HANDOC: A Handy Score to Determine the Need for Echocardiography in Non-β-Hemolytic Streptococcal Bacteremia

The 2023 new European guidelines on infective endocarditis: main novelties and implications for clinical practice

The 2023 European Society of Cardiology (ESC) guidelines for the management of infective endocarditis update the previous 2015 guidelines with main novelties in five areas: (1) antibiotic prevention for high-risk patients, and prevention measures for intermediate-risk and high-risk patients; (2) diagnosis with emphasis on multimodality imaging to assess cardiac lesions of infective endocarditis' (3) antibiotic therapy allowing an outpatient antibiotic treatment for stabilized, uncomplicated cases; (4) cardiac surgery with an emphasis on early intervention without delay for complicated cases; and (5) shared management decision by the endocarditis team. Most evidence came from observational studies and expert opinions. The guidelines strongly support a patient-centred approach with a shared decision process by a multidisciplinary team that should be implemented either in tertiary referral centres, becoming heart valve centres, and referral centres. A continuous sharing of data is warranted in the hospitals' network between heart valve centres, which are used for referrals for complicated cases of infective endocarditis, and referral centres, which should be able to manage uncomplicated cases of infective endocarditis.

Infective endocarditis is rare in patients with hematologic malignancy and neutropenia

BACKGROUND

Infective endocarditis (IE) is a serious complication of bloodstream infections (BSIs) that occurs at variable rates depending on the pathogen and clinical setting. There is a paucity of data describing the risk of IE in patients with hematologic malignancy who develop bacteremia while neutropenic.

METHODS

Adult patients on the hematology ward from January 2018 to December 2020 with hematologic malignancy and bacteremia were evaluated retrospectively for endocarditis by applying the 2023 Duke-ISCVID criteria. Charts of possible cases were evaluated 90 days after the initial BSI for new infectious complications that could indicate missed IE. Descriptive statistics compared patients admitted for hematopoietic stem cell transplantation (HSCT) to those admitted for alternative reasons (non-HSCT).

RESULTS

Among the 1005 positive blood cultures initially identified, there were 66 episodes in 65 patients with hematologic malignancy and at least grade 3 neutropenia for a mean duration of 11.4 days during their admission. Transthoracic echocardiography (TTE) was performed in 34.8% of BSIs, and transesophageal echocardiography (TEE) in 6.1%. There were no new infectious complications in possible cases 90 days after their initial BSI. No cases of endocarditis were identified.

CONCLUSIONS

Endocarditis is rare amongst patients with hematologic malignancy, bacteremia, and neutropenia, and no cases were identified in this cohort. The use of routine TTE in this setting seems unwarranted, and the addition of TEE is unlikely to improve patient-centered outcomes.

Non-betahemolytic streptococcal bacteremia, cardiac implantable electronic device, endocarditis, extraction, and outcome; a population-based retrospective cohort study

PURPOSE

Patients with non-beta-hemolytic streptococcal bacteremia (NBHSB) are at risk of infective endocarditis (IE). Patients with cardiac implantable electronic device (CIED) have been described to have an increased risk of IE. The aim of the study was to describe a population-based cohort of patients with NBHSB and CIED and variables associated with IE and recurrent NBHSB.

METHODS

All episodes with NBHSB in blood culture from 2015 to 2018 in a population of 1.3 million inhabitants were collected from the Clinical Microbiology Laboratory, Lund, Sweden. Through medical records, patients with CIED during NBHSB were identified and clinical data were collected. Patients were followed 365 days after NBHSB.

RESULTS

Eighty-five episodes in 79 patients with CIED and NBHSB constituted the cohort. Eight patients (10%) were diagnosed with definite IE during the first episode, five of whom also had heart valve prosthesis (HVP). In 39 patients (49%) transesophageal echocardiography (TEE) was performed of which six indicated IE. Four patients had the CIED extracted. Twenty-four patients did not survive (30%) the study period. Four patients had a recurrent infection with NBHSB with the same species, three of whom had HVP and had been evaluated with TEE with a negative result during the first episode and diagnosed with IE during the recurrency.

CONCLUSION

The study did not find a high risk of IE in patients with NBHSB and CIED. Most cases of IE were in conjunction with a simultaneous HVP. A management algorithm is suggested.

Performance of the 2023 Duke-International Society of Cardiovascular Infectious Diseases Diagnostic Criteria for Infective Endocarditis in Relation to the Modified Duke Criteria and to Clinical Management-Reanalysis of Retrospective Bacteremia Cohorts

BACKGROUND

Revised diagnostic criteria for infective endocarditis (IE), the 2023 Duke-ISCVID criteria, were recently presented and need validation. Here, we compare the 2000 modified Duke criteria for IE with Duke-ISCVID among patients with bacteremia and relate the diagnostic classification to IE treatment.

METHODS

We reanalyzed patient cohorts with Staphylococcus aureus, Staphylococcus lugdunensis, non-β-hemolytic streptococci, Streptococcus-like bacteria, Streptococcus dysgalactiae, Enterococcus faecalis, and HACEK (Haemophilus, Aggregatibacter, Cardiobacterium, Eikenella, Kingella) bacteremia. Episodes were classified as definite, possible, or rejected IE with the modified Duke and Duke-ISCVID criteria. Reclassification included the microbiology criteria, positron emission tomography-computed tomography, and cardiac implanted electronic devices. To calculate sensitivity, patients treated for IE were considered as having IE.

