Infective endocarditis in Swedish children. I. Incidence, etiology, underlying factors and port of entry of infection

Incidence of infective endocarditis caused by viridans group streptococci in Sweden - effect of cessation of antibiotic prophylaxis in dentistry for risk individuals

Introduction

In October 2012, the Swedish Medical Products Agency published new recommendations for the cessation of prophylactic antibiotics in dentistry for the prevention of infective endocarditis (IE). Previously, 2 g of amoxicillin per os would be administered 1 h before invasive dental procedures to patients with valve prosthesis, complicated heart valve disease, and to those with previous endocarditis.

Objectives

The aim of this study was to evaluate whether the total incidence of IE caused by oral viridans group streptococci (VGS) or IE caused by staphylococci, increased in Sweden after the introduction of the new recommendations.

Methods

The incidence of IE in Sweden before and after October 2012 was calculated and compared using an interrupted time series analysis. Separate analyses were conducted for the total incidence of IE, and IE caused by VGS or Staphylococcus aureus. Cases of IE were identified using the Swedish national registry of IE, which has existed since 1995 and contains data from all Swedish hospital clinics specialising in infectious disease. All cases with hospital admission date from the 1^st of Jan 2008, to the 31^st of Dec 2017 were included. The incidence calculations were corrected for annual changes in population size using data from the Swedish government agency Statistics Sweden.

Results

The results show no statistically significant increase in the slope of the trend line of the total incidence of IE, IE caused by VGS or S. aureus in the Swedish general population after October 2012, compared to before.

Conclusion

The results suggest that the recommended cessation of prophylactic antibiotics for the prevention of IE in dentistry has not led to an increased incidence of IE caused by oral streptococci among the Swedish population.

Infective endocarditis in congenital heart disease

Congenital heart disease (CHD) has become the leading risk factor for pediatric infective endocarditis (IE) in developed countries after the decline of rheumatic heart disease. Advances in catheter- and surgery-based cardiac interventions have rendered almost all types of CHD amenable to complete correction or at least palliation. Patient survival has increased, and a new patient population, referred to as adult CHD (ACHD) patients, has emerged. Implanted prosthetic material paves the way for cardiovascular device-related infections, but studies on the management of CHD-associated IE in the era of cardiovascular devices are scarce. The types of heart malformation (unrepaired, repaired, palliated) substantially differ in their lifetime risks for IE. Streptococci and staphylococci are the predominant pathogens. Right-sided IE is more frequently seen in patients with CHD. Relevant comorbidity caused by cardiac and extracardiac episode-related complications is high. Transesophageal echocardiography is recommended for more precise visualization of vegetations, especially in complex type of CHD in ACHD patients. Antimicrobial therapy and surgical management of IE remain challenging, but outcome of CHD-associated IE from the neonate to the adult is better than in other forms of IE.

CONCLUSION

Primary prevention of IE is vital and includes good dental health and skin hygiene; antibiotic prophylaxis is indicated only in high-risk patients undergoing oral mucosal procedures.

Pediatric infective endocarditis: Has Staphylococcus aureus overtaken viridans group streptococci as the predominant etiological agent?

BACKGROUND

Viridans group streptococci (VGS) have traditionally been the most common etiological agents of infective endocarditis (IE). Advances in cardiovascular surgery and the increasing use of long-term central venous catheters may have altered the epidemiology of pediatric IE.

METHODS

A chart review of children younger than 17 years of age with IE was completed at the Stollery Children's Hospital (Edmonton, Alberta) between 1985 and 2004. The literature was reviewed to look for changes over time in the most common etiological agents of pediatric IE.

RESULTS

There were 31 cases of definite IE and nine cases of possible IE at the Stollery Children's Hospital, 19 of which were nosocomial. Thirty cases (75%) had congenital heart disease. The etiological agents were Staphylocccus aureus (n=16), VGS (n=5), coagulase-negative staphylococci (n=3), enterococcus (n=3), other streptococci (n=8), Enterobacter cloacae (n=1) and Stenotrophomonas maltophilia (n=1), while three cases were culture negative. Two deaths were due to S aureus IE. Review of the literature identified an increasing number of case series in which S aureus was the predominant etiological agent, but VGS still predominated in some recent series.

CONCLUSION

Congenital heart disease remains the primary risk factor for pediatric IE. Prospective population-based studies are required to determine whether S aureus has become the predominant pathogen.

