title: Estimating the burden of invasive Group B Streptococcal disease in young infants in southern mainland China: an observational study.
abstract: OBJECTIVE
  To estimate the incidence, case fatality ratio and serotypes associated with early-onset (EOD) and late-onset (LOD) invasive GBS disease in infants in southern mainland China.
  
  
  METHODS
  During the six-month study period, infants aged ≤ 90 days with culture-confirmed GBS disease born in the study hospitals or elsewhere, but presenting to a study hospital, were enrolled. GBS-positive cultures were genotyped, serotyped and sequence typed. The incidence rate was calculated for infants born in the study hospitals, and case fatality ratio and causative serotypes identified for all enrolled GBS cases.
  
  
  RESULTS
  Ten cases were enrolled: 2 EOD cases born in the study hospitals and 8 LOD cases born elsewhere. Incidence rate was 0.28 (95% confidence interval: 0.08-1.03, n = 2/7061 successfully followed-up consenting subjects); no cases resulted in fatality. In the 8 GBS isolates available for typing, 4 serotypes (Ia, Ib, III and V) and 5 multi-locus sequence types (1, 10, 12, 17 and 23) were identified.
  
  
  CONCLUSIONS
  This is the first study specifically investigating the incidence of GBS invasive disease in infants in southern mainland China. Incidence and case fatality were low but further research is needed in larger, more diverse cohorts to estimate disease burden for the broader Chinese population.
authors.affiliation: Guangzhou Women and Children's Medical Center, Guangzhou Medical University Guangzhou, China.
authors.forename: Haiying
authors.initials: H
authors.lastname: Liu
authors.affiliation: Changsha Hospital for Maternal and Child Health Changsha, China.
authors.forename: Houlin
authors.initials: H
authors.lastname: Zeng
authors.affiliation: Changsha Hospital for Maternal and Child Health Changsha, China.
authors.forename: Weidong
authors.initials: W
authors.lastname: Wang
authors.affiliation: Guangzhou Women and Children's Medical Center, Guangzhou Medical University Guangzhou, China.
authors.forename: Qiulan
authors.initials: Q
authors.lastname: Deng
authors.affiliation: Novartis Vaccines and Diagnostics Srl Siena, Italy - A GSK Company.
authors.forename: Immaculada
authors.initials: I
authors.lastname: Margarit
authors.affiliation: Novartis Vaccines and Diagnostics Srl Siena, Italy - A GSK Company.
authors.forename: C Daniela
authors.initials: CD
authors.lastname: Rinaudo
authors.affiliation: GlaxoSmithKline B.V. Amsterdam, Netherlands.
authors.forename: Todd
authors.initials: T
authors.lastname: Swarthout
authors.affiliation: GlaxoSmithKline Plc United Kingdom.
authors.forename: Marianne
authors.initials: M
authors.lastname: Cunnington
authors.affiliation: GlaxoSmithKline (China) Investment Co Ltd Shanghai, China.
authors.forename: Wenjing
authors.initials: W
authors.lastname: Ji
authors.affiliation: GlaxoSmithKline (China) Investment Co Ltd Shanghai, China.
authors.forename: Guozhu
authors.initials: G
authors.lastname: Geng
keywords: China; Group B Streptococcus; case fatality; incidence; infants; serotype