RESULTS

In 4050 episodes of bacteremia, the modified Duke criteria assigned 307 episodes (7.6%) as definite IE, 1190 (29%) as possible IE, and 2553 (63%) as rejected IE. Using the Duke-ISCVID criteria, 13 episodes (0.3%) were reclassified from possible to definite IE, and 475 episodes (12%) were reclassified from rejected to possible IE. With the modified Duke criteria, 79 episodes that were treated as IE were classified as possible IE, and 11 of these episodes were reclassified to definite IE with Duke-ISCVID. Applying the decision to treat for IE as a reference standard, the sensitivity of the Duke-ISCVID criteria was 80%. None of the 475 episodes reclassified to possible IE were treated as IE.

CONCLUSIONS

The Duke-ISCVID criteria reclassified a small proportion of episodes to definite IE at the expense of more episodes of possible IE. Future criteria should minimize the possible IE group while keeping or improving sensitivity.

Incidence and predictors of complications in Gram-negative bloodstream infection

BACKGROUND

The incidence of metastatic complications in Gram-negative bloodstream infection (GN-BSI) remains undefined. This retrospective cohort study examines the incidence and predictors of complications within 90 days of GN-BSI.

METHODS

Patients with GN-BSIs hospitalized at two Prisma Health-Midlands hospitals in Columbia, South Carolina, USA from 1 January 2012 through 30 June 2015 were included. Complications of GN-BSI included endocarditis, septic arthritis, osteomyelitis, spinal infections, deep-seated abscesses, and recurrent GN-BSI. Kaplan-Meier analysis and multivariate Cox proportional hazards regression were used to examine incidence and risk factors of complications, respectively.

RESULTS

Among 752 patients with GN-BSI, median age was 66 years and 380 (50.5%) were women. The urinary tract was the most common source of GN-BSI (378; 50.3%) and Escherichia coli was the most common bacteria (375; 49.9%). Overall, 13.9% of patients developed complications within 90 days of GN-BSI. The median time to identification of these complications was 5.2 days from initial GN-BSI. Independent risk factors for complications were presence of indwelling prosthetic material (hazards ratio [HR] 1.73, 95% confidence intervals [CI] 1.08-2.78), injection drug use (HR 6.84, 95% CI 1.63-28.74), non-urinary source (HR 1.98, 95% CI 1.18-3.23), BSI due to S. marcescens, P. mirabilis or P. aeruginosa (HR 1.78, 95% CI 1.05-3.03), early clinical failure criteria (HR 1.19 per point, 95% CI 1.03-1.36), and persistent GN-BSI (HR 2.97, 95% CI 1.26-6.99).

CONCLUSIONS

Complications of GN-BSI are relatively common and may be predicted based on initial clinical response to antimicrobial therapy, follow-up blood culture results, and other host and microbiological factors.

Risk of Infective Endocarditis in Streptococcus mitis Bloodstream Infections Among Patients with Neutropenia from Hematologic Malignancies

Streptococcus mitis commonly causes bloodstream infections (BSIs) in neutropenic patients but infrequently results in infective endocarditis (IE) in this population. Among 210 patients with neutropenia and S. mitis BSI, 55% underwent cardiac imaging. None were diagnosed with S. mitis IE; 3 had recurrent S. mitis BSI within 12 weeks.

Bacteraemia with gram-positive bacteria-when and how do I need to look for endocarditis?

BACKGROUND

Patients with bacteraemia caused by gram-positive bacteria are at risk for infective endocarditis (IE). Because IE needs long antibiotic treatment and sometimes heart valve surgery, it is very important to identify patients with IE.

OBJECTIVES

In this narrative review we present and discuss how to determine which investigations to detect IE that are needed in individual patients with gram-positive bacteraemia.

SOURCES

Published original studies and previous reviews in English, within the relevant field are used.

CONTENT

First, the different qualities of the bacteraemia in relation to IE risk are discussed. The risk for IE in bacteraemia is related to the species of the bacterium but also to monomicrobial bacteraemia and the number of positive cultures. Second, patient-related factors for IE risk in bacteraemia are presented. Next, the risk stratification systems to determine the risk for IE in gram-positive bacteraemia caused by Staphylococcus aureus, viridans streptococci, and Enterococcus faecalis are presented and their use is discussed. In the last part of the review, an account for the different modalities of IE-investigations is given. The main focus is on echocardiography, which is the cornerstone of IE-investigations. Furthermore, 18F-fluorodesoxyglucose positron emission tomography/computed tomography and cardiac computed tomography are presented and their use is also discussed. A brief account for investigations used to identify embolic phenomena in IE is also given. Finally, we present a flowchart suggesting which investigations to perform in relation to IE in patients with gram-positive bacteraemia.

IMPLICATIONS

For the individual patient as well as the healthcare system, it is important both to diagnose IE and to decide when to stop looking for IE. This review might be helpful in finding that balance.

Risk of endocarditis among patients with coagulase-negative Staphylococcus bacteremia

Coagulase-negative staphylococci (CoNS) are currently considered typical microorganisms causing infective endocarditis (IE) in patients with prosthetic valves. The objective was to determine variables associated with IE in patients with CoNS bacteremia. We performed an analysis of the clinical characteristics of patients with CoNS bacteremia admitted to a university hospital in Madrid (Spain) from 2021 to December 2022 according to the occurrence of IE. This study is an evaluation of a bacteremia registry. During the study period, 106 patients with CoNS bacteremia were detected. In 85 patients an echocardiogram was performed during hospital admission to rule out IE. Among them, 12 episodes were detected that met IE criteria (14.2%). Of the 6 patients with heart valve prostheses, 5 patients (83.3%) had IE (p < 0.001). Patients with IE more frequently had positive blood cultures more than 12 h after the first draw (58.3% versus 13.4%; p < 0.001). There was a tendency to associate community-acquired bacteremia and to that all blood culture bottles obtained were positive with an increased risk of IE (p = 0.091 and p = 0,057, respectively). Attributable mortality to infection was higher in patients with IE relative to all other patients (16.7% vs. 0%; p = 0.033). The multivariable analysis included having valve prosthesis and persistent bacteremia for more than 12 h. Both were independently associated with IE: valve prosthesis OR 38.6 (95% CI 5.8-258; p < 0.001) and persistent bacteremia OR 2.6 (95% CI 1.1-6.8; p = 0.046). In conclusion, a high percentage of cases of CoNS bacteremia may be due to IE. Some of the variables related to a higher risk of IE, such as having a valvular prosthesis or presenting positive blood cultures for more than 12 h, should lead to rule out or confirm the presence of IE by performing echocardiography.

