The clinical spectrum of disease for the Streptococcus anginosus group (SAG) differs from other viridans streptococci with a tendency for causing pyogenic infections. Subsequent to its discovery in 1956, a handful of cases reports and series have been published. However, the overall data is based on relatively small numbers of patients. In order to help expand the published data about the SAG, we completed a retrospective analysis of SAG infections at our tertiary care center from 2007 to 2011 to further elucidate the spectra of disease, antimicrobial susceptibility, and clinical sequelae of these organisms.
All SAG infections at the State University of New York in Syracuse were retrospectively evaluated from January 2007 to December 2011. Patient demographic information, co-morbid conditions, and clinical elements of their infection (including site of infection, management, antibiotics susceptibilities, and length of stay) were analyzed.
332 cases over the 5-year study period were evaluated. The majority of cases were male (59%) with an average age of 47. Approximately half had pre-morbid conditions with the most common being hypertension (31%) and diabetes (25%). Most cases were skin and soft tissue infections (72%) while 14% had solid organ involvement. Bony infection were mostly odontogenic. Of the 18 patients with bacteremia (6%) none were found to have endocarditis. 70% of infections were polymicrobial with various Enterobacteriaceae and gram negative anaerobes as the most common co-pathogens. Average length of stay was just under 9 days and increased with depth of infection. All isolates were penicillin susceptible except for one while 45 isolates were intermediately susceptible. 82% of patients were treated with combined surgery and antibiotic therapy.
Streptococcus anginosus group organisms cause pyogenic infections across all ages. Treatment often requires combined surgical drainage and antibiotic therapy. Beta-lactams remain the drugs of choice with very little resistance. Infections are often polymicrobial (gram negatives and anaerobes) necessitating a broader spectrum of therapy. Mortality is typically low but does increase with the incidence of bacteremia.
T. Endy, None
T. Calden Shargnoe, None
B. White, None