A cost-effectiveness analysis of bacterial endocarditis prophylaxis for febrile children who have cardiac lesions and undergo urinary catheterization in the emergency department

OBJECTIVE

To prevent bacterial endocarditis (BE) in those at risk, the American Heart Association recommends antibiotics for patients who have a known urinary tract infection and are about to undergo urinary catheterization (UC). In young children who have cardiac lesions and undergo UC for fever without a source, the problem with prophylaxis only in the presence of infected urine is that the presence of urinary tract infection is unknown before testing. This study was conducted to determine the cost-effectiveness of BE prophylaxis before UC in febrile children aged 0-24 months with moderate-risk cardiac lesions.

METHODS

We evaluated the cost-effectiveness of BE prophylaxis compared with no prophylaxis from the societal perspective. Clinical outcomes were based on BE incidence and quality-adjusted life years (QALYs). Probabilities were derived from the medical literature. Costs were derived from national and local sources in US dollars for the reference year 2000, using a discount rate of 3%.

RESULTS

On the basis of the analysis, prophylaxis prevents 7 BE cases per 1 million children treated. When antibiotic-associated deaths were included, the no-prophylaxis strategy was more effective and less costly than the prophylaxis strategy. When antibiotic-associated deaths were excluded, amoxicillin cost 10 million dollars per QALY gained and 70 million dollars per case prevented. For vancomycin, it was 13 million dollars per QALY gained and 95 million dollars per case prevented. The results were robust to variations in the prophylactic efficacy of antibiotics, incidence of bacteremia after UC, incidence of BE after bacteremia, and costs associated with BE prophylaxis and treatment.

CONCLUSION

In the emergency department, BE prophylaxis before UC in febrile children who are aged 0 to 24 months and have moderate-risk cardiac lesions is not a cost-effective use of health care resources.

Infective endocarditis in infants and children

Due to changing characteristics of infective endocarditis in the past two decades, we, retrospectively analysed 28 cases of infective endocarditis in children of age less than 15 years at Sher-i-Kashmir Institute of Medical Sciences, Soura, Srinagar from December, 1983 to November, 1993. The incidence of disease was observed as 1.5 cases/1000 children admitted with a M:F ratio of 2:1. Three patients were of age less than 2 years (group I) as 25 were above 2 years of age (group II). The two groups had significant difference in portal of entry of infection, infective microorganisms, echocardiography and prognosis. Congenital heart disease was the commonest underlying cardiac lesion in 24 (85.71%) patients. Portal of entry of infection was apparent in 35.71% only; dental route being more frequent in group II. Streptococcus viridans (in 9 cases) followed by staphylococcus aureus (in 4 cases) were the two common organisms isolated. Patients were treated, for a period of 4-6 weeks with a over all mortality rate of 25%. Factors associated with poor prognosis were age < 2 years, staphylococcal infection ad negative blood cultures. Heart failure resistant to medical therapy was a leading cause of death.

Infective endocarditis caused by an unusual gram-negative rod, Rahnella aquatilis

An 11-month-old girl with congenital heart disease developed infective endocarditis. Blood cultures revealed an unusual gram-negative rod, Rahnella aquatilis. The patient was successfully treated with a combination of netilmicin and ceftazidime. This is the first case report of infective endocarditis caused by this organism. R. aquatilis should be recognized as a clinical pathogen capable of causing life-threatening infection in children and adults.

Epidemiologic aspects of infective endocarditis in an urban population. A 5-year prospective study

A prospective study of the epidemiology of infective endocarditis (IE) in a well-defined urban population of 428,000 inhabitants during a 5-year period was carried out. All patients were treated in the same institution, and history, diagnostic procedures, and treatment were standardized. Of 233 consecutive suspected episodes of IE, 127 fulfilled the modified von Reyn criteria. After patients not living in the defined area were excluded, 99 episodes in 90 patients were analyzed in the epidemiologic part of the study. Of these, 33 episodes were definite endocarditis, verified by surgery or autopsy; 35 probable; and 31 possible endocarditis episodes. Another 34 episodes were found retrospectively and are included in the incidence calculation. The crude incidence was calculated to be 6.2/100,000 inhabitants per year, which is high compared to earlier studies. Adjusted to the population of Sweden, the incidence was 5.9/100,000 inhabitants per year. The annual incidence was higher for women, 6.6/100,000, than for men, 5.8/100,000. In the oldest age-group (80-89 years) the annual incidence was 22/100,000 in the prospective study and 30/100,000 if retrospective cases were included. Contrary to almost all other studies, we did not find a male predominance among our cases. Only 7% of patients were intravenous drug abusers, and 15% had a prosthetic valve. The most common bacteria were methicillin-susceptible Staphylococcus aureus (31%) and alpha-streptococci (28%); 12% of episodes were culture negative. The mortality from IE in the population was 1.4/100,000 inhabitants per year. A higher-than-expected incidence of IE was found, especially among older patients and women.

