Pneumococcal endocarditis in infants and children

We report a case of pediatric pneumococcal endocarditis (PPE) and review the English language literature on this disease. Thirty-two cases of PPE were identified since 1900. One-fourth of these were reported since 1990. Clinical features differed from adult cases, with mitral valve involvement being more frequent and Osler's triad rarely present in children. Congenital heart disease was the only identifiable risk factor. Medical therapy alone resulted in a high mortality rate that was improved in the group of patients receiving combined medical and surgical interventions. PPE is a rare infection that has been reported more frequently in the era of increasing antibiotic resistance. Unlike typical "subacute" endocarditis caused by viridans streptococci, PPE is an aggressive disease with a high mortality rate. Early surgical intervention might improve survival.     

Pneumococcal endocarditis in a previously healthy 17-month-old boy

Invasive pneumococcal infection is a severe disease and its incidence may be increasing. Endocarditis due to Streptococcus pneumoniae is uncommon, particularly in children without risk factors. Etiologic diagnosis is difficult when cultures are negative. We report the case of a previously healthy, 17-month-old boy not vaccinated against pneumococcus who, during the course of pneumonia treated with beta-lactam antibiotics, developed cardiorespiratory deterioration and heart murmur. Mitral valve vegetation was identified by transthoracic echocardiography. Endocarditis was diagnosed and new antibiotics were given for 6 weeks (cefotaxime, gentamycin and vancomycin). Cultures were negative. Because of lack of improvement, prosthetic mitral replacement was indicated. S. pneumoniae was identified by polymerase chain reaction (PCR) in the pathological specimen. Outcome was favorable, and the patient remained symptom-free after 6 months of follow-up. The possibility of endocarditis as an invasive pneumococcal infection should be considered in children without risk factors. PCR is a useful technique to establish the etiology when cultures are negative.     

Pneumococcal vaccination of children

Streptococcus pneumoniae is the most frequent cause of invasive bacterial infection in children younger than 2 years of age, reaching a peak incidence at 6 to 12 months of age. Pneumococci also cause many cases of pneumonia, sinusitis, and otitis media. Incidence rates of invasive infection in children with sickle cell disease, acquired or congenital splenectomy, or human immunodeficiency virus infection are 20- to 100-fold higher than are those of healthy children during the first 5 years of life. Other healthy children, such as those of American Indian, Native Alaskan, or African American descent, also have high rates of invasive infection, and those children enrolled in out-of-home care may have modestly increased risks. Pneumococcal polysaccharide polyvalent vaccines have been available for more than 2 decades but are limited in their usefulness for children because of their inability to induce protective antibody responses in children younger than 2 years of age and lack of immunologic memory. In contrast, pneumococcal protein conjugate vaccines induce presumptive protective responses in infants younger than 6 months, and immunologic memory further enhances responses after booster doses are given. Currently, a single heptavalent pneumococcal protein conjugate vaccine is licensed for use in the United States and is recommended for routine administration to all children, beginning at 2 months of age. It also is recommended for children between 24 and 59 months of age who are at high risk of acquiring invasive disease.     

Infective endocarditis in children

Between January 1977 and December 1982, 34 patients below the age of 20 years (age range 1.9–20 yr, mean 12.3 years) were treated for 38 episodes of infective endocarditis (IE). Twenty three patients (68%) had rheumatic heart disease (RHD), while 11 had congenital heart disease (CHD). Echocardiography was diagnostic of IE in 10 of 12 patients (83%) in whom it was performed. Blood culture was positive in only 15 instances (40%), staphylococcus being the most common organism isolated. Twenty eight (74%) episodes of IE resulted in a cure by medical treatment. Ten patients (26%) died during the medical treatment 9(90%) because of relentless congestive heart failure and 1(10%) due to cerebral embolism. Infective endocarditis in children is an important therapeutic problem. Culture negative endocarditis is frequent in our setting.     

Infectious endocarditis in children

Summary 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 21. 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) andStaphylococcus 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.     

Pneumococcal revaccination of splenectomized children

Forty-three Danish splenectomized children received a single subcutaneous dose of a 14-valent pneumococcal vaccine (Pneumovax 23; Merck). Blood samples were taken before, 4 weeks after and 5 years after vaccination. Total pneumococcal antibody concentrations as well as antibodies against each of the 14 pneumococcal capsular polysaccharide antigens were measured by the enzyme-linked immunosorbent assay method. Depending on the pneumococcal antibody status 5 years after primary vaccination, the children were either revaccinated with a new 23-valent pneumococcal vaccine or scheduled for reexamination later. The antibody concentrations found 5 years after vaccination showed a strong correlation with the prevaccination antibody concentrations. Revaccination of children with low antibody concentrations 5 years after primary vaccination is safe, is without significant side effects and leads to a satisfactory antibody response.     

Pneumococcal infections in splenectomized children are preventable

Through the Danish National Patient Registry we identified all children 0-15 years old who had been splenectomized during the period 1979-87 and all children of the same age who, during the same period of time, had been admitted to a hospital because of either meningitis or bacteraemia caused by Streptococcus pneumoniae. We wanted to see whether any of the splenectomized children had developed invasive pneumococcal infection during the observation period. A similar Danish study covering the period 1969-78, when pneumococcal vaccine was not available, has already been published (3). Four per cent of the children splenectomized during that period developed invasive pneumococcal infection in contrast to none of the children splenectomized and vaccinated during the period 1979-87. Since 1982 antibiotic treatment of splenectomized patients running a fever has been recommended, and we show that the program of pneumococcal vaccination and defined antibiotic prophylaxis has been highly efficacious in preventing post-splenectomy infections in children.     

Pneumococcal infections in children: hemolytic-uremic syndrome

By the example of a case-report diagnostic and therapeutic features of the haemolytic-uraemic syndrome are discussed within the frame of infections by pneumococci. In case of infections by pneumococci but also of those ones caused by other bacteria or viruses neuraminidase may be set free, that on its part may lead to an enzyme-induced haemolysis and in some cases also to a damage of other cell systems. In case of an active share of the kidney a haemolytic-uraemic syndrome may be the consequence.     

Infective endocarditis in children.

IE in children is associated primarily with underlying congenital structural heart lesions, predominantly septal defects or complex lesions involving septal defects. During the past 20 years IE associated with rheumatic heart disease has declined to a negligible number. Recently nosocomial catheter-associated bacteremia has been associated with the development of IE, especially in infants. Streptococci are most frequently associated with IE involving natural valves. Although streptococci have also been implicated in cases of IE associated with previous surgery or catheter-related infection, staphylococci, Gram-negative rod species and multiple infecting species are also encountered in this setting. Because infection can often be managed medically, removal of grafts or prosthetic valves is not necessary unless clinical or microbiologic failure occurs. Penicillin with or without an aminoglycoside is the regimen for most community-acquired streptococcal IE. A penicillinase-resistant beta-lactam generally is substituted for penicillin in IE caused by an unknown agent and is used in cases of staphylococcal IE. For IE caused by resistant staphylococci, vancomycin is the alternative agent. Currently there is limited information on the efficacy of alternative agents for treating IE caused by enterococci or staphylococci with multiple antibiotic resistance.