. These findings provide a better understanding of microbial resistance and its association with patient clinical outcomes.

Development and Validation of a Prognostic Model for Multi-Drug-Resistant Non-Hospital-Acquired Bloodstream Infection

Bloodstream infections (BSI) are an increasing cause of admissions to hospitals. Non-hospital-acquired BSI are defined by blood cultures that are positive less than 48 hours after admission, but a relevant difference exists between community-acquired and healthcare-associated (HCA) BSI in terms of risk of multidrug resistance (MDR). We planned a retrospective study in three different cohorts in order to develop and to temporally and spatially validate an easy and rapid prognostic model for identifying MDR non-hospital-acquired (non-HA) BSI. The pathogens most involved in BSI are Staphylococcus spp. and Escherichia coli, responsible for about 75% of all MDR isolated. The model includes age, gender, long-term care facility admission, immunocompromise, any recent invasive procedures and central line placement, recent intravenous treatment and antibiotic treatment. It shows an acceptable performance, especially for intermediate probabilities of MDR infection, with a C-index of 70%. The model was proposed in a nomogram that could allow better targeting of antibiotic therapy for non-HA BSI admitted in hospital. However, it should be further validated to determine its applicability in other populations.

Usefulness of procalcitonin at admission as a risk-stratifying biomarker for 50-day in-hospital mortality among patients with community-acquired bloodstream infection: an observational cohort study

PurposeTo assess the association between plasma procalcitonin concentration at hospital admission and the risk of 50-day in-hospital mortality among patients with community-acquired bloodstream infections.MethodsWe carried out a retrospective, observational cohort study with all consecutive patients with bacteriologically confirmed community-acquired bloodstream infections hospitalized between 2006 and 2012. We aimed to assess the association between plasma procalcitonin at admission and 50-day in-hospital mortality. Patients were included in the analysis if they had undergone a blood culture test within 48 hours of hospitalization with a concomitant procalcitonin assay (time < 12 hours between the two tests). Inclusion in the study began on the day of hospital admission, and each patient was followed until death, discharge from the hospital, or last known follow-up in the 50 days following hospital admission. The endpoint was the occurrence of all-cause in-hospital mortality during the 50 days following hospital admission.ResultsDuring the 7-year study period, 1593 patients were admitted to one of the healthcare facilities of the University Hospital of Nancy from home or through the emergency department and had positive blood cultures and concomitant procalcitonin assays. Among the patients, 452 met the selection criteria and were analyzed. In ROC analysis, procalcitonin at baseline was significantly associated with 50-day in-hospital mortality, with an optimal threshold > 4.24 ng/mL. A baseline procalcitonin > 4.24 ng/mL was independently associated with an increased risk of in-hospital mortality (multivariable logistic regression: odds ratio, 2.58; 95% CI, 1.57–4.25; P = 0.0002; Cox proportional hazard regression: hazard ratio, 2.01; 95% CI, 1.30–3.11; P = 0.002). In sensitivity analyses, baseline procalcitonin quartiles were independently associated with 50-day in-hospital mortality (multivariable logistic regression: odds ratio, 1.47; 95% CI, 1.17–1.85; P = 0.001; Cox proportional hazard regression: hazard ratio, 1.31; 95% CI, 1.07–1.60; P = 0.008). The independent associations between baseline procalcitonin and the risk of 50-day in-hospital mortality were maintained after adjusting for C-reactive protein and sepsis status at admission.ConclusionOur data provide the first evidence of the usefulness of plasma procalcitonin at admission as a risk-stratifying biomarker for predicting 50-day in-hospital mortality among patients with community-acquired bloodstream infections.

Laboratory diagnosis of community-acquired bloodstream infection in therapeutic pathology.