Spectrum of infective endocarditis during infancy and childhood: 20-year review

The medical records of the 29 patients under 18 years of age with infective endocarditis (IE) seen over a 20-year period by our department were reviewed to provide an overview of the spectrum of IE during infancy and childhood. None of the 29 patients had had previous cardiovascular surgery. The mean age at onset of IE was 7 years 2 months; 3 patients (10%) were under 2 years of age at onset. One patient during the early years died following 4 months of treatment with various antibiotics. Three patients underwent urgent surgery, and 17 patients with healed IE had elective surgery. All of the 20 patients who were operated on survived. The remaining 8 were followed with medical treatment alone. Positive blood cultures were obtained from 24 (83%) patients, and streptococci were still commonly found (38%). Ventricular septal defect (VSD) accounted for 66% of underlying heart diseases and rheumatic heart diseases for 14%. Vegetations were detected in 12 (67%) of 18 patients observed by echocardiography. Among these 12 patients, 1 with VSD underwent urgent tricuspid valve replacement and VSD closure because of worsening congestive heart failure due to progressive tricuspid regurgitation. Echocardiography identifies patients at high risk with IE, though the presence of a vegetation on echocardiography does not necessarily of itself dictate surgical intervention.

Infective endocarditis in children: profile in a developing country

With the object of studying the profile of infective endocarditis in Indian children younger than 16 years of age, a retrospective study of 37 patients with infective endocarditis admitted to this hospital between January 1984 and December 1990 was carried out. There were 26 boys and 11 girls (aged 2-16 years (mean (SD) 10.3 (3.8)). Eighteen (48.6%) patients had underlying congenital heart disease, 13 (35.1%) had associated rheumatic heart disease whilst the remaining six had no pre-existing heart disease. All six patients with a normal heart and infective endocarditis had preceding extra-cardiac bacterial illnesses (epididymitis and orchitis in one, pneumonia in five). Blood cultures were positive in only 16 (43.2%): Staphylococcus aureus was grown in nine, Streptococcus viridans in six and Candida albicans in one. Sixteen (43.2%) of the 37 patients died owing to worsening cardiovascular haemodynamics, uncontrolled septicaemia and our inability to offer emergency surgery. The profile of infective endocarditis in developing countries is different from that in Europe and the United States of America, and the disease carries a very high mortality.

Surgical management of infective endocarditis in children

Infective endocarditis occurs infrequently in the general pediatric population, occurring mostly in patients with congenital heart disease. This study reviews our surgical experience with infective endocarditis based on a policy of aggressive intervention, conservative operative debridement, and creative reconstruction options using pericardium and prosthetic heart valves. From 1982 to 1989, 16 patients, 3 weeks to 16 years of age, underwent 19 intracardiac operations for infective endocarditis therapy at Kosair Children's Hospital. Eight (42%) were for resection of vegetations alone; an additional 11 operations (58%) involved more extensive debridements requiring either valve replacement or valvuloplasty using pericardium for exclusion of an abscess cavity, closure of a fistula, or for valve repair. Operative mortality was 25% (4 patients) and related to preoperative disease severity. There was one late death. Offending organisms included Staphylococcus species (31%), Haemophilus influenzae (13%), pneumococcus (5%), gram-negative organisms (13%), and Candida (13%); no organism grew on culture in 25%. We conclude that aggressive surgical exploration in patients with infective endocarditis is indicated and often requires resection of vegetations alone. More extensive procedures should preserve as much valvular tissue as possible. Pericardium is useful for reconstruction after debridement.

Bacterial endocarditis in children: trends in its diagnosis, course, and prognosis

In a population-based study of 41 children with bacterial endocarditis (BE), diagnosed in the period 1970 through 1989 in eastern Denmark, we analyzed trends in the diagnosis of BE and in mortality, and searched for possible prognostic factors. During this period the delay in diagnosis from first symptom to treatment did not change, but the delay from admission to treatment was significantly prolonged from 0 to 3 days, despite the introduction of echocardiography (ECHO). There was a significant improvement in the prognosis, the mortality rate having decreased from 40 to 0% [95% confidence limits: 12-74 vs. 0-26 (0.01 less than p less than 0.02)]. The improved prognosis was not explained by changes in the etiology or pattern of antibiotic resistance and may reflect a milder course of BE in children. Children with "mild anomalies"--such as bicuspid aortic valve (n = 5), coarctation of the aorta (n = 2), and prolapse of the mitral valve (n = 2)--had a significantly poorer prognosis than children with other forms of congenital heart disease (CHD) (p = 0.004), a reminder of the importance of suspecting BE in all children with unexplained long-lasting or intermittent fever, because some may have unrecognized "mild" CHD.