Risk and Outcome of Infective Endocarditis in Streptococcal Bloodstream Infections according to Streptococcal Species

This study aimed to identify which streptococcal species are closely associated with infective endocarditis (IE) and to evaluate risk factors for mortality in patients with streptococcal IE. We performed a retrospective cohort study of all patients with streptococcal bloodstream infection (BSI) from January 2010 to June 2020 in a tertiary hospital in South Korea. We compared clinical and microbiological characteristics of streptococcal BSIs according to the diagnosis of IE. We performed multivariate analysis to evaluate the risk of IE according to streptococcal species and risk factors for mortality in streptococcal IE. A total of 2,737 patients were identified during the study period, and 174 (6.4%) were diagnosed with IE. The highest IE prevalence was in patients with Streptococcus mutans BSI (33% [9/27]) followed by S. sanguinis (31% [20/64]), S. gordonii (23% [5/22]), S. gallolyticus (16% [12/77]), and S. oralis (12% [14/115]). In multivariate analysis, previous IE, high-grade BSI, native valve disease, prosthetic valve, congenital heart disease, and community-onset BSI were independent risk factors for IE. After adjusting for these factors, S. sanguinis (adjusted OR [aOR], 7.75), S. mutans (aOR, 5.50), and S. gallolyticus (aOR, 2.57) were significantly associated with higher risk of IE, whereas S. pneumoniae (aOR, 0.23) and S. constellatus (aOR, 0.37) were associated with lower risk of IE. Age, hospital-acquired BSI, ischemic heart disease, and chronic kidney disease were independent risk factors for mortality in streptococcal IE. Our study points to significant differences in the prevalence of IE in streptococcal BSI according to species. IMPORTANCE Our study of risk of infective endocarditis in patients with streptococcal bloodstream infection demonstrated that Streptococcus sanguinis, S. mutans, and S. gallolyticus were significantly associated with higher risk of infective endocarditis. However, when we evaluated the performance of echocardiography in patients with streptococcal bloodstream infection, patients with S. mutans and S. gordonii bloodstream infection had a tendency of low performance in echocardiography. There are significant differences in the prevalence of infective endocarditis in streptococcal bloodstream infection according to species. Therefore, performing echocardiography in streptococcal bloodstream infection with a high prevalence of, and significant association with, infective endocarditis is desirable.

Species designation of streptococci causing infective endocarditis in patients with mitral valve prolapse

OBJECTIVES

Viridans group streptococci (VGS) have been previously linked to infective endocarditis (IE) in patients with mitral valve prolapse (MVP). The species identification of VGS is now available in clinical laboratories; however, it has not been examined in MVP IE. Therefore, we detailed the clinical profile, species designations, and antibiotic susceptibility of VGS isolates from patients with MVP IE.

METHODS

We retrospectively queried all adults with MVP and a definite or possible IE diagnosis seen at medical centers of the Mayo Clinic Enterprise from January 2009 to December 2021. Data, including clinical characteristics, comorbidities, microbiology, and outcomes, were extracted from electronic health records. VGS isolates from patients with MVP and IE were subclassified into mutans, salivarius, anginosus, sanguinis, and mitis groups.

RESULTS

A total of 38 patients with MVP with IE due to streptococcal species were included. Overall, median age was 62.4 years and 32% of patients were females. The most prevalent comorbidities were diabetes mellitus (26%), hypertension (21%), heart failure (16%), and malignancy (16%). A total of (37%) patients presented with an embolic event at the time of their IE diagnosis, 27 (66%) required valve surgery, and no patient died within the hospital stay. The Streptococcus mitis group was the predominant (n = 17, 45%) species designation; S. anginosus and S. sanguinis were identified in three (8%) each; S. mutans in two (5%); and S. salivarius in one (3%). Non-VGS streptococcal pathogens included S. agalactiae in three patients (8%), S. equi in two (5%), and S. dysgalactiae and S. bovis in one each (3%). VGS were identified in five (13%) patients, but species designation was not done. No penicillin resistance was identified among the isolates.

CONCLUSION

The S. mitis group was the predominant species in our investigation. Continued evaluation of VGS species should be considered to profile the IE risk based on species identification.

Streptococcus gordonii empyema: A case report and literature review

Empyema is often caused by Streptococcus anginous species, followed by Streptococcus pneumoniae. The organism Streptococcus gordonii belongs to the Streptococcus mitis group, which rarely causes empyema. We report the case of a 59-year-old man who presented with exertional dyspnea and chest pain on the right side. The image obtained showed effusion on the right side. Streptococcus gordonii was recovered from purulent pleural effusion culture. The patient underwent video-assisted thoracoscopic surgery with decortication, pneumolysis and received antibiotics for 13 days. A total of seven cases were analyzed after combining six cases in the literature and our presented case. The majority of Streptococcus gordonii empyema patients were male (six patients, 86%) and empyema on the right side (five patients, 71%). Common risk factors included poor dental hygiene or recent dental procedure (three patients, 43%), diabetes mellitus (three patients, 43%), and smoking (three patients, 43%). Only a few cases developed empyema-related complications, including bacteremia (one patient, 14%) and spleen abscesses (one patient, 14%). Most patients underwent chest tube insertion (seven patients, 100%) and survived without recurrent empyema (six patients, 86%).