Community-acquired bloodstream infections (CBSIs) occur in the out-of-hospital setting (44%) and increase the overall mortality from bloodstream infections (BSIs) by 7.2% per year. The development of CBSIs depends on both comorbid and polymorbid diseases and the patients' age. The causes of CBSIs are: respiratory, hepatobiliary gastrointestinal and urogenital tracts and dental interventions. The etiology of CBSIs is characterized by the isolation of coagulase-negative staphylococci (CNS) (32%), E. coli (27%). To investigate community-acquired bloodstream infection in therapeutic patients. The study included out-of-hospital patients (n=382). 4.5 ml of blood were taken intravenously into a closed vacuum system in order to obtain a buffy coat of blood, which was put on glasses for microscopy and Petri dishes with blood agar for cultivating under aerobic and anaerobic conditions. Microorganisms were identified by mass spectrometry. Microscopy of blood smears was used for rapid diagnosis of infection in the bloodstream. BSI was diagnosed in 183 (48.0%) out of 382 out-of-hospital patients. The etiology of CBSIs was studied on 297 isolated strains of microorganisms. CBSIs rather often complicated the underlying disease in women and young people. The spectrum of CBSI pathogens included aerobic and anaerobic bacteria and fungi. Gram-positive cocci with the leadership of S.epidermidis (25.7%) were more often isolated among bacteria. 70% of all isolated pathogens grew under anaerobic conditions. CBSIs were characterized by polymicrobiality (33.5%) of two to four different microorganisms in one blood culture; the species of associates of polymicrobial blood cultures are shown. Microscopic examination of blood smears revealed microorganisms in 97.1% of cases, including associations of bacteria with fungi (66.9%). CBSIs occurred after contour plastic, in diseases of the respiratory system, genitourinary system, oral cavity, skin and subcutaneous tissue. Microbiological examination of the buffy coat is an alternative microbiological method of CBSIs diagnosis, which includes microscopy and blood cultivating and has a high diagnostic efficiency (97.1% and 48% respectively). It can become an option for replacing imported blood culture automated systems.

Development and validation of an emergency bloodstream infection score for predicting in-hospital mortality in patients with community-acquired bloodstream infections.

Community-acquired bloodstream infections (CABSIs) are common in the emergency departments, and some progress to sepsis and even lead to death. However, limited information is available regarding the prediction of patients with high risk of death. The Emergency Bloodstream Infection Score (EBS) for CABSIs was developed to visualize the output of a logistic regression model and was validated by the area under the curve (AUC). The Mortality in Emergency Department Sepsis (MEDS), Pitt Bacteremia Score (PBS), Sequential Organ Failure Assessment (SOFA), quick Sequential Organ Failure Assessment (qSOFA), Charlson Comorbidity Index (CCI), and McCabe-Jackson Comorbid Classification (MJCC) for patients with CABSIs were computed to compare them with EBS in terms of the AUC and decision curve analysis (DCA). The net reclassification improvement (NRI) index and integrated discrimination improvement (IDI) index were compared between the SOFA and EBS. A total of 547 patients with CABSIs were included. The AUC (0.853) of the EBS was larger than those of the MEDS, PBS, SOFA, and qSOFA (all P<0.001). The NRI index of EBS in predicting the in-hospital mortality of CABSIs patients was 0.368 (P=0.04), and the IDI index was 0.079 (P=0.03). DCA showed that when the threshold probability was < 0.1, the net benefit of the EBS model was higher than those of the other models. The EBS prognostic models were better than the SOFA, qSOFA, MEDS, and PBS models in predicting the in-hospital mortality of patients with CABSIs.

Differences in the distribution of pathogens and antimicrobial resistance in bloodstream infections in migrants compared with non-migrants in Denmark

Background We wish to study disparities in bloodstream infections in migrants and non-migrants by comparing the distribution of pathogens and their resistance patterns in long-term migrants with that in non-migrants in Denmark. Methods The study is based on a cohort of migrants, who received residency in Denmark between 1993 and 2015 and a control group of non-migrants. The cohort was linked to a database of bloodstream infections from 2000 to 2015 covering two regions in Denmark. First-time bloodstream infections in individuals ≥18 years of age at the time of sampling were included. We calculated odds ratios adjusted for age, sex, year of sampling, comorbidity, and place of acquisition (hospital- or community-acquired). Results We identified 4,703 bloodstream infection cases. Family-reunified migrants and refugees had higher odds of Escherichia coli than non-migrants (OR 1.89 95%CI: 1.46–2.44 and OR 1.55 95%CI: 1.25–1.92) and lower odds of Streptococcus pneumoniae (OR 0.38 95%CI: 0.21–0.67 and OR 0.52 95%CI: 0.34–0.81). Differences in pathogen distribution were only prevalent in community-acquired bloodstream infections. Refugees had higher odds of Escherichia coli resistant to piperacillin-tazobactam, ciprofloxacin, and gentamicin compared with non-migrants. Family-reunified migrants had higher odds of Escherichia coli and other Enterobacterales resistant to ciprofloxacin. Conclusions Migrants had a higher proportion of community-acquired bloodstream infections with Escherichia coli as well as higher odds of bloodstream infections with resistant Escherichia coli compared with non-migrants. These novel results are relevant for improving migrant health by focussing on preventing and treating infections especially with Escherichia coli such as urinary tract and abdominal infections.

