Aggregatibacter actinomycetemcomitans endocarditis in an adult patient with patent ductus arteriosus.

Introduction: Aggregatibacter (Actinobacillus) actinomycetemcomitans is a commensal bacterial pathogen in the human oral cavity. It can, however, represent the source of local or systemic infections with serious evolution, in particular infective endocarditis. We present a particular case of an adult male patient with infective endocarditis with A. actinomycetemcomitans and patent ductus arteriosus (PDA).

Case report: A 37-year-old patient, chronic ethanol user, is hospitalized for altered general condition, persistent cough, left chest pain, headache and dizziness, symptoms evolving for about 3 weeks. The clinical examination revealed crackling pulmonary rales present basally bilaterally, as well as numerous cavities and dental abscesses. Chest radiography showed mixed left hiliobasal pneumonia. Chest CT depicted pulmonary abscess and two filling defects in the pulmonary artery trunk, possible thrombotic/vegetative images/mediastinal thrombotic/adenopathic images. Broad spectrum antibiotic treatment was initiated. Transthoracic ultrasonography visualized persistence of ductus arteriosus and an echodense formation attached to the lateral wall of the pulmonary artery trunk. Following positive blood cultures for Aggregatibacter actinomycetemcomitans, the diagnosis of infective endocarditis was established and antibiotic treatment was de-escalated to ceftriaxone according to the antibiogram. The clinical course under treatment was slowly favorable, the patient was discharged on request on day 44 with continued treatment at home.

Conclusions: Infective endocarditis caused by Aggregatibacter actinomycetemcomitans should be considered in patients with altered general condition and congenital cardiovascular defects. In the present case, the patient presented two risk factors, namely poor dental hygiene and PDA.