Streptococcal infective endocarditis: clinical features and outcomes according to species

PURPOSE

Infective endocarditis (IE) is frequently caused by streptococcal species, yet clinical features and mortality are poorly investigated. Our aim was to examine patients with streptococcal IE to describe clinical features and outcomes according to streptococcal species.

METHODS

From 2002 to 2012, we investigated patients with IE admitted to two tertiary Danish heart centres. Adult patients with left-sided streptococcal IE were included. Adjusted multivariable logistic regression analyses were performed, to assess the association between streptococcal species and heart valve surgery or 1-year mortality.

RESULTS

Among 915 patients with IE, 284 (31%) patients with streptococcal IE were included [mean age 63.5 years (SD 14.1), 69% men]. The most frequent species were S. mitis/oralis (21%) and S. gallolyticus (17%). Fever (86%) and heart murmur (81%) were common symptoms, while dyspnoea was observed in 46%. Further, 18% of all cases were complicated by a cardiac abscess/pseudoaneurysm and 25% by an embolic event. Heart valve surgery during admission was performed in 55% of all patients, and S. gallolyticus (OR 0.28 [95% CI 0.11-0.69]) was associated with less surgery compared with S. mitis/oralis. In-hospital mortality was 7% and 1-year mortality 15%, without any difference between species.

CONCLUSION

S. mitis/oralis and S. gallolyticus were the most frequent streptococcal species causing IE. Further, S. gallolyticus IE was associated with less heart valve surgery during admission compared with S. mitis/oralis IE. Being aware of specific symptoms, clinical findings, and complications related to different streptococcal species, may help the clinicians in expecting different outcomes.

Bacteraemia and infective endocarditis with Streptococcus bovis-Streptococcus equinus-complex: a retrospective cohort study

BACKGROUND

Streptococcus bovis/equinus complex (SBSEC) comprise several species and subspecies and is a common cause of infective endocarditis (IE). S. gallolyticus subsp. gallolyticus (Sg gallolyticus) accounts for a majority of SBSEC IE, but the risk of IE for other subspecies is largely unknown. We aimed to investigate the clinical presentation of bacteraemia, and proportion of patients with IE in bacteraemia with the most common subspecies.

METHODS

A retrospective cohort study of SBSEC-bacteraemia identified in clinical laboratory databases, in Skåne Region, Sweden, 2003-2018. Bacteraemia with Sg gallolyticus, S. gallolyticus subsp. pasteurianus (Sg pasteurianus), S. lutetiensis and S. infantarius subsp. infantarius (Si infantarius) were included. Subspecies was identified by whole genome sequencing. Medical charts were reviewed according to a predetermined protocol, IE was defined by the criteria from European Society of Cardiology.

RESULTS

In total, 210 episodes of SBSEC-bacteraemia were included. Definite IE was identified in 28/210 (13%) episodes. Of these, 7/28 (25%) were prosthetic valve-IE, 1/28 (4%) related to a cardiovascular implantable electronic device and 10/28 (36%) required heart valve surgery. The proportions of IE among different subspecies were: Sg gallolyticus 17/52 (33%), Si infantarius 5/31 (16%), Sg pasteurianus 4/83 (5%) and S. lutetiensis 2/44 (5%) (p < 0.001). Sg pasteurianus and S. lutetiensis were more often associated with intra-abdominal- and polymicrobial infection.

CONCLUSION

The proportion of IE in SBSEC-bacteraemia varies substantially depending on subspecies. Echocardiography should always be considered in bacteraemia with Sg gallolyticus and Si infantarius, and can sometimes be omitted in bacteraemia with Sg pasteurianus and S. lutetiensis.

Contemporary Experience of Abiotrophia, Granulicatella and Gemella Bacteremia

BACKGROUND

Abiotrophia, Granulicatella, and Gemella are gastrointestinal microbiota, gram-positive cocci that behave like viridans group streptococci. Despite the low incidence of bacteremia from these organisms, they can lead to infective endocarditis (IE) and other clinical syndromes. Due to scant data, we aim to describe detailed clinical features, management, and outcomes of patients with bacteremia from these organisms.

METHODS

We reviewed all adult patients who developed Abiotrophia, Granulicatella, or Gemella bacteremia from 2011 to 2020, at Mayo Clinic.

RESULTS

We identified 238 patients with positive blood culture for these organisms. Of those, 161 (67.6%) patients were deemed to have bacteremia of clinical significance; 62 (38.5%) were neutropenic, - none of whom were diagnosed with IE. The primary source of bacteremia for the neutropenic group was the gastrointestinal tract. Among 161 patients, echocardiography was obtained in 88 (54.7%) patients, especially those with unknown sources of bacteremia. A total of 19 cases had IE: 5 (26.3%) Abiotrophia, 11 (57.9%) Granulicatella, and 3 (15.8%) Gemella. Based on known IE scoring systems, the negative predictive value at established cutoffs for these scores, performed with our cohort were 95.9%, 100% and 97.9% for NOVA, HANDOC and DENOVA scores, respectively. We also found that the penicillin-non-susceptible rate was high in Abiotrophia (66.7%) and Granulicatella (53.7%).

