Bacterial endocarditis in 4 young infants. Is this complication on the increase?

Bacterial endocarditis in neonatal intensive care

OBJECTIVES

To ascertain the incidence of bacterial endocarditis in a level III neonatal nursery. To document the clinical features, assess survival, and evaluate the role of central venous catheters in neonates with bacterial endocarditis.

METHODOLOGY

Index cases were identified by retrospective review of the echocardiographic records of infants admitted to the neonatal nursery from 1983 to 1995. Data obtained by review of the clinical records of these infants, and case-matched controls.

RESULTS

From January 1983 to December 1995, 12,249 infants were admitted to the Special Care Nursery. Eight infants with endocarditis were identified, an incidence of 0.07%. Presenting symptoms and signs were often vague and nonspecific. Gestation less than 32 weeks, birthweight less than 1500 g, thrombocytopenia and neutropenia or neutrophilia were common features. Infants with endocarditis had a significantly higher Clinical Risk Index for Babies score than those without endocarditis. The tricuspid valve was involved in seven infants, six of whom had a percutaneous central venous catheter in situ before diagnosis. Mitral valve involvement occurred in two infants, neither of whom had central lines inserted. However, compared to infants without endocarditis, the placement of a central venous line was not of statistical significance. Seven of the eight infants survived following prolonged antibiotic therapy.

CONCLUSIONS

Bacterial endocarditis is a rare but serious condition which is usually not fatal. In the premature newborn infant, presenting signs and symptoms are often nonspecific. Endocarditis should therefore be considered in the unwell very low birthweight infant.

Pediatric infective endocarditis in the modern era

Sixty-two cases of endocarditis occurring in children between January 1977 and February 1992 were reviewed and compared with series from the 1970s and early 1980s. Changes in risk factors, pathogens, diagnostic modalities, and outcome were determined. Complex congenital heart disease (22 cases) and unrepaired ventricular septal defect (9 cases) were the most common underlying lesions. A total of 19 children with normal anatomy had endocarditis; 6 had community-acquired infection and 13 had hospital-acquired endocarditis (11 of these 13 children had central venous catheters in place, including 7 premature infants). Echocardiograms revealed vegetations in 25 of 49 patients; 24 of these patients had positive echocardiographic findings on the first study. Echocardiographic findings were most often negative in children with complex cyanotic heart disease. Staphylococcus aureus (39%) was the most common pathogen isolated and was associated with a higher incidence of central nervous system complications (p < 0.0015) and a greater need for surgical intervention (p = 0.01) than were other pathogens. Methicillin-resistant S. aureus (eight cases) and coagulase-negative staphylococci (three cases) emerged as important pathogens but were not associated with increased morbidity or mortality rates. Fungal endocarditis (six cases) had a 67% mortality rate. Overall the mortality rate was 11%. Endocarditis remained undiagnosed in seven seriously ill patients until postmortem examination. This study indicates that, during the past decade, important changes in risk factors, pathogens, and the susceptible population have altered the presentation and management of endocarditis in children.

Aortic root replacement for complicated bacterial endocarditis in an infant

We report the case of a 10-week-old girl with streptococcal aortic valve endocarditis that was resistant to medical management and complicated by aortic insufficiency, congestive heart failure, annular abscess, and a large periaortic pseudoaneurysm. She underwent successful aortic valve and root replacement (with coronary artery reimplantation) utilizing an aortic valve homograft (allograft). The patient recovered completely and was discharged 3 weeks postoperatively. To our knowledge, this is the youngest patient to receive an aortic homograft for bacterial endocarditis and annular abscess.

Infective endocarditis following cardiac catheterization in infancy. A case report and review

A 4.5-month-old infant with transposition of great vessels and large ventricular septal defect developed acute infective endocarditis following cardiac catheterization. Beta-hemolytic streptococcus was recovered from three blood cultures. The infant survived after 6 weeks intravenous antibiotic therapy. The occurrence of infective endocarditis following cardiac catheterization during infancy is briefly reviewed and discussed. The importance of distinguishing febrile episodes of infancy from infective endocarditis and the use of two-dimensional echocardiography for diagnosis is re-emphasized.

Two-dimensional echocardiographic diagnosis of intracardiac masses in infancy

Intracardiac masses in infancy are uncommon. Tumors, thrombi and vegetations of bacterial endocarditis are exceedingly rare in this age group. These masses are seldom diagnosed before the infant's death. In a review of two-dimensional echocardiograms performed from May 1979 to January 1981 on 741 infants less than 2 years of age, intracardiac masses were prospectively identified in 6 patients. All six patients presented with unexplained murmurs associated with either hemodynamic instability, arrhythmias or systemic emboli. One patient had a vegetation from bacterial endocarditis, one had an intracardiac thrombus associated with myocarditis, three had rhabdomyomas (two patients with tuberous sclerosis) and one had a fibro-fatty nodule attached to the eustachian valve. Two-dimensional echocardiography not only was important in the diagnosis, but also provided guidance in the medical and surgical treatment of these patients.

Anti-infective therapy of infectious endocarditis

Because of its high morbidity and mortality, endocarditis will remain an important pediatric problem. Obtaining adequate culture information prior to starting antibiotics to ensure an accurate early diagnosis coupled with aggressive medical and surgical management is likely to give the best outcome. These patients are generally best handled by a team approach with the child's primary physician, cardiologist, infectious disease consultant, and cardiovascular surgeon working in close harmony.