en Pediatric Pediatric Original Research Original Research Infective endocarditis is an uncommon heart disease with a variable incidence, mostly related to the ever-increasing development of cardiac surgery and the longer survival of patients with congenital heart disease (CHD). Thirty-seven episodes of infective endocarditis (IE) were evaluated in 36 children (under 15 years of age) admitted to hospitals affiliated to Shiraz University of Medical Sciences during a 10 year period. The mean age was 9.2 years, only one boy was under one year of age and 6 of the children were under 5. Overall, the male to female ratio was 1.46/1, but the ratio was equal in children under 5 years. The frequency of IE was 3 per 1000 pediatric admissions. CHD was the most common underlying disease (27 patients, 73.0%), followed by rheumatic heart disease (RHD) (7 patients, 18.9%). Ventricular septal defect was the most common acyanotic CHD and tetralogy of Fallot was the most common cyanotic CHD. Blood cultures were positive in 54% and vegetations were present in 57.5% by 2-dimensional echocardiography. Streptococcus species (mostly viridans) was the most common infecting micro-organism. The most common site of vegetation was the pulmonary valve, followed by the aortic valve. There were 6 deaths (16.2%) due to different causes. Mortality occurred mostly in culture negatives or in those infected by Gram-negative micro-organisms (p<0.0 1). All mortalities had left-sided vegetations (p<0.001). In conclusion, despite medical and surgical advances, this fatal complication of heart disease remains a significant medical problem. An effective chemoprophylaxis strategy for rheumatic fever and IE will decrease the incidence and outcome of this potentially serious illness. Bacterial endocarditis, Congenital heart disease, Rheumatic heart disease, Children, Developing countries. 251 255 http://mjiri.iums.ac.ir/browse.php?a_code=A-10-298-367&slc_lang=en&sid=1 M BORZOUEE 20031947532846004528 20031947532846004528 Yes From the Department of Pediatrics, Division of Pediatric Cardiology, Shiraz University of Medical Sciences, Shiraz, I.R. Iran F PAYRAVIAN 20031947532846004529 20031947532846004529 No R GHARIB 20031947532846004530 20031947532846004530 No