title: Acquisition of Streptococcus pneumoniae in pneumococcal conjugate vaccine-naïve South African children and their mothers.
abstract: BACKGROUND
  Pneumococcal nasopharyngeal colonization is a prerequisite to developing pneumococcal disease. We investigated the dynamics of pneumococcal colonization in perinatal HIV-unexposed and HIV-exposed children and their mothers and risk factors associated with new serotypes acquisition.
  
  
  METHODS
  Two hundred forty-three mother-child pairs (120 HIV-infected, 123 HIV-uninfected mothers) were studied at 4.4, 7.2, 9.4, 12.3 and 16.0 months of the child's age. Demographic data, nasopharyngeal swabs, as well as oropharyngeal swabs, from mothers were collected for pneumococcal conventional culture and serotyping by the Quellung method.
  
  
  RESULTS
  The rate of new serotype acquisition during the 16 months did not differ between HIV-exposed (49.1%) and HIV-unexposed (52.0%) children, or between HIV-infected (18.9%) and HIV-uninfected (19.5%) mothers. Serotypes included in the 7-valent pneumococcal conjugate vaccine (PCV7) were acquired more often by HIV-infected (10.0%) compared with HIV-uninfected mothers (6.4%; P = 0.03). On multivariate analysis, day-care attendance (adjusted odds ratio [AOR], = 1.80, P = 0.02) and maternal pneumococcal colonization (AOR = 1.54, P = 0.01) were positively associated with pneumococcal acquisition in the child, whereas breast-feeding had a protective effect on PCV7-serotype acquisition in HIV-uninfected children. New acquisition of PCV7 and PCV13 serotypes in the mother was positively associated with colonization in the child (AOR = 2.01, P = 0.006 and AOR = 2.04, P = 0.002, respectively).
  
  
  CONCLUSIONS
  There is an association of acquisition of PCV7 and PCV13 serotypes between young children and their mothers. The higher prevalence of PCV7 serotype in HIV-infected mothers suggests that they may be a reservoir for transmission of these serotypes, which could delay indirect effects of PCV in settings with a high HIV burden.
authors: Department of Science and Technology/National Research Foundation: Vaccine Preventable Diseases, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa.
authors: Marta C
authors: MC
authors: Nunes
authors: Tinevimbo
authors: T
authors: Shiri
authors: Nadia
authors: N
authors: van Niekerk
authors: Clare L
authors: CL
authors: Cutland
authors: Michelle J
authors: MJ
authors: Groome
authors: Anthonet
authors: A
authors: Koen
authors: Anne
authors: A
authors: von Gottberg
authors: Linda
authors: L
authors: de Gouveia
authors: Keith P
authors: KP
authors: Klugman
authors: Peter V
authors: PV
authors: Adrian
authors: Shabir A
authors: SA
authors: Madhi
mesh_terms: D002353:Carrier State / Q000453:epidemiology / Q000382:microbiology* / Q000635:transmission / Q000821:virology; D016009:Chi-Square Distribution; D002656:Child Day Care Centers; D005191:Family Characteristics; D005260:Female; D015658:HIV Infections / Q000453:epidemiology / Q000382:microbiology* / Q000821:virology; D006801:Humans; D007223:Infant; D009305:Nasopharynx / Q000382:microbiology; D011008:Pneumococcal Infections / Q000453:epidemiology / Q000382:microbiology* / Q000635:transmission / Q000821:virology; D011446:Prospective Studies; D012307:Risk Factors; D013019:South Africa / Q000453:epidemiology; D013296:Streptococcus pneumoniae / Q000254:growth & development / Q000302:isolation & purification / Q000472:pathogenicity*