title: Group B streptococcus infections of soft tissue and bone in California adults, 1995-2012.
abstract: 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).
authors.affiliation: California Emerging Infections Program,Oakland,CA,USA.
authors.forename: E M
authors.initials: EM
authors.lastname: Smith
authors.affiliation: California Emerging Infections Program,Oakland,CA,USA.
authors.forename: M A
authors.initials: MA
authors.lastname: Khan
authors.affiliation: California Emerging Infections Program,Oakland,CA,USA.
authors.forename: A
authors.initials: A
authors.lastname: Reingold
authors.affiliation: California Emerging Infections Program,Oakland,CA,USA.
authors.forename: J P
authors.initials: JP
authors.lastname: Watt
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001170:Arthritis, Infectious / Q000453:epidemiology* / Q000382:microbiology; D002140:California / Q000453:epidemiology; D002481:Cellulitis / Q000453:epidemiology* / Q000382:microbiology; D002648:Child; D002675:Child, Preschool; D015331:Cohort Studies; D062665:Epidemiological Monitoring; D005260:Female; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D008875:Middle Aged; D010019:Osteomyelitis / Q000453:epidemiology* / Q000382:microbiology; D013290:Streptococcal Infections / Q000453:epidemiology* / Q000382:microbiology; D013292:Streptococcus agalactiae; D055815:Young Adult
keywords: Bone infections; epidemiology; joint infection; skin infections; streptococcal infections