CONCLUSIONS

We described unique characteristics of Abiotrophia, Granulicatella, and Gemella bacteremia at our institution. Clinical significance, clinical syndrome, their proclivity of endocarditis, and susceptibility pattern should be thoroughly reviewed when encountering these organisms.

Blood culture time to positivity in non-β-hemolytic streptococcal bacteremia as a predictor of infective endocarditis-a retrospective cohort study

Non-β-hemolytic streptococci (NBHS) cause infective endocarditis (IE) and a short blood culture time to positivity (TTP) is associated with risk of IE in bacteremia with other pathogens. In this retrospective population-based cohort study, we investigate if TTP is associated to IE or mortality. Of 263 episodes with NBHS bacteremia, 28 represented IE and the median TTP did not differ significantly between episodes with IE (15 h) and non-IE (15 h) (p=0.51). TTP was similar among those who survived and those who died within 30 days. However, TTP significantly differed when comparing the different streptococcal groups (p<0.001).

Development of a Clinical Prediction Model for Infective Endocarditis Among Patients with Undiagnosed Fever: A Pilot Case-Control Study

Purpose

Infective endocarditis (IE) may be diagnosed as fever of unknown origin due to its delusively non-descriptive clinical features, especially in outpatient clinics. Our objective is to develop a prediction model to discriminate patients to be diagnosed as “definite” IE from “non-definite” by modified Duke criteria among patients with undiagnosed fever, using only history and results of physical examinations and common laboratory examinations.

Patients and Methods

The study was a single-center case–control study. Inpatients at Saga University Hospital diagnosed with IE from 2007 to 2017 and patients with undiagnosed fever from 2015 to 2017 were enrolled. Patients diagnosed with definite IE according to the modified Duke criteria, except those definitely diagnosed with other disorders responsible for fever, were allocated to the IE group. Patients without IE among those defined as non-definite according to the modified Duke criteria were allocated to the undiagnosed fever group. We developed a prediction model to pick up patients who would be “definite” by modified Duke criteria, which was subsequently assessed by area under the curve (AUC).

Results

A total of 144 adult patients were included. Of these, 59 patients comprised the IE group. We developed the prediction model using five indicators, including transfer by ambulance, cardiac murmur, pleural effusion, neutrophil count, and platelet count, with a sensitivity 84.7%, a specificity 84.7%, an AUC 0.893 (95% confidence interval 0.828–0.959), a shrinkage coefficient 0.635, and a stratum-specific likelihood ratio 0.2–50.4.

Conclusion

Our prediction model, which uses only indicators easy to gain, facilitates prediction of patients with IE. These indicators can be acquired even at common hospitals and clinics, without requiring advanced medical equipment or invasive examinations.

Trial Registration Number

UMIN000041344.

Valvular and infection-associated risk factors as criteria to guide the use of echocardiography in patients with native joint infections

BACKGROUND

Native joint and bone infections (NJBI) are associated with infective endocarditis (IE) in 15% of cases. There are no studies analyzing the use of cardiac imaging in cases of NJBI. The objective of this study was to identify factors associated with echocardiography suggestive of IE in patients with NJBI.

METHODS

This medical records review was conducted in patients hospitalized for NJBI between 2007 and 2017 in Rheumatology and Infectious Diseases departments of 2 university hospitals. Patients included had a microbiologically proven NJBI during their hospitalization.

RESULTS

In this cohort of 546 patients, median age 66 years, echocardiography was suggestive of IE in 66 (12%). In multivariate analysis, factors associated with echocardiography suggestive of IE were 2 or more positive blood cultures (OR 11.55 (CI95% 3.24-74.20)), cardiac conditions with a high risk of IE (OR 7.34 (CI95% 2.95-18.61)), unknown heart murmur (OR 4.59 (CI95% 1.79-11.74)), multifocal infection (OR 2.26 (CI95% 1.21-4.23)) and an infection due to S. bovis (OR 3.52 (CI95% 1.26-9.79)). The factor associated with the absence of an echocardiography evocative of IE was infection due to unconventional bacteria for IE (OR 0.13 (CI95% 0.01-0.76)). According to the factors associated with echocardiography evocative of IE, we propose the Normandy score based on three kinds of data: cardiac condition, bacterial strain and NJBI mechanism. Echocardiography should be realized when this score, whose negative predictive value is 100% CI95% (98-100%) for prescription of echocardiography, is more than zero.

CONCLUSIONS

A score based on valvular condition, bacterial strain and NJBI mechanism could guide clinicians in prescribing echocardiography during NJBI with an excellent negative predictive value.

Proposal for the use of echocardiography in bloodstream infections due to different streptococcal species

Background

Infective endocarditis (IE) is diagnosed in 7–8% of streptococcal bloodstream infections (BSIs), yet it is unclear when to perform transthoracic (TTE) and transoesophageal echocardiography (TOE) according to different streptococcal species. The aim of this sub-study was to propose a flowchart for the use of echocardiography in streptococcal BSIs.

Methods

In a population-based setup, we investigated all patients admitted with streptococcal BSIs and crosslinked data with nationwide registries to identify comorbidities and concomitant hospitalization with IE. Streptococcal species were divided in four groups based on the crude risk of being diagnosed with IE (low-risk < 3%, moderate-risk 3–10%, high-risk 10–30% and very high-risk > 30%). Based on number of positive blood culture (BC) bottles and IE risk factors (prosthetic valve, previous IE, native valve disease, and cardiac device), we further stratified cases according to probability of concomitant IE diagnosis to create a flowchart suggesting TTE plus TOE (IE > 10%), TTE (IE 3–10%), or “wait & see” (IE < 3%).