Successful medical treatment of presumed Candida endocarditis in critically ill infants

Few infants have been reported who survived fungal endocarditis; all have required both surgical and intensive antifungal therapy. We describe three infants, two weighing less than 1000 gm, who survived Candida endocarditis without surgery. Two had Candida parapsilosis, an agent not previously reported as a cause of neonatal endocarditis. All three infants were treated with amphotericin B and 5-flucytosine. Despite administration of 44, 38, and 48 mg/kg amphotericin B, respectively, no nephrotoxicity was noted; 5-flucytosine therapy was stopped in one infant because of thrombocytopenia. One infant died of an unrelated cause 6 months later; there was no evidence of Candida or endocarditis at autopsy. The other two infants are thriving 2 and 3 years after the completion of antifungal therapy; no remaining evidence of endocarditis is present on echocardiography. We conclude that antifungal therapy without surgery is an option for Candida endocarditis in critically ill infants.

Infectious endocarditis in children

With the object of analyzing current characteristics of infectious endocarditis (IE) in children, we carried out a retrospective study of 23 cases of IE in children under 15 years of age seen at the Hospital Ramón y Cajal in Madrid (Spain) between 1977 and 1985. The incidence was high (1.3 cases per 1000 children admitted). The male/female ratio was 2:1. Eight patients were under 2 years of age and 15 over 2 years, the majority being adolescents. The two groups presented marked etiological and prognostic differences. Congenital heart disease was the predisposing factor in 20 of the 23 cases. Streptococcus viridans (nine cases) and Staphylococcus aureus (eight cases) were the most frequent organisms. Fourteen cases were on a native valve and nine were secondary (seven of these on prosthetic patches). In spite of advances in therapy, IE continues to be a severe illness: the mortality rate in our series was 26%. Factors associated with a poor prognosis were: age less than 2 years, Staphylococcus aureus as the causative agent, and the presence of prosthetic material.

Follow-up study on children with infective endocarditis

A follow-up study on 36 children having had infective endocarditis during the time period 1971-80 was performed. All answered a questionnaire and 33 underwent a complete non-invasive cardiac examination including exercise test. The study comprised 406 patient years. During this time there were four late deaths and three recurrent attacks of endocarditis. Seventeen (47%) took prophylactic antibiotics. Two patients had been operated on because of the initial infection and another five had developed intracardiac sequelae. An ability index given to each patient before the infection and at the follow-up showed that as a group these patients were doing well.

Adherence of alpha-hemolytic streptococci to human endocardial, endothelial and buccal cells

Human buccal, endothelial and endocardial cells were prepared and the adherence of different bacteria to these cells was tested in vitro. Buccal cells were scraped off immediately before use in the adherence tests. Endothelial and endocardial cells were prepared from human umbilical vein and human heart valves by using collagenase, and cultured in cell culture medium. Seventeen different bacteria were used in the adherence tests; ten strains of alpha-hemolytic streptococci, five from children with infective endocarditis (IE) and five from healthy carriers, two S. aureus, two N. meningitidis, two N. gonorrhoeae and one E. coli. The five alpha-hemolytic streptococcal strains from patients with IE showed significantly higher adherence values than those from healthy carries as well as in comparison with the remaining seven bacteria. The difference in adherence might be an expression for different bacteria surface properties. These differences might be important in explaining the infective mechanism in infective endocarditis.

Infective endocarditis in Swedish children. II. Location, major complications, laboratory findings, delay of treatment, treatment and outcome

66 cases of infective endocarditis (IE) during 1971-1980 were studied. The infection was in most cases located to the mitral or aortic valve. Major complications were found in 43 children. In 17 children there was a long history of infection for which medical consultation had previously been sought prior to correct diagnosis. Antibiotics were administered to 60 children, in 58 intravenously while 2 received oral therapy only. Acute surgical intervention was necessary in six children and three of these children died. In all, 15 (23%) children died as a consequence of the infection.