title: Epidemiology of invasive pneumococcal disease in the pre-conjugate vaccine era: South Africa, 2003-2008.
abstract: BACKGROUND
  Dynamics of pneumococcal disease incidence and serotype distribution prior to introduction of pneumococcal conjugate vaccines (PCV) will assist in understanding effects of the vaccine over time and will be important in choosing the optimal PCV formulation.
  
  
  METHODS
  We conducted active, laboratory-based, national surveillance for invasive pneumococcal disease (IPD) through the Group for Enteric, Respiratory and Meningeal Disease Surveillance in South Africa (GERMS-SA) from 2003 through 2008. Over 130 laboratories report to this system. Pneumococci were serotyped using Quellung and isolates screened for resistance by disk diffusion; minimum inhibitory concentrations were determined on potentially resistant isolates. We used univariate and multivariable multinomial regression models to assess differences between serotypes.
  
  
  RESULTS
  GERMS-SA identified 8674 cases among children <5 years. Overall, 58% (3849/6668), 65% (4314/6668), and 85% (5669/6668) of cases and 61% (455/751), 64% (482/751), 82% (616/751) of deaths were due to serotypes included in 7-valent PCV, 10-valent PCV and 13-valent PCV, respectively. Serotypes 6A and 19A accounted for 16% (527/3252) of penicillin non-susceptible disease. In 2008, reported incidence of IPD was 6-fold higher in children <1 compared to children 1-4 years of age: 87 per 100,000 population and 14/100,000, respectively. The relative risk of IPD was 21-fold (95% CI, 19-24) and 34-fold (29-41) greater in HIV-infected compared to HIV-uninfected children in the <1 year and 1-4-year-old age groups respectively. On multivariable analysis serotypes 6B (relative risk ratio (RRR) 0.7; confidence interval (CI) 0.5-0.9), 18C (RRR 0.3; CI 0.1-0.5), 1 (RRR 0.2; CI 0.1-0.4) and 8 (RRR 0.2; CI 0.1-0.4) were significantly less common in HIV-infected individuals than serotype 14.
  
  
  CONCLUSIONS
  All vaccine formulations have the potential to prevent most cases and deaths from IPD in children in South Africa. Vaccines with protection against 19A would be advantageous in South Africa.
authors.affiliation: National Institute for Communicable Diseases (NICD) of the National Health Laboratory Service (NHLS), Johannesburg, South Africa. annev@nicd.ac.za
authors.forename: Anne
authors.initials: A
authors.lastname: von Gottberg
authors.forename: Cheryl
authors.initials: C
authors.lastname: Cohen
authors.forename: Linda
authors.initials: L
authors.lastname: de Gouveia
authors.forename: Susan
authors.initials: S
authors.lastname: Meiring
authors.forename: Vanessa
authors.initials: V
authors.lastname: Quan
authors.forename: Andrew
authors.initials: A
authors.lastname: Whitelaw
authors.forename: Penny
authors.initials: P
authors.lastname: Crowther-Gibson
authors.forename: Shabir A
authors.initials: SA
authors.lastname: Madhi
authors.forename: Cynthia G
authors.initials: CG
authors.lastname: Whitney
authors.forename: Keith P
authors.initials: KP
authors.lastname: Klugman
mesh_terms: D002675:Child, Preschool; D015658:HIV Infections / Q000382:microbiology; D006801:Humans; D007223:Infant; D015999:Multivariate Analysis; D011008:Pneumococcal Infections / Q000453:epidemiology* / Q000382:microbiology / Q000517:prevention & control*; D022242:Pneumococcal Vaccines / Q000627:therapeutic use*; D013019:South Africa / Q000453:epidemiology; D013296:Streptococcus pneumoniae / Q000302:isolation & purification; D018074:Vaccines, Conjugate / Q000627:therapeutic use*
chemical_list: D022242:Pneumococcal Vaccines; D018074:Vaccines, Conjugate
keywords: Laboratory-based surveillance; Pneumococcal disease; Pneumococcus; South Africa; Streptococcus pneumoniae; Vaccine-preventable disease