Results

We included 6393 cases with streptococcal BSIs (mean age 68.1 years [SD 16.2], 52.8% men). BSIs with low-risk streptococci (S. pneumoniae, S. pyogenes, S. intermedius) are not initially recommended echocardiography, unless they have ≥3 positive BC bottles and an IE risk factor. Moderate-risk streptococci (S. agalactiae, S. anginosus, S. constellatus, S. dysgalactiae, S. salivarius, S. thermophilus) are guided to “wait & see” strategy if they neither have a risk factor nor ≥3 positive BC bottles, while a TTE is recommended if they have either ≥3 positive BC bottles or a risk factor. Further, a TTE and TOE are recommended if they present with both. High-risk streptococci (S. mitis/oralis, S. parasanguinis, G. adiacens) are directed to a TTE if they neither have a risk factor nor ≥3 positive BC bottles, but to TTE and TOE if they have either ≥3 positive BC bottles or a risk factor. Very high-risk streptococci (S. gordonii, S. gallolyticus, S. mutans, S. sanguinis) are guided directly to TTE and TOE due to a high baseline IE prevalence.

Conclusion

In addition to the clinical picture, this flowchart based on streptococcal species, number of positive blood culture bottles, and risk factors, can help guide the use of echocardiography in streptococcal bloodstream infections. Since echocardiography results are not available the findings should be confirmed prospectively with the use of systematic echocardiography.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12879-021-06391-2.

Challenges in the diagnosis and management of Granulicatella elegans endocarditis in a 9-year-old child

A 9-year-old child, with a background of repaired pulmonary atresia and Ebstein's anomaly, presented with fever, night sweats and lethargy. Blood cultures grew Granulicatella elegans, a nutritionally variant Streptococcus and known cause of infective endocarditis (IE). Echocardiogram revealed no clear vegetation, but increased stenosis of the right ventricle to pulmonary artery conduit. The child was successfully managed with high-dose benzylpenicillin, completing 2 weeks in the hospital, and was discharged to complete the final 4 weeks of therapy with ceftriaxone in the community, as per European Society of Cardiology guidance. IE caused by any Granulicatella species is rare, with infection due to G. elegans rarer still. It is a Gram-positive bacteria that presents a diagnostic challenge due to non-specific symptoms at presentation and difficulty in growing the organism on culture medium. We present a case of G. elegans endocarditis in a young child, which illustrates the challenges in managing this condition and the importance of considering atypical organism endocarditis in children presenting with fever of unknown origin, in particular those with a background of congenital cardiac disease. We review the literature on Granulicatella endocarditis, and briefly discuss the challenges of managing this condition in a child with an autism spectrum disorder and learning difficulties.

An Unusual Case of Streptococcus anginosus Endocarditis in a Healthy Host With Bicuspid Aortic Valve

Streptococcus anginosus group (SAG) is a subgroup of viridans streptococci and can be found ubiquitously in normal human flora. SAG is known to form invasive pyogenic infection when it becomes pathogenic. Yet, SAG is a very rare cause of endocarditis, and there is a dearth of case reports on this topic. We present a rare case of native bicuspid aortic valve endocarditis secondary to S. anginosus that caused aortic insufficiency and ascending aortic aneurysm. To our knowledge, this is the first well-documented case report of community-acquired S. anginosus endocarditis on a bicuspid aortic valve in an immunocompetent patient. The patient first presented with cough that was likely due to bronchus irritation from a 5.5 x 5.2 cm ascending aortic aneurysm. He underwent aortic valve replacement with bovine bioprosthesis and ascending aortic aneurysm repairment and was treated with a two-week regimen of IV ceftriaxone and gentamicin followed by another four weeks of IV ceftriaxone. He was eventually discharged to a rehabilitation facility. SAG is usually susceptible to beta-lactam antibiotics. The prognosis of SAG infection is usually good, but progression to bacteremia carries a poor outcome.

Management and treatment of Aerococcus bacteremia and endocarditis

OBJECTIVES

We describe our multicenter experience on diagnosis and management of Aerococcus bacteremia including the susceptibility profile of Aerococcus species and a suggested algorithm for clinicians.

METHODS

Retrospective study of all patients with positive blood cultures for Aerococcus species from January 2005 to July 2020 in our institution with clinical data and susceptibility profile. Data were collected from both electronic health record and clinical microbiology laboratory database.

RESULTS

There were 219 unique isolates with only the susceptibility profiles available, while 81 patients had clinical information available. Forty-nine of those cases were deemed as true bloodstream infection and the rest were of unclear clinical significance. Cases of endocarditis (n = 7) were high-grade, monomicrobial bacteremia caused by Aerococcus urinae. Patients with endocarditis were younger (66 vs 80 p < 0.05). The risk for endocarditis was higher if duration of symptoms was longer than 7 days (OR 105, 95% CI: 5-2271), or if there were septic emboli (OR 71, 95% CI: 3-1612). A DENOVA score cutoff of ≥ 3 was 100% sensitive and 89% specific in detecting endocarditis. The 30-day and 3-month all-cause mortality for bacteremia was 17% and 24%, respectively. Six out of seven patients with endocarditis survived.

CONCLUSIONS

Antibiotic regimen for aerococcal bloodstream infections and endocarditis should be guided by species identification and antimicrobial susceptibility testing. DENOVA scoring system's performance in this study is more congruent to other studies. Hence, it can be used as an adjunctive tool in assessing the need for echocardiogram to rule out endocarditis. In our experience, two and four weeks of treatment for bloodstream infections and endocarditis, respectively, had good outcomes.

