Group B Streptococcal Bacteremia in Adults in the 21st Century

Abstract

Group B Streptococcus (GBS) remains a major pathogen in adult patients, and bacteremia from GBS is common. We reviewed the medical records of all adults (≥16 years of age) with group B streptococcal bacteremia (GBSB) at our institution from July 1, 2002, to December 31, 2011, and report the incidence, epidemiology, source of infection, comorbid conditions, and results of therapy. These data are compared with prior studies of adults with GBSB. There were 132 episodes of GBSB in 126 patients. Six patients had recurrent GBSB. There was a mean of 13.2 episodes per year: 73 episodes (55.3%) in women and 59 episodes (44.7%) in men. The patients’ ages ranged from 16 to 97 years (mean, 64.4 years). Common sources of infection were skin and soft tissue (38 episodes [28.8%]), septic arthritis (13 episodes [9.8%]), infective endocarditis (13 episodes [9.8%]), pneumonia (11 episodes [8.3%]), osteomyelitis (10 episodes [7.6%]), pyelonephritis (9 episodes [6.8%]). Seventeen patients (12.9%) had primary bacteremia. The most common underlying illnesses were diabetes mellitus, hypertension, coronary artery disease, and congestive heart failure. The mean Charlson comorbidity index was 2.41, with an age-adjusted index of 4.11. Seventeen of 126 known patients died (13.4% mortality rate). Detailed antimicrobial treatment data were available for 105 of our patients, and length of treatment for our patients is reviewed. Group B streptococcal bacteremia is common in adult patients in the 21st century with considerable morbidity and a 13.4% mortality rate despite uniformly appropriate antimicrobial therapy. Diabetes mellitus is the most commonly identifiable comorbid condition and remains a harbinger of group B streptococcal infection/bacteremia. All of our GBS strains remained exquisitely sensitive to penicillin G, ampicillin, cefotaxime, and ceftriaxone throughout the 10-year study period and remain effective first-line therapeutic agents.