Epidemiology of Invasive Group B Streptococcal Infections Among Nonpregnant Adults in the United States, 2008-2016

Abstract

Streptococcus (GBS) is an important cause of invasive bacterial disease. Previous studies have shown a substantial and increasing burden of GBS infections among nonpregnant adults, particularly older adults and those with underlying medical conditions. OBJECTIVE To update trends of invasive GBS disease among US adults using population-based surveillance data. DESIGN, SETTING, AND PARTICIPANTS In this population-based surveillance study, a case was defined as isolation of GBS from a sterile site between January 1, 2008, and December 31, 2016. Demographic and clinical data were abstracted from medical records. Rates were calculated using US Census data. Antimicrobial susceptibility testing and serotyping were performed on a subset of isolates. Case patients were residents of 1 of 10 catchment areas of the Active Bacterial Core surveillance (ABCs) network, representing approximately 11.5% of the US adult population. Patients were included in the study if they were nonpregnant, were 18 years or older, were residents of an ABCs catchment site, and had a positive GBS culture from a normally sterile body site. MAIN OUTCOMES AND MEASURES Trends in GBS cases overall and by demographic characteristics (sex, age, and race), underlying clinical conditions of patients, and isolate characteristics are described. RESULTS The ABCs network detected 21 250 patients with invasive GBS among nonpregnant adults from 2008 through 2016. The GBS incidence in this population increased from 8.1 cases per 100 000 population in 2008 to 10.9 in 2016 (P = .002 for trend). There were 3146 cases reported in 2016 (59% male; median age, 64 years; age range, 18-103 years). The GBS incidence was higher among men than women and among blacks than whites and increased with age. Projected to the US population, an estimated 27 729 cases of invasive disease and 1541 deaths occurred in the United States in 2016. Ninety-five percent of cases in 2016 occurred in someone with at least 1 underlying condition, most commonly obesity (53.9%) and diabetes (53.4%). Resistance to clindamycin increased from 37.0% of isolates in 2011 to 43.2% in 2016 (P = .02). Serotypes Ia, Ib, II, III, and V accounted for 86.4% of isolates in 2016; serotype IV increased from 4.7% in 2008 to 11.3% in 2016 (P < .001 for trend). CONCLUSIONS AND RELEVANCE The public health burden of invasive GBS disease among nonpregnant adults is substantial and continues to increase. Chronic diseases, such as obesity and diabetes, may contribute.

Group B streptococcal endocarditis following elective surgical abortion

“…In recent population-based surveillance for invasive group B streptococcal infection from the US, about 40%-80% of group B Streptococcus isolates showed resistance to erythromycin. 2 Our patient's isolate was found to be resistant to both erythromycin and clindamycin.…”

“…1 Population-based surveillance in the United States from 2008 to 2016 documented an increase in the incidence of invasive group B streptococcal disease among nonpregnant adults from 8.1 cases/100 000 population to 10.9 cases/100 000 population. 2 Obesity and diabetes mellitus were the most frequent underlying conditions associated with the infection, and skin and soft-tissue infections and primary bacteremia were the most common disease presentations. 2 Group B streptococcal endocarditis accounted for about 2.1% of all cases of invasive disease.…”

“…2 Obesity and diabetes mellitus were the most frequent underlying conditions associated with the infection, and skin and soft-tissue infections and primary bacteremia were the most common disease presentations. 2 Group B streptococcal endocarditis accounted for about 2.1% of all cases of invasive disease. 2…”

“…Most available research on group B streptococcal endocarditis is limited to case reports and case series. 2,[5][6][7][8][9] Crespo and colleagues 5 reviewed 11 obstetrical-and gynecological-related cases of group B streptococcal endocarditis from 1985 to 2003. The majority of women (64%) had no predisposing valvular lesions, and 5 cases (45%) followed therapeutic abortion.…”

“…The majority of women (64%) had no predisposing valvular lesions, and 5 cases (45%) followed therapeutic abortion. The remaining cases related to premature rupture of the membranes (1), normal vaginal delivery (1), Papanicolaou smear (1), an infected uterine fibroid (1) and genital infection not otherwise specified (2). Six cases (54%) involved the tricuspid valve.…”