Epidemiology, bacteriology, and clinical characteristics of HACEK bacteremia and endocarditis: a population-based retrospective study

The objective was to describe the epidemiology, bacteriology, clinical presentation, risk factors for endocarditis (IE), diagnostic workup, and outcome of patients with bacteremia caused by the non-influenzae Haemophilus, Aggregatibacter, Cardiobacterium, Eikenella, and Kingella genera (HACEK). A retrospective population-based cohort of patients with bacteremia collected from 2012 to 2017 was identified. Clinical data from identified patients were collected from medical records to classify patients, calculate incidences, analyze risk factors of IE, and describe the management and outcome of the cohort. A total of 118 episodes of HACEK bacteremia were identified, of which 27 were definite IE. The incidence of HACEK bacteremia was 5.2 and of HACEK IE 1.2 episodes per 1,000,000 inhabitants per year. Other focal infections were identified in 55 of 118 of the episodes, most commonly within the abdomen (26 episodes). The propensity to cause IE ranged from 62 in Aggregatibacter actinomycetemcomitans to 6% in Eikenella. Risk factors for IE were cardiac implantable electronical device, predisposing cardiac conditions, community acquisition, long duration of symptoms, multiple positive blood cultures, fever, heart murmur, embolization, and unknown origin of infection. The scoring system DENOVA developed to predict IE in bacteremia with Enterococcus faecalis also had a high sensitivity and specificity for predicting IE in HACEK bacteremia. The 30-day mortality was 4% in IE and 15% in non-IE bacteremia, and only one case of relapse was found. IE is common in bacteremia with Aggregatibacter, Cardiobacterium, and Kingella but relatively rare in Haemophilus and Eikenella. Treatment failures are very rare, and DENOVA can be used to evaluate the need for transesophageal echocardiography.

Risk for infective endocarditis in bacteremia with Gram positive cocci

PURPOSE

Infective endocarditis (IE) is a serious complication of bacteremia and is most often caused by Gram positive cocci. We investigated the prevalence of IE in patients where echocardiography was encouraged when bacteremia with Gram positive cocci was present.

METHODS

The study included patients with Gram positive cocci bacteremia hospitalized at two Danish hospitals between March and December 2016. Information concerning echocardiography, demographics and bacterial species was collected from the patients' medical files. Patients without echocardiography were followed for 6 months in order to confirm or reject possible IE.

RESULTS

The study included 585 patients with Gram positive cocci bacteremia, and echocardiography was performed in 414 (71%) of them. The prevalence of IE in patients with high risk bacteremia, i.e. Staphylococcus aureus, non-beta-hemolytic streptococci, Enterococcus faecalis, and coagulase-negative staphylococci was 16%. Patients with Enterococcus faecalis had the highest prevalence of IE (33%) followed by non-beta-hemolytic streptococci (23%) and Staphylococcus aureus (12%). Among low risk bacteremia the prevalence of IE was 1%. The mean age of patients with IE was 74 years (SD 12.9) and 71% were male.

CONCLUSION

These findings strongly support routine echocardiography in patients with high risk bacteremia and non-performance of echocardiography in patients with low risk bacteremia.

An Extremely Rare Case of Streptococcus anginosus Bacteremia Associated With Colon Cancer and Infective Endocarditis

Streptococcus anginosus (S. anginosus) is a subgroup of viridans streptococci that tend to form a deep-seated abscess. These bacteria can be part of healthy human flora and commonly found in the gastrointestinal tract and oral cavity. Infective endocarditis is most commonly caused by Staphylococcus aureus and Streptococcus. Among the Streptococcus group, anginosus is extremely rare to cause endocarditis, and there are only a few case reports available. We present a patient with S. anginosus bacteremia who subsequently got diagnosed with metastatic colon cancer along with aortic and mitral valve endocarditis

Prevalence of Infective Endocarditis in Streptococcal Bloodstream Infections Is Dependent on Streptococcal Species

BACKGROUND

Streptococci frequently cause infective endocarditis (IE), yet the prevalence of IE in patients with bloodstream infections (BSIs) caused by different streptococcal species is unknown. We aimed to investigate the prevalence of IE at species level in patients with streptococcal BSIs.

METHODS

We investigated all patients with streptococcal BSIs, from 2008 to 2017, in the Capital Region of Denmark. Data were crosslinked with Danish nationwide registries for identification of concomitant hospitalization with IE. In a multivariable logistic regression analysis, we investigated the risk of IE according to streptococcal species adjusted for age, sex, ≥3 positive blood culture bottles, native valve disease, prosthetic valve, previous IE, and cardiac device.

RESULTS

Among 6506 cases with streptococcal BSIs (mean age 68.1 years [SD 16.2], 52.8% men) the IE prevalence was 7.1% (95% CI, 6.5-7.8). The lowest IE prevalence was found with Streptococcus pneumoniae (S pneumoniae) 1.2% (0.8-1.6) and Spyogenes 1.9% (0.9-3.3). An intermediary IE prevalence was found with Sanginosus 4.8% (3.0-7.3), Ssalivarius 5.8% (2.9-10.1), and Sagalactiae 9.1% (6.6-12.1). The highest IE prevalence was found with Smitis/oralis 19.4% (15.6-23.5), Sgallolyticus (formerly Sbovis) 30.2% (24.3-36.7), Ssanguinis 34.6% (26.6-43.3), Sgordonii 44.2% (34.0-54.8), and Smutans 47.9% (33.3-62.8). In multivariable analysis using S pneumoniae as reference, all species except S pyogenes were associated with significantly higher IE risk, with the highest risk found with S gallolyticus odds ratio (OR) 31.0 (18.8-51.1), S mitis/oralis OR 31.6 (19.8-50.5), S sanguinis OR 59.1 (32.6-107), S gordonii OR 80.8 (43.9-149), and S mutans OR 81.3 (37.6-176).