Bloodstream infections in Injecting drug users: A 15 year prospective single-centre study

• IDUs accounted for nearly 8% of all community acquired bloodstream infections. • S . aureus and S. pyogenes were the most common pathogens. • The commonest foci of infection were skin/soft tissue and septic thrombophlebitis. • Infective endocarditis was relatively uncommon but was associated with mortality. • Septic thrombophlebitis caused more septic pulmonary emboli than endocarditis. To describe the microbiological and clinical characteristics of bloodstream infections (BSIs) in Injecting Drug Users (IDUs). All episodes of community-acquired BSI in IDUs were reviewed. Demographic, clinical and microbiological data were analysed. Detailed analyses were performed for septic thrombophlebitis and infective endocarditis (IE). Historical analysis of microbiological characteristics of BSIs from 1970 to 2018 was performed. There were 406 episodes of BSI in IDUs accounting for 7.8 % of community-acquired BSIs from 2004 to 2018. Patients were male in 77.3 % of episodes. Median age was 38.1 years. Positive HIV status was confirmed in 14 % of episodes. The commonest infecting species were Staphylococcus aureus (45.8 %) and Streptococcus pyogenes (11.8 %). Polymicrobial BSIs accounted for 20.2 % of infections; other streptococci (12.8 %), gram-negative bacilli (4.9 %) and anaerobes (2.7 %) accounted for most of the remainder. The commonest foci of infection were skin and soft tissue (26.4 %), septic thrombophlebitis (20.4 %), bone and joint (17.5 %) and IE (11.8 %). Overall inpatient mortality was 5.9 %. IE and necrotizing fasciitis were associated with increased risk of death. IDUs accounted for a significant proportion of community-acquired BSIs. Skin and soft tissue infection and septic thrombophlebitis were the commonest foci of infection. IE is rare, but mortality is high.

Decrease of hospital- and community-acquired bloodstream infections due to Streptococcus pneumoniae and Streptococcus pyogenes during the first year of the COVID-19 pandemic: A time-series analysis in Paris region

The impact of the COVID-19 pandemic on bloodstream infections (BSIs) due to Streptococcus pneumoniae and Streptococcus pyogenes was assessed in 25 university hospitals of Paris. Monthly BSIs incidence rates that appeared stable in 2018 and 2019, decreased for the two pathogens during the two COVID-19 lockdown periods of 2020. Containment policies, including social distancing, masking and hand hygiene strengthening in both community and hospital settings are likely to reduce BSIs due to these pathogens.

Early deaths associated with community-acquired and healthcare-associated bloodstream infections: a population-based study, Finland, 2004 to 2018.

BackgroundBloodstream infections (BSI) cause substantial morbidity and mortality.AimWe explored the role of causative pathogens and patient characteristics on the outcome of community-acquired (CA) and healthcare-associated (HA) BSI, with particular interest in early death.MethodsWe used national register data to identify all BSI in Finland during 2004–18. We determined the origin of BSI, patients´ underlying comorbidities and deaths within 2 or 30 days from specimen collection. A time-dependent Cox model was applied to evaluate the impact of patient characteristics and causative pathogens on the hazard for death at different time points.ResultsA total of 173,715 BSI were identified; 22,474 (12.9%) were fatal within 30 days and, of these, 6,392 (28.4%) occurred within 2 days (7.9 deaths/100,000 population). The 2-day case fatality rate of HA-BSI was higher than that of CA-BSI (5.4% vs 3.0%). Patients who died within 2 days were older than those alive on day 3 (76 vs 70 years) and had more severe comorbidities. Compared with other BSI, infections leading to death within 2 days were more often polymicrobial (11.8% vs 6.3%) and caused by Pseudomonas aeruginosa (6.2% vs 2.0%), fungi (2.9% vs 1.4%) and multidrug-resistant (MDR) pathogens (2.2% vs 1.8%), which were also predictors of death within 2 days in the model.ConclusionsOverrepresentation of polymicrobial, fungal, P. aeruginosa and MDR aetiology among BSI leading to early death is challenging concerning the initial antimicrobial treatment. Our findings highlight the need for active prevention and prompt recognition of BSI and appropriate antimicrobial treatment.

Risk Factors and Outcomes of Bloodstream Infections Among People With Human Immunodeficiency Virus: A Longitudinal Cohort Study From 2000 to 2017.

