B 族链球菌 (GBS) 感染可迅速致命。在早发型感染患者中,即使及时给予适当治疗,死亡率仍达到 4%-13%。[23]Schuchat A. Epidemiology of group B streptococcal disease in the United States: shifting paradigms. Clin Microbiol Rev. 1998;11:497-513.http://cmr.asm.org/cgi/content/full/11/3/497http://www.ncbi.nlm.nih.gov/pubmed/9665980?tool=bestpractice.com[52]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;10:801-808.http://www.ncbi.nlm.nih.gov/pubmed/1749691?tool=bestpractice.com体重较低婴儿的死亡率更高(体重低于 2500 g 婴儿的病死率是 42%,而体重大于等于 2500 g 婴儿的病死率是 7%)。[31]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;30:276-281.http://www.ncbi.nlm.nih.gov/pubmed/10671328?tool=bestpractice.com
在晚发型感染患者中,以脑膜炎患者的死亡率最高。总体病死率较低,仅有 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;162:672-677.http://www.ncbi.nlm.nih.gov/pubmed/2201741?tool=bestpractice.com[52]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;10:801-808.http://www.ncbi.nlm.nih.gov/pubmed/1749691?tool=bestpractice.com
与儿童相比,成人的B族链球菌感染更可能致命。死亡率取决于感染疾病灶,肺炎患者的死亡率达到 41%。总体病死率为 21%-25%。[27]Carstensen H, Christensen KK, Grennert L, et al. Early-onset neonatal group b streptococcal septicaemia in siblings. J Infect. 1988;17:201-204.http://www.ncbi.nlm.nih.gov/pubmed/3063756?tool=bestpractice.com[23]Schuchat A. Epidemiology of group B streptococcal disease in the United States: shifting paradigms. Clin Microbiol Rev. 1998;11:497-513.http://cmr.asm.org/cgi/content/full/11/3/497http://www.ncbi.nlm.nih.gov/pubmed/9665980?tool=bestpractice.com
B族链球菌引发的感染性心内膜炎可对自体瓣膜和人工瓣膜造成影响,并与高死亡率具有相关性。[71]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;34;1576-1584.http://www.ncbi.nlm.nih.gov/pubmed/12032892?tool=bestpractice.com
监测
应对接受治疗的患者进行标准监测。这通常包括定期反复进行全血细胞计数、C 反应蛋白、尿素和电解质检查,直至炎症消退。通常不推荐进行随访培养,但是随访培养可能适用于对治疗无反应的患者。同样地,在某些情况下,可能需要进行随访影像学检查。
并发症发病率
在经历侵袭性 B族链球菌感染而存活的非妊娠成人中,有4% 会复发。[72]Harrison LH, Ali A, Dwyer DM, et al. Relapsing invasive group B streptococcal Infection in adults. Ann Intern Med. 1995;123:421-427.http://www.ncbi.nlm.nih.gov/pubmed/7639441?tool=bestpractice.comB 族链球菌感染性脑膜炎可导致显著的神经系统后遗症(尤其在早产儿中),高达 50% 的病例会出现神经系统后遗症。[73]Wald ER, Bergman I, Taylor HG, et al. Long-term outcome of group B streptococcal meningitis. Pediatrics. 1986;7:217-221.http://www.ncbi.nlm.nih.gov/pubmed/3511445?tool=bestpractice.com耳聋是最常见的并发症。B族链球菌感染性关节炎可导致受累关节出现永久性功能缺损。