Risk factors for primary invasive Haemophilus influenzae disease: increased risk from day care attendance and school-aged household members

J Pediatr. 1985 Feb;106(2):190-5. doi: 10.1016/s0022-3476(85)80285-7.


From November 1, 1981, through April 30, 1982, we performed a case-control study of primary invasive Haemophilus influenzae infections in children in Colorado. Information was collected for 121 (83%) of 146 children with positive cultures and for 196 (67%) of 292 age-matched controls selected at random from birth certificates. Infected children were more likely to have attended a day care center or nursery (DCC/N) and to have an elementary school-aged household member. For attendance at DCC/N, the relative risk was significantly increased only for children 12 months of age or older, and increased with the size of the DCC/N. After controlling for DCC/N attendance and school-aged siblings, children younger than 6 months of age with infection were significantly less likely to have been breast-fed, suggesting a protective effect of breast-feeding. We identified DCC/N attendees, especially those older than 1 year of age, to be at increased risk of primary H. influenzae disease. They could benefit from immunization.

MeSH terms

  • Breast Feeding
  • Child
  • Child Day Care Centers*
  • Child, Preschool
  • Colorado
  • Cross Infection / epidemiology
  • Cross Infection / transmission
  • Family
  • Haemophilus Infections / epidemiology
  • Haemophilus Infections / transmission*
  • Haemophilus influenzae / isolation & purification
  • Humans
  • Infant
  • Infant, Newborn
  • Risk
  • Schools
  • Schools, Nursery*
  • Surveys and Questionnaires