BackgroundBloodstream infections (BSIs) among people with human immunodeficiency virus (PWH) remain a poorly studied source of morbidity and mortality. We characterize the epidemiology, microbiology, and clinical outcomes including reinfection, hospitalization, and mortality rates of both community-acquired and hospital-acquired BSI in PWH.MethodsWe identified all BSI, between January 1, 2000 and December 31, 2017 in PWH in care at Southern Alberta Clinic, by linking data from laboratory and clinical databases. Crude incidence rates per 1000 person-years for BSI and death were calculated. Cox proportional hazards models estimated crude and adjusted hazard ratios (HRs) and 95% confidence intervals (CIs) to conduct a risk factor analysis of BSI in PWH. Logistic regression models with generalized estimating equations estimated crude and adjusted odds ratios (aORs) to identify characteristics associated with 1-year mortality after BSI.ResultsAmong 2895 PWH, 396 BSI episodes occurred in 228 (8%) PWH. There were 278 (72%) Gram-positive and 109 (28%) Gram-negative BSI. People with human immunodeficiency virus with lower CD4 nadirs, higher Charlson comorbidity indices, and hepatitis C virus were at highest risk for BSI. Long-term all-cause mortality was greater in those experiencing BSI (HR, 5.25; 95% CI, 4.21–6.55). CD4 count <200 cells/mm3 measured closest to the time of BSI was associated with 1-year mortality after BSI (aOR, 3.88; 95% CI, 1.78–8.46). Repeat episodes (42%) and polymicrobial BSI (19%) were common.ConclusionsBloodstream infections continue to occur at an elevated rate among PWH with high reoccurrence rates and associated morbidity and mortality. To risk stratify and develop targeted interventions, we identified PWH at greatest risk for BSI. People with human immunodeficiency virus with low immunity at the time of BSI are at highest risk of poor outcomes.

A prospective observational study of community-acquired bacterial bloodstream infections in Metro Manila, the Philippines.

Community-acquired bacterial bloodstream infections are caused by diverse pathogens with changing antimicrobial-resistance patterns. In low-middle income countries in Southeast Asia, where dengue fever is endemic and a leading cause of fever, limited information is available about bacterial bloodstream infections due to challenges of implementing a blood culture service. This study describes bacterial bloodstream pathogens and antimicrobial-resistance patterns in Metro Manila, the Philippines. We aimed to identify the proportion of patients with a positive blood culture, the bacteria isolated and their antimicrobial resistance patterns, and the clinical characteristics of these patients, in this dengue endemic area. We conducted a prospective observational study in a single hospital enrolling febrile patients clinically suspected of having a community-acquired bacterial bloodstream infection between 1st July 2015 and 30th June 2019. Each patient had a blood culture and additional diagnostic tests according to their clinical presentation. We enrolled 1315 patients and a significant positive blood culture was found in 77 (5.9%) including Staphylococcus aureus (n = 20), Salmonella enterica Typhi (n = 18), Escherichia coli (n = 16), Streptococcus pneumoniae (n = 3) and Burkholderia pseudomallei (n = 2). Thirty-four patients had meningococcal disease diagnosed by culture (n = 8) or blood PCR (n = 26). Additional confirmed diagnoses included leptospirosis (n = 177), dengue virus infection (n = 159) and respiratory diphtheria (n = 50). There were 79 (6.0%, 95%CI 4.8%-7.4%) patients who died within 28 days of enrollment. Patients with a positive blood culture were significantly more likely to die than patients with negative culture (15.2% vs 4.4%, P<0.01). Among S. aureus isolates, 11/20 (55%) were methicillin-resistant (MRSA) and ST30: USA1100 was dominant sequence type (88.9%). Antimicrobial-susceptibility was well preserved in S. enterica Typhi. Among hospitalized patients with clinically suspected community-acquired bacterial bloodstream infection in Metro Manila, the Philippines, 5.9% had a blood culture confirmed infection of whom 15.6% died. S. aureus, including a significant number of MRSA (USA1100 clones), S. enterica Typhi, E.coli and Neisseria meningitidis were frequently identified pathogens.

