Group B streptococcus infections of soft tissue and bone in California adults, 1995–2012

• Published in: Epidemiology and infection 2015-11, Vol.143 (15), p.3343-3350
• Main Authors: SMITH, E. M., KHAN, M. A., REINGOLD, A., WATT, J. P.
• Format: Article
• Language: English
• Subjects: Adolescent; Adult; Age groups; Aged; Aged, 80 and over; Arthritis; Arthritis, Infectious - epidemiology; Arthritis, Infectious - microbiology; California - epidemiology; Cellulitis - epidemiology; Cellulitis - microbiology; Censuses; Child; Child, Preschool; Cohort Studies; Diabetes; Epidemiological Monitoring; Ethnicity; Fatalities; Female; Group B streptococci; Hospitals; Humans; Infant; Infant, Newborn; Male; Medical records; Meningitis; Middle Aged; Original Papers; Osteomyelitis - epidemiology; Osteomyelitis - microbiology; Patients; Population; Public health; Risk factors; Streptococcal Infections - epidemiology; Streptococcal Infections - microbiology; Streptococcus; Streptococcus agalactiae; Streptococcus infections; Surveillance; Trends; Young Adult
• ISSN: 0950-2688; 1469-4409; 1469-4409
• DOI: 10.1017/S0950268815000606

Group B streptococcus (GBS) is an increasing cause of disease in adults. We present long-term trends in incidence of overall infections and identify characteristics of patients with GBS cellulitis, bone and joint infections. Active, population-based surveillance was conducted from 1995–2012 in three California counties and the data were analysed retrospectively. All cases had isolation of GBS from a normally sterile site. Cases of cellulitis were classified based on clinical diagnosis. GBS bone or joint infection was defined as isolation of GBS from a bone or joint or a diagnosis of osteomyelitis or septic arthritis. Medical charts were reviewed for demographic and clinical information. There were 3917 cases of GBS; the incidence of disease increased from 5·8 to 8·3 cases/100 000 persons (P < 0·001) from 1995 to 2012. In adults aged ⩾40 years, the overall incidence of GBS increased from 8·5 to 14·2 cases/100 000 (P < 0·001) persons during the study period. The incidence of cellulitis increased from 1·6 to 3·8 cases/100 000 (P < 0·001), bone infection increased from 0·7 to 2·6 cases/100 000 (P < 0·001), and the incidence of joint infection remained approximately constant at an average rate of 1·0 case/100 000. The highest incidence rates were observed in men, persons aged ⩾80 years, non-Hispanic blacks and Hispanics. Diabetes was the most common underlying condition (51·2% cellulitis cases, 76·3% bone infections, 29·8% joint infections).