CONCLUSIONS

The prevalence of IE in streptococcal BSIs is species dependent with S mutans, S gordonii, S sanguinis, S gallolyticus, and S mitis/oralis having the highest IE prevalence and the highest associated IE risk after adjusting for IE risk factors.

Infective endocarditis: innovations in the management of an old disease

The annual incidence of infective endocarditis (IE) is estimated to be between 15 and 80 cases per million persons in population-based studies. The incidence of IE is markedly increased in patients with valve prostheses (>4 per 1,000) or with prior IE (>10 per 1,000). The interaction between platelets, microorganisms and diseased valvular endothelium is the cause of vegetations and valvular or perivalvular tissue destruction. Owing to its complexity, the diagnosis of IE is facilitated by the use of the standardized Duke-Li classification, which combines two major criteria (microbiology and imaging) with five minor criteria. However, the sensitivity of the Duke-Li classification is suboptimal, particularly in prosthetic IE, and can be improved by the use of PET or radiolabelled leukocyte scintigraphy. Prolonged antibiotic therapy is mandatory. Indications for surgery during acute IE depend on the presence of haemodynamic, septic and embolic complications. The most urgent indications for surgery are related to heart failure. In the past decade, the prevention of IE has been reoriented, with indications for antibiotic prophylaxis now limited to patients at high risk of IE undergoing dental procedures. Guidelines now emphasize the importance of nonspecific oral and cutaneous hygiene in individual patients and during health-care procedures.

External validation of the HANDOC score - high sensitivity to identify patients with non-beta-haemolytic streptococcal endocarditis

Background: Invasive infections with non-beta-haemolytic streptococci (NBHS) is quite common and presents the clinicians with difficulties regarding which patients are at risk for infective endocarditis (IE). The HANDOC score was developed to identify patients with NBHS bacteraemia who are at low risk of IE. This study was conducted to validate HANDOC in an external cohort.Methods: Patients with NBHS in blood cultures between March and September 2016 in a Danish centre were included as part of an on-going study. Patient characteristics were collected to classify bacteria according to Dukés criteria and the components of the HANDOC score were collected retrospectively from the patients' medical records.Results: 68 patients were included in the cohort, of which 16 fulfilled Dukés criteria for IE. All patients with IE (16 of 16) had a HANDOC score above the predefined cut-off. Cases of IE were found in patients with. Streptococcus mitis, Streptococcus bovis, Streptococcus mutans, Streptococcus anginosus, and Streptococcus sanguinis group streptococci. The HANDOC score thus had a sensitivity of 100% and a specificity of 62% in this cohort.Conclusions: HANDOC has a sensitivity of 100% and a relatively high specificity (62%) also in a prospectively enrolled cohort of patients from another country than its origin. This indicates that HANDOC can be implemented in clinical practice to identify patients with a low risk of IE in whom echocardiography can be omitted.

Risk for Endocarditis in Bacteremia With Streptococcus-Like Bacteria: A Retrospective Population-Based Cohort Study

Background

Many genera and species of Streptococcus-like bacteria (SLB) can cause infective endocarditis (IE), but little is known about the epidemiology of and the risk factors for IE in SLB-bacteremia. The aim of the study was to analyze this in a cohort of patients with SLB-bacteremia, focusing on Abiotrophia, Aerococcus, Gemella, and Granulicatella. We also evaluated whether published scoring systems generated for other Gram-positive bacteria known to cause IE (HANDOC for streptococci and NOVA and DENOVA for enterococci) could be used in SLB bacteremia to decide whether transesophageal echocardiography (TEE) could be omitted.

Methods

Positive blood cultures with SLB were retrieved from population-based registries in Sweden (3.2 million inhabitants), from January 2012 to December 2017. Clinical data were collected from medical records. Risk factors for IE were analyzed and the performances of the scoring systems were calculated.

Results

The incidence of bacteremia with the 4 SLB genera was 30 episodes/1 000 000 population per year, of which Aerococcus contributed with 18. Among 568 episodes of bacteremia, 32 cases of IE were identified (5.6%). Infective endocarditis was most common in bacteremia with Abiotrophia (4 of 19) followed by Granulicatella (9 of 124), Gemella (6 of 87), and Aerococcus (13 of 338). NOVA had 100% sensitivity to identify IE but a low specificity (15%). For HANDOC and DENOVA, the sensitivities were 97% and 91%, respectively, whereas specificities were 85% and 90%, respectively, and numbers needed to screen were 3.6 and 2.8, respectively.

Conclusions

Bacteremia with these SLB is relatively rare, and the decision whether TEE should be performed or not could be based on either HANDOC or DENOVA.

Towards an increased awareness on infective endocarditis in patients with bloodstream infections: a role for multivariate scores?

Collapse

Ineffective Antibiotic Prophylaxis: An Unusual Presentation of Infective Endocarditis with Insights into the Appropriateness of Prophylaxis

The practice of antibiotic prophylaxis for the prevention of infective endocarditis (IE) has undergone a major paradigm shift over the past few decades. From the earlier practice of antibiotic prophylaxis for all patients undergoing dental procedures, since 2006, the American College of Cardiology/American Heart Association (ACC/AHA) guidelines have now narrowed down the indications to use it only in patients at high risk for IE. A true concern for antibiotic resistance remains eminent when used without appropriate indications. Through this case presentation of IE and the associated preceding use of antibiotics, we take this opportunity to explain the appropriateness of prophylaxis in patients from different risk groups. We also shed some light on alternative, effective, and, yet, harmless measures for the prevention of IE in patients at low risk.