Epidemiology of Multidrug Resistance among Salmonella enterica serovars typhi and paratyphi A at a Tertiary Pediatric Hospital in India Over a Decade; In-silico Approach to Elucidate the Molecular Mechanism of Quinolone Resistance

BackgroundEnteric fever caused by Salmonella enterica serovar typhi and Salmonella enterica serovar paratyphi A remains one of the most common causes of community-acquired bloodstream infection among children in India. Multidrug resistance is emerging and is a cause of concern as it affects the choice of treatment in enteric fever. MethodIn this study, a 10-year analysis of resistance patterns was done along with in-silico homology modeling and molecular docking to understand the commonly occurring quinolone resistance. ResultsA total of 1010 cases of blood culture–confirmed enteric fevers (S. typhi n=849; S. paratyphi A n=161) were recorded at the study hospital during the period from 2011-2020. Multidrug resistance among cases of S. typhi was 2.12 %, whereas it was completely absent among cases of S. paratyphi A. Fluoroquinolone resistance was high (>95%) throughout the study period. Resistance to ampicillin, chloramphenicol and co-trimoxacole was low (<3%) among S. typhi cases. No deaths were observed among study participants. Molecular docking analysis showed that quinolone had less binding affinity to mutated gyrase A than to its wild type for both S. typhi and S. paratyphi A. ConclusionQuinolone resistance was high among cases of enteric fever, whereas no resistance was observed among third-generation cephalosporins. In-silico studies indicated that a mutation in gyrase A might be the cause of the gradual increase in ciprofloxacin resistance over the study period.

Population Dynamics of Escherichia coli Causing Bloodstream Infections over Extended Time Periods

ABSTRACTEscherichia coli is a leading cause of community-acquired and health care-associated bloodstream infections (BSIs) worldwide. Limited information is available regarding the changes in population dynamics of human E. coli over extended time periods, especially among nonbiased E. coli isolates in large well-defined geographical regions. Coque and colleagues (I. Rodríguez, A. S. Figueiredo, M. Sousa, S. Aracil-Gisbert, et al., mSphere 6:e00868-21, 2021, https://doi.org/10.1128/msphere.00868-21) conducted a longitudinal study of E. coli BSIs in a Madrid hospital over a 21-year period (1996 to 2016). Certain E. coli B2 phylogroups (i.e., ST131 and ST73) dominated the community E. coli population in Madrid. These community clones were often introduced into the hospital setting. This study and other longitudinal surveys from England and Canada showed that ST131 subclades C1 and C2 were mainly responsible for the increase in fluoroquinolone and cephalosporin resistance among E. coli during the mid- to late 2000s.

Rationalising empirical antibiotics for bloodstream infections: A retrospective study at a South African district-level hospital

Background. Incorrect empirical antibiotic therapy is one of the factors that contribute to poor clinical outcomes and the development of antimicrobial resistance. Knowledge of the local infectious disease burden and antibiotic resistance patterns can assist with development of strategies, updating of guidelines and subsequent improvement in initial empirical therapy. Objectives. To determine whether the empirical antibiotic choice for treatment of septic episodes at a district-level hospital was appropriate according to national guidelines, and to describe the epidemiological features of the septic episode population being studied and depict their antibiotic susceptibility profile. Methods. This was a retrospective, descriptive study of adult inpatients with bloodstream infections at Karl Bremer Hospital, Cape Town, South Africa. Laboratory and clinical data were obtained and analysed for the period 1 July 2017 - 30 June 2018. Septic episodes were subdivided into community-acquired bloodstream infection (CABSI) and hospital-acquired bloodstream infection (HABSI) study populations, and empirical antibiotics for both groups were assessed and compared with the adult Standard Treatment Guidelines and Essential Medicines List for South Africa, Hospital Level Care, 2015 edition (STG and EML). Results. Our study sample consisted of 184 septic episodes, isolated from 176 patients. Nearly half of the septic episodes (49.5%) were hospital acquired. Overall guideline adherence in the CABSI population was 88%, compared with 58% in the HABSI population. The reasons for guideline non-adherence in the CABSI population were lack of source-appropriate empirical antibiotics (n=7) and septic episodes where empirical antibiotics were indicated but not prescribed (n=4), while in the HABSI group the main reason was that the patients were treated by community-acquired standards (n=30; 33.0%). The in-hospital mortality rate for a septic episode in this study was 38%. Considering the typical first-line antibiotics used, 77.3% of CABSIs were found to be susceptible to co-amoxiclav (n=75) and 59.8% to ceftriaxone (n=58). With the exclusion of methicillin-resistant Staphylococcus aureus and Acinetobacter baumannii isolates as confounders, HABSIs had a susceptibility of 86% to the piperacillin/tazobactam plus amikacin combination, 81% to ertapenem, 90% to imipenem and 93% to meropenem. Conclusions. This study demonstrates poor guideline adherence in HABSIs, emphasising the importance of distinguishing between CABSIs and HABSIs. The empirical antibiotics advised by the STG and EML were found to be appropriate in the majority of septic episodes. Future revision and improvement of prescribing practices can assist in rationalising empirical antibiotic decisions.