title: Epidemiology of nasopharyngeal colonization by S. pneumoniae in Indian infants in the first 2 years of life.
abstract: BACKGROUND
  Streptococcus pneumoniae is a leading cause of invasive disease in developing countries like India. Although the 13 valent pneumococcal vaccine has already been introduced in the country, there is very little epidemiological data regarding S. pneumoniae colonization and antibiotic susceptibility in Indian infants.
  
  
  METHODS
  We studied serogroup/serotype (SGT) distribution and antibiotic susceptibility pattern of S. pneumoniae in unvaccinated Indian infants by performing monthly nasopharyngeal swabbing of a birth cohort for 2 years.
  
  
  RESULTS
  Colonization began soon after birth and was complete in the first year of life in the majority of those colonized. Carriage rates increased during winter (p<0.01) and in those with upper respiratory infection (URI) (p<0.01). The most frequently (76.1%) isolated SGT were 19, 6, 15, 23, 9, 35 and 10. Vaccine SGT accounted for 60.5% of all colonizers. Antibiotic resistance was maximum for cotrimoxazole (94.3%) and least for erythromycin (11.2%) with no penicillin resistance. Ten of the commonest SGT which cause invasive disease among Indian infants comprised 46.9% of the colonizers. Serogroups 1, 5, 45 and 12 which cause invasive disease in under-fives were not seen in this birth cohort in the first year.
  
  
  CONCLUSIONS
  S. pneumoniae colonization in Indian infants commences soon after birth and chiefly occurs in the first year of life. The 13 valent vaccine may protect against a little less than half the commonly seen invasive SGT of S. pneumoniae.
authors.affiliation: Department of ENT, Christian Medical College, Vellore, India. Electronic address: rupavedantam@cmcvellore.ac.in.
authors.forename: Vedantam
authors.initials: V
authors.lastname: Rupa
authors.affiliation: Department of RUHSA, Christian Medical College, Vellore, India.
authors.forename: Rita
authors.initials: R
authors.lastname: Isaac
authors.affiliation: Department of Medicine (Infectious Diseases Unit), Christian Medical College, Vellore, India.
authors.forename: Ranganathan
authors.initials: R
authors.lastname: Jalagandeeswaran
authors.affiliation: Department of Medicine (Infectious Diseases Unit), Christian Medical College, Vellore, India.
authors.forename: Anand
authors.initials: A
authors.lastname: Manoharan
authors.affiliation: Department of Biostatistics, Christian Medical College, Vellore, India.
authors.forename: Grace
authors.initials: G
authors.lastname: Rebekah
mesh_terms: D024881:Drug Resistance, Bacterial; D005260:Female; D006801:Humans; D007194:India / Q000453:epidemiology; D007223:Infant; D008297:Male; D009305:Nasopharynx / Q000382:microbiology*; D011008:Pneumococcal Infections / Q000188:drug therapy / Q000453:epidemiology* / Q000517:prevention & control; D022242:Pneumococcal Vaccines / Q000276:immunology*; D012141:Respiratory Tract Infections / Q000188:drug therapy / Q000453:epidemiology* / Q000517:prevention & control; D065288:Serogroup; D013296:Streptococcus pneumoniae / Q000187:drug effects / Q000276:immunology / Q000302:isolation & purification*
chemical_list: C538862:13-valent pneumococcal vaccine; D022242:Pneumococcal Vaccines
keywords: Birth cohort; Nasopharyngeal colonization; S. pneumoniae