Epidemiology of nasopharyngeal colonization by S. pneumoniae in Indian infants in the first 2 years of life

Int J Pediatr Otorhinolaryngol. 2014 Oct;78(10):1701-6. doi: 10.1016/j.ijporl.2014.07.024. Epub 2014 Jul 25.

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.

Keywords: Birth cohort; Nasopharyngeal colonization; S. pneumoniae.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Drug Resistance, Bacterial
  • Female
  • Humans
  • India / epidemiology
  • Infant
  • Male
  • Nasopharynx / microbiology*
  • Pneumococcal Infections / drug therapy
  • Pneumococcal Infections / epidemiology*
  • Pneumococcal Infections / prevention & control
  • Pneumococcal Vaccines / immunology*
  • Respiratory Tract Infections / drug therapy
  • Respiratory Tract Infections / epidemiology*
  • Respiratory Tract Infections / prevention & control
  • Serogroup
  • Streptococcus pneumoniae / drug effects
  • Streptococcus pneumoniae / immunology
  • Streptococcus pneumoniae / isolation & purification*

Substances

  • 13-valent pneumococcal vaccine
  • Pneumococcal Vaccines