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. 2024 Oct;52(5):1745-1752.
doi: 10.1007/s15010-024-02210-3. Epub 2024 Mar 14.

Incidence of invasive infections with Group B streptococcus in adults in Norway 1996-2019: a nationwide registry-based case-control study

Elise Uggen  1   2 , Camilla Olaisen  3 , Randi Valsø Lyng  3 , Gunnar Skov Simonsen  4   5 , Roar Magne Bævre-Jensen  6 , Frode Width Gran  3 , Bjørn Olav Åsvold  7   8   9 , Tom Ivar Lund Nilsen  10   11 , Jan Kristian Damås  12   13   14 , Jan Egil Afset  12   3   13
Affiliations

Incidence of invasive infections with Group B streptococcus in adults in Norway 1996-2019: a nationwide registry-based case-control study

Elise Uggen et al. Infection. 2024 Oct.

Abstract

Purpose: Group B streptococcus (GBS) colonizes the gastrointestinal and vaginal mucosa in healthy adults, but has also become an increasing cause of invasive infection. The aims of this study were to describe the incidence and factors associated with the occurrence of invasive GBS disease in adults in Norway.

Methods: We performed a nationwide retrospective case-control study of invasive GBS infections during 1996-2019, with two control groups; invasive Group A streptococcal disease (GAS) to control for changes in surveillance and diagnostics, and a second representing the general population.

Results: A total of 3710 GBS episodes were identified. The age-standardized incidence rate increased steadily from 1.10 (95% CI 0.80-1.50) in 1996 to 6.70 (95% CI 5.90-7.50) per 100,000 person-years in 2019. The incidence rate had an average annual increase of 6.44% (95% CI 5.12-7.78). Incidence rates of GAS varied considerably, and there was no evidence of a consistent change over the study period. GBS incidence was highest among adults > 60 years of age. Cardiovascular disease, cancer, and diabetes were the most common comorbid conditions. There was a shift in the distribution of capsular serotypes from three dominant types to more equal distribution among the six most common serotypes.

Conclusions: The incidence of invasive GBS disease in adults increased significantly from 1996 to 2019. The increasing age of the population with accompanying underlying comorbid conditions might contribute to the increasing burden of invasive GBS disease. Interestingly, type 1 diabetes was also associated with the occurrence of invasive GBS disease.

Keywords: Streptococcus agalactiae; GBS; Group B streptococcus; Incidence; Invasive disease; Risk factors.

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Conflict of interest statement

None.

Figures

Fig. 1
Fig. 1
Age standardized incidence rates of A invasive group B streptococcal disease and B invasive group A streptococcal disease per 100,000 with 95% CI
Fig. 2
Fig. 2
Incidence of invasive group B streptococcal disease in adults 1996–2019 by age group presented as incidence rate (A) and number of infection episodes (B)
Fig. 3
Fig. 3
Proportion of A capsular serotypes and B surface protein genes, with 95% confidence intervals, 5-year periods *last time period only four years
See this image and copyright information in PMC

References

    1. Hood M, Janney A, Dameron G. Beta hemolytic streptococcus Group B associated with problems of the perinatal period. Am J Obstet Gynecol. 1961;82:809–18. 10.1016/S0002-9378(16)36146-4. - PubMed
    1. Ali MM, Asrat D. Variation of invasive neonatal GBS disease across the regions. Lancet Glob Health. 2022;10:e776–7. 10.1016/S2214-109X(22)00182-6. - PubMed
    1. Ballard MS, Schønheyder HC, Knudsen JD, Lyytikäinen O, Dryden M, Kennedy KJ, et al. The changing epidemiology of group B streptococcus bloodstream infection: a multi-national population-based assessment. Infect Dis. 2016;48:386–91. 10.3109/23744235.2015.1131330. - PubMed
    1. Francois Watkins LK, McGee L, Schrag SJ, Beall B, Jain JH, Pondo T, et al. Epidemiology of invasive group B streptococcal infections among nonpregnant adults in the United States, 2008–2016. JAMA Intern Med. 2019;179:479. 10.1001/jamainternmed.2018.7269. - PMC - PubMed
    1. Skoff TH, Farley MM, Petit S, Craig AS, Schaffner W, Gershman K, et al. Increasing burden of invasive Group B Streptococcal disease in nonpregnant adults, 1990–2007. Clin Infect Dis. 2009;49:85–92. 10.1001/jamainternmed.2018.7269. - PubMed

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