Group B streptococci (GBS) infection can be rapidly fatal. In early-onset infection, even with prompt and appropriate treatment, mortality is 4% to 13%.[21]Schuchat A. Epidemiology of group B streptococcal disease in the United States: shifting paradigms. Clin Microbiol Rev. 1998 Jul;11(3):497-513.
http://cmr.asm.org/cgi/content/full/11/3/497
http://www.ncbi.nlm.nih.gov/pubmed/9665980?tool=bestpractice.com
[71]Yagupsky P, Menegus MA, Powell KR. The changing spectrum of group B streptococcal disease in infants: an eleven-year experience in a tertiary care hospital. Pediatr Infect Dis J. 1991 Nov;10(11):801-8.
http://www.ncbi.nlm.nih.gov/pubmed/1749691?tool=bestpractice.com
Mortality is higher in lower-weight babies (42% case fatality rate in babies <2500 g versus 7% in babies ≥2500 g).[28]Zaleznik DF, Rench MA, Hillier S, et al. Invasive disease due to group B streptococcus in pregnant women and neonates from diverse population groups. Clin Infect Dis. 2000 Feb;30(2):276-81.
http://www.ncbi.nlm.nih.gov/pubmed/10671328?tool=bestpractice.com
In late-onset infection, mortality is highest in those who present with meningitis. Overall case fatality is low, at 3%.[17]Schuchat A, Oxtoby M, Sikes S, et al. Population-based risk factors for neonatal group B streptococcal disease: results of a cohort study in metropolitan Atlanta. J Infect Dis. 1990 Sep;162(3):672-7.
http://www.ncbi.nlm.nih.gov/pubmed/2201741?tool=bestpractice.com
[71]Yagupsky P, Menegus MA, Powell KR. The changing spectrum of group B streptococcal disease in infants: an eleven-year experience in a tertiary care hospital. Pediatr Infect Dis J. 1991 Nov;10(11):801-8.
http://www.ncbi.nlm.nih.gov/pubmed/1749691?tool=bestpractice.com
GBS infection is more likely to be fatal in adults than in children. Mortality depends on the focus of infection, with pneumonia having a mortality of 41%. Overall mortality is 21% to 25%.[21]Schuchat A. Epidemiology of group B streptococcal disease in the United States: shifting paradigms. Clin Microbiol Rev. 1998 Jul;11(3):497-513.
http://cmr.asm.org/cgi/content/full/11/3/497
http://www.ncbi.nlm.nih.gov/pubmed/9665980?tool=bestpractice.com
[26]Carstensen H, Christensen KK, Grennert L, et al. Early-onset neonatal group b streptococcal septicaemia in siblings. J Infect. 1988 Nov;17(3):201-4.
http://www.ncbi.nlm.nih.gov/pubmed/3063756?tool=bestpractice.com
Infective endocarditis from GBS can affect native and prosthetic valves and is associated with high mortality.[100]Sambola A, Miro JM, Tornos MP, et al. Streptococcus agalactiae infective endocarditis: analysis of 30 cases and review of the literature. Clin Infect Dis. 2002 Jun 15;34(12):1576-84.
http://www.ncbi.nlm.nih.gov/pubmed/12032892?tool=bestpractice.com
Monitoring
Standard monitoring of patients on treatment should take place. This normally consists of repeat complete blood count, C-reactive protein, and BUN and electrolytes at regular intervals until resolution. Follow-up cultures are not generally recommended but may be appropriate in patients who are not responding to therapy. Likewise, follow-up imaging may be required in certain circumstances.
Morbidity
Of nonpregnant adults who survive a GBS invasive infection, 4% will have a recurrence.[101]Harrison LH, Ali A, Dwyer DM, et al. Relapsing invasive group B streptococcal Infection in adults. Ann Intern Med. 1995 Sep 15;123(6):421-7.
http://www.ncbi.nlm.nih.gov/pubmed/7639441?tool=bestpractice.com
GBS arthritis can result in permanent functional impairment of the affected joint. GBS disease in childhood is associated with an increased risk of neurodevelopmental impairment. The risk is particularly high with GBS meningitis.[102]Kohli-Lynch M, Russell NJ, Seale AC, et al. Neurodevelopmental impairment in children after group B streptococcal disease worldwide: systematic review and meta-analyses. Clin Infect Dis. 2017 Nov 6;65(suppl_2):S190-S9.
https://academic.oup.com/cid/article/65/suppl_2/S190/4589593
http://www.ncbi.nlm.nih.gov/pubmed/29117331?tool=bestpractice.com
[103]Horváth-Puhó E, van Kassel MN, Gonçalves BP, et al. Mortality, neurodevelopmental impairments, and economic outcomes after invasive group B streptococcal disease in early infancy in Denmark and the Netherlands: a national matched cohort study. Lancet Child Adolesc Health. 2021 Jun;5(6):398-407.
https://www.sciencedirect.com/science/article/pii/S2352464221000225?via%3Dihub
http://www.ncbi.nlm.nih.gov/pubmed/33894156?tool=bestpractice.com