STREPTOCOCCUS-MILLERI BACTEREMIA - REVIEW OF 18 EPISODES

Objective. To study the epidemiological and clinical characteristics o f bacteremia caused by Streptococcus milleri group streptococci (SMG). Methods. Prospective evaluation of all bacteremic episodes with clini cal significance from 1990 to 1995 in two general hospitals. In this s tudy all episodes caused by SMG were analyzed. Results. A total of 905 bacteremic episodes with clinical significance were detected; 18 (1.9 8%) were caused by SMG (0.16/1,000 admissions). The mean age of patien ts were 43 years and the male/female ratio 1.6. Seventeen patients (94 .4%) had some underlying disease: nine patients had diabetes, four wer e parenteral drug abusers, and two had neoplasms. The most common sour ces of bacteremia were intraabdominal in four episodes (two liver absc esses, one subphrenic abscess and one pancreatic pseudocyst), cutaneou s and/or soft tissues in four, surgical wound in two and respiratory i n two; no source was identified in five episodes. Four episodes had a polymicrobial origin. In 13 isolates the identification was at species level (Streptococcus anginosus eight, Streptococcus intermedius four and Streptococcus constellatus one). All strains were susceptible to p enicillin. Six patients (33.3%) required surgery. In ten episodes a fa vorable outcome was recorded, although four patients required surgery. The infection associated mortality rate was 31.2%. The mean age of de ceased patients was higher than for cured patients (62.2 +/- 20.2 vers us 35.3 +/- 20.3; p < 0.05). Conclusions. SMB bacteremia is uncommon. It involved mainly diabetic patients or parenteral drug abusers, commo nly with an intraabdominal suppurative source or in skin or soft tissu es. The mortality rate was high despite surgery in one third of patien ts. Patients with advanced age had a poorer prognosis. All isolates in vestigated were susceptible to penicillin.