Endocarditis is a serious complication of injection drug use most commonly due to Staphylococcus aureus. We report a case of tricuspid valve polymicrobial bacterial endocarditis in an injection drug user from 3 oral anaerobes: Actinomyces odontolytica, Veillonella species, and Prevotella melaninogenica. The patient was believed to have acquired these organisms due to his habit of licking the needle in order to gauge the strength of the cocaine prior to injection. The patient was successfully treated with a 6-week course of penicillin G and metronidazole. This case demonstrates the importance of a detailed history in designing empiric therapy.
CASE REPORTA 33-year-old white male presented to our hospital with a 2-week history of subjective fevers, chills, and rigors. He also complained of a 20-to 30-lb weight loss, which he attributed to a decrease in appetite as well as to some nausea and vomiting. The patient had previously been seen at another hospital for these symptoms and was prescribed levofloxacin for possible pneumonia. He later returned to that hospital when his symptoms did not improve and a computed tomography (CT) scan of the thorax reportedly showed ''spots on his lungs.'' The patient was given more unknown antibiotics and sent home. Additionally, the patient reported having a dental procedure 6 months previously. His past medical history included diabetes mellitus type 2, gastroesophageal reflux disease, and schizoaffective disorder. He had no history of endocarditis or valvular heart disease. The patient smoked 1.5 packs of cigarettes per day for the past 20 years, consumed alcohol occasionally, and had a history of injection drug use, particularly cocaine. He last used injection cocaine 5 weeks prior to admission.On admission the patient had a temperature of 40.0 1C, a pulse of 80 beats per minute, a respiratory rate of 19 breaths per minute, and a blood pressure of 130/80 mmHg. On physical exam, there was no jugular venous distention and there was a II/VI holosystolic murmur at the lower left sternal border that became louder with inspiration. Lungs were clear to auscultation bilaterally. White blood cell count was 15.1K cells per mL with 90.8% granulocytes and an increase in bands. Cardiac enzymes were normal. Chest radiograph revealed only a slight increased opacity in the right upper lobe of the lung but CT of the thorax showed multiple cavitary lesions in both lungs. The largest lesion was in the left lower lobe and measured 3.2 cm. Transesophageal echocardiogram revealed an echodense mobile structure attached to the anterior leaflet of the tricuspid valve and moderate tricuspid regurgitation. The remainder of the valves was normal.Initially, the patient was treated empirically for endocarditis with vancomycin and ceftriaxone to cover Staphylococcus aureus and Streptococcus. Blood cultures, however, returned positive for Actinomyces odontolytica and Veillonella species. Antimicrobial sensitivities were not identified. The therapy was then changed to penicillin G based on the usual sensitivi...