[Septicemia due to Streptococcus milleri with pulmonary complications]

Streptococcus milleri can occasionally cause serious septicemia, that is often complicated by abscesses, particularly pulmonary.

A 12.5 year-old boy was admitted because he had suffered from fever for 6 days. He also had headache, diffuse abdominal pain, chills and a cough. Laboratory investigations showed leukocytes: 9,300/mm3 (PMN: 6,700/mm3; lymphocytes: 1,400/mm3; monocytes: 1,200/mm3); hemoglobin: 12.5 g/dl; platelets: 106,000/mm3; sedimentation rate: 120 mm at 1 hour; blood fibrinogen: 5.6 g/l and C-reactive protein: 193 mg/l. His chest X-rays was normal. Four blood cultures showed Streptococcus milleri. The patient was given amoxicillin (150 mg/kg/d) plus gentamicin (3 mg/kg/d). Two foci of dental infection were found and treated by tooth extraction. Blood cultures remained positive 2, 3 and 6 days after onset of treatment and a second chest X-rays and CT scan showed several bilateral pulmonary abscesses. Cardiac ultrasonographs showed no valvular vegetations. The patient was then given ceftriaxone (100 mg/kg/d) plus rifampicin (20 mg/kg/d) and netilmicin (6 mg/kg/d). Blood culture was negative two days later, but the fever persisted and ceftriaxone was then successfully replaced by vancomycin (40 mg/kg/d) for three weeks.

There are several reasons for the apparent resistance to treatment of this potentially severe infection; they are discussed by the authors.