Infective endocarditis is rare in children and may be caused by normal oral and skin microflora. Staphylococcus and Streptococcus species remain the predominant causative agents, although decreasing rates of Staphylococcal and a growing proportion of Streptococcal infective endocarditis cases have been reported.Reference Day, Gauvreau, Shulman and Newburger 1, Reference Gupta, Sakhuja, McGrath and Asmar 2
Commonly, infective endocarditis in children develops in patients with preexisting CHD, including cases of prosthetic valve endocarditis, less frequently it develops in children with rheumatic heart disease or in children without structural heart disease.Reference Day, Gauvreau, Shulman and Newburger 1 Factors, frequently associated with infective endocarditis in adults, such as degenerative heart disease, are not common in children.
The diagnosis of infective endocarditis may be difficult, if there are no specific features. Difficulties may occur in differential diagnosis with rheumatic carditis in children without history of CHD or acute rheumatic fever.
Case presentation
An 11-year-old girl was admitted to our hospital with fever, weakness and pain in left ankle joint. She had a history of recent tonsillitis/pharyngitis: 2 months before the admission; 2 weeks prior to the admission (received amoxicillin for 5 days). For the past 3–4 years the patient had 2–3 episodes of tonsillitis/pharyngitis per year. Nasal bleedings occurred occasionally during the last 2 years.
She had no history of either CHD or rheumatic fever, although her family history was notable for rheumatic heart disease in a grandmother. Her father reported recurrent episodes of tonsillitis.
Physical examination was remarkable for fever (39°C), lax joints, a high-arched palate. The tonsils were not enlarged, and the heart rate was 146 beats per minute. Cardiac auscultation revealed a mid-systolic click and a grade 2/6 systolic murmur, most prominent over the apex. There were no peripheral stigmata of endocarditis (Osler’s nodes, Roth’s spots, Janeway lesions, splinter hemorrhages).
Laboratory testing revealed anemia, a peripheral white blood cell count of 6,300/µl (77% neutrophils), an erythrocyte sedimentation rate of 33 mm/hr, C-reactive protein 12 mg/dL and antistreptolysin O level of 300 IU (reference value <150 IU). Serum levels of creatine kinase, and lactate dehydrogenase were normal. Rheumatoid factor was negative.
Electrocardiography revealed sinus tachycardia without evidence of ischemia. Doppler-echocardiography detected myxomatous mitral valve with prolapse of both leflets (A2, A3, P2 scallops) and mild mitral regurgitation. The left ventricle was not dilated.
Considering the presence of Jones criteria (carditis, arthralgia, fever, increased level of C-reactive protein, erythrocyte sedimentation rate and episode of recent streptococcal infection) acute rheumatic fever was suspected.
Antibacterial and non-steroid anti-inflammatory therapy was initiated. After three days of treatment, the body temperature normalized, erythrocyte sedimentation rate and C-reactive protein levels decreased.
Repeat echocardiography 10 days after admission revealed moderate mitral regurgitation, dilatation of the left ventricular cavity (left-ventricular end-diastolic diameter 46 mm), and an oscillating structure on anterior mitral leaflet of 6 mm consistent with vegetation. Infective endocarditis was suspected. Urine analysis detected 15–20 red blood cells per high power field. Blood cultures revealed S. gordonii bacteremia, which confirmed the diagnosis of infective endocarditis.
The patient was referred for surgical treatment which was performed at the National center for pediatric cardiology and cardiac surgery. Intraoperative findings showed signs of myxomatous degeneration of the mitral valve leaflets, a vegetation of 7–8 mm was detected at A2–A3 scallops of the anterior mitral leaflet. Vegetations were resected and mitral valve annuloplasty was performed. S. gordonii culture was also obtained from the vegetation.
Postoperative echocardiography showed good biventricular systolic function, traces of mitral regurgitation, no pericardial or pleural effusion.
