title: The challenge of ongoing Haemophilus influenzae type B carriage and transmission in Alaska.
abstract: Cases of invasive Haemophilus influenzae type b disease in Alaskan children quickly dropped 10-fold after widespread vaccination with a conjugate vaccine (PRP-OMP) began in 1991. However, reemergence of invasive disease in 1996-97 soon followed a change to a combination diphtheria-tetanus toxoid-pertussis/H. influenzae type b vaccine which incorporates a different conjugate vaccine (HbOC). Previously unrecognized persistence of H. influenzae type b carriage in rural Alaska, coupled with characteristics of the immune response to HbOC, are the likely explanations for disease reemergence. The current vaccine recommendation--PRP-OMP for the first dose, followed by HbOC to complete the vaccination series--appears to protect Alaskan infants even in the face of continuing carriage and transmission. Successful control of invasive H. influenzae type b disease in Alaskan children will require not only appropriate immunization, but also continuing surveillance for both disease and carriage, identification of factors associated with carriage, and investigation into the feasibility of using vaccination plus antimicrobial drugs to eliminate this pathogen.
authors.affiliation: Arctic Investigations Program, National Center for Infectious Diseases, Centers for Disease Control and Prevention, Anchorage, AK, USA.
authors.forename: L A
authors.initials: LA
authors.lastname: Lucher
authors.forename: R
authors.initials: R
authors.lastname: Singleton
authors.forename: A J
authors.initials: AJ
authors.lastname: Parkinson
authors.forename: J C
authors.initials: JC
authors.lastname: Butler
mesh_terms: D000413:Alaska / Q000453:epidemiology; D002675:Child, Preschool; D004196:Disease Outbreaks / Q000517:prevention & control*; D006192:Haemophilus Infections / Q000453:epidemiology / Q000517:prevention & control* / Q000635:transmission*; D019741:Haemophilus influenzae type b; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D011159:Population Surveillance; D017778:Vaccines, Combined / Q000627:therapeutic use; D014765:Viral Vaccines / Q000627:therapeutic use
chemical_list: D017778:Vaccines, Combined; D014765:Viral Vaccines