Program Schedule

The Impact of Obesity and Diabetes on the Risk and Outcomes of Invasive Group A Streptococcus Infections in Adults, Active Bacterial Core Surveillance (2010-2012)

Session: Poster Abstract Session: Bacteremia: Streptococcal Bacteremia
Friday, October 10, 2014
Room: The Pennsylvania Convention Center: IDExpo Hall BC
  • Langley_GAS and Obesity_Diabetes Poster_FINAL.pdf (338.9 kB)
  • Background: With limited prevention strategies, identifying prognostic factors for invasive group A Streptococcus (iGAS) infections is important.  Obesity and diabetes have been linked to increased risk of skin and soft tissue infections (SSTIs)--common manifestations of iGAS.  We analyzed iGAS incidence and outcomes in obese versus normal weight persons and diabetics versus non-diabetics. 

    Methods: We identified 2010-2012 community-onset cases of iGAS among non-pregnant adults from select counties at 10 US Active Bacterial Core surveillance sites.  Cases are defined by isolation of GAS from a normally sterile site or from a wound in a patient with necrotizing fasciitis or streptococcal toxic shock syndrome in a resident of the surveillance area.  Patient demographics, height, weight and clinical data were obtained from medical records.  We used height and weight to calculate body mass index (BMI) or imputed BMI for missing values, categorizing patients into normal weight (BMI 18.5-<25.0), overweight (25.0-<30.0), obese grades 1-2 (30.0-<40.0) and obese grade 3 (≥40.0). Through Poisson regression, we estimated iGAS incidence by BMI category and diabetes status after controlling for sex, age, race and other underlying conditions using ABCs catchment area population estimates from the 2011 Behavioral Risk Factor Surveillance System survey for denominators.  Multivariable logistic regression was used to compare risk of death by BMI category and diabetes status.

    Results: There were 2135 iGAS cases. Diabetes [relative risk (RR)= 3.0, 95% confidence interval (CI)= (2.3-3.9)] and grade 3 obesity among non-diabetics (RR= 2.8, 95%CI= 2.3-3.4) were associated with an increased risk of iGAS.  Neither obesity nor diabetes was associated with increased risk of death.  SSTIs, with the lowest case fatality ratio (1.9%) among all infection types, were more common in obese and diabetic persons compared to normal weight (p<0.001) and non-diabetic (p=0.001) persons, respectively.

    Conclusion: Diabetes and extreme obesity in non-diabetics were independent risk factors for iGAS. SSTIs, which tend to be less severe than other infection types, seem to be driving the increased risk.  Efforts to prevent and treat obesity and diabetes may help reduce the occurrence of iGAS.

    Gayle E. Langley, MD, MPH1, Tracy Pondo, MSPH1, Lee Harrison, MD2, Monica M. Farley, MD3, Mary Lou Lindegren, MD, MPH4, Megin Nichols, DVM, MPH, DACVPM5, Ann Thomas, MD, MPH6, Kathryn Como-Sabetti, MPH7, Susan Petit, MPH8, Mirasol M. Apostol, MPH9, Nong Shang, PhD10 and Chris Van Beneden, MD, MPH1, (1)Respiratory Diseases Branch, Centers for Disease Control and Prevention, Atlanta, GA, (2)Infectious Diseases, University of Pittsburgh, Pittsburgh, PA, (3)Emory University School of Medicine, Atlanta, GA, (4)Vanderbilt University School of Medicine, Nashville, TN, (5)New Mexico Department of Public Health, Santa Fe, NM, (6)Oregon Public Health Division, Portland, OR, (7)Minnesota Department of Health, St. Paul, MN, (8)Connecticut Emerging Infections Program, New Haven, CT, (9)California Emerging Infections Program, Oakland, CA, (10)CDC, Atlanta, GA


    G. E. Langley, None

    T. Pondo, None

    L. Harrison, None

    M. M. Farley, None

    M. L. Lindegren, None

    M. Nichols, None

    A. Thomas, None

    K. Como-Sabetti, None

    S. Petit, None

    M. M. Apostol, None

    N. Shang, None

    C. Van Beneden, None

    Findings in the abstracts are embargoed until 12:01 a.m. EDT, Oct. 8th with the exception of research findings presented at the IDWeek press conferences.

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