Discussion
Herein we report a unique case of infective endocarditis in a child. In this case the differential diagnosis of rheumatic carditis and infective endocarditis was difficult as the patient met the Jones criteria for acute rheumatic fever. Besides, patient has a family history of rheumatic heart disease. Ukraine is a low-risk country for acute rheumatic fever with a decreasing prevalence of rheumatic heart disease,Reference Boyarchuk, Komorovsky, Kovalchuk and Denefil 3 and cases of these diseases occur.Reference Boyarchuk, Hariyan and Kovalchuk 4
For diagnosis of infective endocarditis in children the modified Duke criteria are currently used,Reference Li, Sexton and Mick 5 although their specificity has been questioned.Reference Baltimore, Gewitz and Baddour 6
Endocardial involvement (valvulitis) is also a characteristic of acute rheumatic fever. There was no previous history of CHD or any other predisposing heart condition. Previous history of systolic murmur was unclear. Only microscopic hematuria as a sign of glomerulonephritis was interpreted as an immunologic phenomenon. On the first days after admission to the hospital, our patient met one questionable major criterion (valvulitis) and two small criteria (fever, glomerulonephritis). Extracardiac manifestations of infective endocarditis are considerably less common in children than in adults,Reference Baltimore, Gewitz and Baddour 6 although nasal bleedings were reported in our patient, they were occurring during the last two years. The diagnosis of infective endocarditis was deemed as “possible” according to the modified Duke criteria.
Vegetation on the mitral valve and positive blood culture were the criteria which permitted to diagnose “definite” infective endocarditis and to differentiate it from rheumatic valvulitis.
Another feature of this case is that infective endocarditis developed in child with a previously undiagnosed Barlow’s disease. Barlow’s disease is prominent form of degenerative mitral valve disease characterized by excessive myxomatous tissue proliferation resulting in thick, spongy leaflets, bileaflet prolapse and/or billowing, hooding, annular dilatation.Reference Anyanwu and Adams 7 The described patient had lean body stature, lax joints, high-arched palate. Unfortunately, we were not able to obtain a clear history of a previous heart murmur in this patient. The patient’s mother reported that only two weeks before the admission the primary care pediatrician mentioned a “heart murmur”.
Typically patients with Barlow’s disease are young females, and most cases have been described in adults.Reference Tomšič, Hiemstra and Bissessar 8 These patients are presumably at elevated risk for subacute bacterial endocarditis, and rheumatic heart disease, although degenerative heart disease is not a common risk factor in children.
Thus, the patient had an underlying condition (Barlow’s disease) for development of either infective endocarditis or rheumatic process. S. gordonii was a causative agents of infective endocarditis in our patient. It belongs to the Viridians group streptococci, S. sanguinis subclass.Reference Doern and Burnham 9 As part of the normal oral microflora, S. gordonii is involved in dental plaque formation and may be associated with dental caries. Ability to adhere to and induce the aggregation of platelets is thought to be a virulent trait of S. gordonii.Reference Plummer and Douglas 10
Our patient did not undergo any dental procedures over the last year, but the child’s mother reported poor oral hygiene in her daughter. American Heart Association guidelines outline importance of oral health in prevention of infective endocarditis.Reference Baltimore, Gewitz and Baddour 6
Conclusion
Differential diagnosis of rheumatic carditis and infective endocarditis may be difficult when the patient meets the Jones criteria. Vegetation on the mitral valve and positive blood culture allows diagnosing “definite” infective endocarditis. Blood culture and serial echocardiography may be recommended in all cases of suspected valvulitis. Barlow’s disease may be considered as a risk factor for infective endocarditis in children as well.
Author ORCIDs
Roman R. Komorovsky 0000-0002-0288-4132
Financial Support
None.
Acknowledgment
The authors acknowledge the input of the colleagues from the National Center for Pediatric Cardiology and Cardiac Surgery (Kyiv, Ukraine) who contributed to the diagnosis and performed surgery on the reported patient.
Conflicts of Interest
This research received no specific grant from any funding agency or from commercial or not-for-profit sectors.
Ethical Standards
The authors assert that all procedures contributing to this work comply with the ethical standards of the relevant national guidelines on human medical regulations and with the Helsinki Declaration of 1975, as revised in 2008, and has been approved by the ethical committee of I.Horbachevsky Ternopil State Medical University.
