title: Temporal association of infant immunisation with pneumococcal conjugate vaccine on the ecology of Streptococcus pneumoniae, Haemophilus influenzae and Staphylococcus aureus nasopharyngeal colonisation in a rural South African community.
abstract: BACKGROUND
  Immunisation of children with pneumococcal conjugate vaccines (PCV) may affect the bacterial-ecology of the nasopharynx, including colonisation by Streptococcus pneumoniae, Haemophilus influenzae and Staphylococcus aureus. The aim of this study was to evaluate the effect of infant PCV-immunisation on the nasopharyngeal ecology of these potentially pathogenic bacteria in a rural African setting.
  
  
  METHODS
  Two cross sectional surveys were undertaken from May to October in 2009 (Period-1) which coincided with the introduction of 7-valent PCV (PCV7) and in May-October 2011 (Period-2). Consenting household members, where there was a child <2 years of age in residence, had nasopharyngeal swabs undertaken for culture.
  
  
  RESULTS
  From Period-1 to Period-2 in children 0-2 years and 3-12 years, prevalence of overall S. pneumoniae colonisation decreased from 74.9% to 67.0% (p<0.001) and H. influenzae declined among children 3-12 years (55.1-45.3%, p<0.001) but not among those <2 years. The prevalence of S. aureus remained unchanged in all children. Competitive associations were found between S. pneumoniae and S. aureus and between H. influenzae and S. aureus among children. In individuals >12 years, the prevalence of colonisation decreased from 11.2% to 6.8%, 16.7% to 8.8% and 31.2% to 23.7% for S. pneumoniae, H. influenzae and S. aureus, respectively; p<0.001 for all comparions. Synergistic relationships for S. aureus with H. influenzae and S. pneumoniae were observed in both periods among this group.
authors.affiliation: Department of Science and Technology/National Research Foundation: Vaccine Preventable Diseases, University of the Witwatersrand, Johannesburg, South Africa; Medical Research Council: Respiratory and Meningeal Pathogens Research Unit, University of the Witwatersrand, Johannesburg, South Africa.
authors.forename: S A
authors.initials: SA
authors.lastname: Nzenze
authors.affiliation: Department of Science and Technology/National Research Foundation: Vaccine Preventable Diseases, University of the Witwatersrand, Johannesburg, South Africa; Medical Research Council: Respiratory and Meningeal Pathogens Research Unit, University of the Witwatersrand, Johannesburg, South Africa.
authors.forename: T
authors.initials: T
authors.lastname: Shiri
authors.affiliation: Department of Science and Technology/National Research Foundation: Vaccine Preventable Diseases, University of the Witwatersrand, Johannesburg, South Africa; Medical Research Council: Respiratory and Meningeal Pathogens Research Unit, University of the Witwatersrand, Johannesburg, South Africa.
authors.forename: M C
authors.initials: MC
authors.lastname: Nunes
authors.affiliation: Medical Research Council: Respiratory and Meningeal Pathogens Research Unit, University of the Witwatersrand, Johannesburg, South Africa; Department of Global Health, Rollins School of Public Health, Division of Infectious Diseases, School of Medicine, Emory University, Atlanta, GA, USA.
authors.forename: K P
authors.initials: KP
authors.lastname: Klugman
authors.affiliation: MRC/Wits Rural Public Health and Health Transitions Research Unit (Agincourt), School of Public Health, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa; Centre for Global Health Research, Umeå University, Umeå, Sweden; INDEPTH Network, Accra, Ghana.
authors.forename: K
authors.initials: K
authors.lastname: Kahn
authors.affiliation: MRC/Wits Rural Public Health and Health Transitions Research Unit (Agincourt), School of Public Health, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa.
authors.forename: R
authors.initials: R
authors.lastname: Twine
authors.affiliation: Medical Research Council: Respiratory and Meningeal Pathogens Research Unit, University of the Witwatersrand, Johannesburg, South Africa; National Institute for Communicable Diseases (NICD): A Division of the National Health Laboratory Service (NHLS), Sandringham, South Africa.
authors.forename: L
authors.initials: L
authors.lastname: de Gouveia
authors.affiliation: Medical Research Council: Respiratory and Meningeal Pathogens Research Unit, University of the Witwatersrand, Johannesburg, South Africa; National Institute for Communicable Diseases (NICD): A Division of the National Health Laboratory Service (NHLS), Sandringham, South Africa.
authors.forename: A
authors.initials: A
authors.lastname: von Gottberg
authors.affiliation: Department of Science and Technology/National Research Foundation: Vaccine Preventable Diseases, University of the Witwatersrand, Johannesburg, South Africa; Medical Research Council: Respiratory and Meningeal Pathogens Research Unit, University of the Witwatersrand, Johannesburg, South Africa; National Institute for Communicable Diseases (NICD): A Division of the National Health Laboratory Service (NHLS), Sandringham, South Africa. Electronic address: shabirm@nicd.ac.za.
authors.forename: S A
authors.initials: SA
authors.lastname: Madhi
mesh_terms: D000293:Adolescent; D000328:Adult; D002353:Carrier State / Q000453:epidemiology*; D002648:Child; D002675:Child, Preschool; D003430:Cross-Sectional Studies; D005260:Female; D006193:Haemophilus influenzae / Q000302:isolation & purification*; D000069443:Heptavalent Pneumococcal Conjugate Vaccine; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D008875:Middle Aged; D009305:Nasopharynx / Q000382:microbiology; D011008:Pneumococcal Infections / Q000517:prevention & control; D022242:Pneumococcal Vaccines / Q000627:therapeutic use*; D012424:Rural Population; D013019:South Africa / Q000453:epidemiology; D013211:Staphylococcus aureus / Q000302:isolation & purification*; D013296:Streptococcus pneumoniae / Q000302:isolation & purification*; D013997:Time Factors; D018074:Vaccines, Conjugate / Q000627:therapeutic use; D055815:Young Adult
chemical_list: D000069443:Heptavalent Pneumococcal Conjugate Vaccine; D022242:Pneumococcal Vaccines; D018074:Vaccines, Conjugate
keywords: Haemophilus influenzae; Infant immunisation; Nasopharyngeal colonisation; Pneumococcal conjugate vaccine; Staphylococcus aureus; Streptococcus pneumoniae