title: Impact of Haemophilus influenzae Type b conjugate vaccine in Mongolia: prospective population-based surveillance, 2002-2010.
abstract: OBJECTIVE
  Bacterial meningitis is associated with high mortality and long-term complications. This study assessed the impact of Haemophilus influenzae type b (Hib) conjugate vaccine on childhood bacterial meningitis in Ulaanbaatar, Mongolia.
  
  
  METHODS
  Prospective, active, population-based surveillance for suspected meningitis in children aged 2-59 months was conducted (February 2002-January 2011) in 6 hospitals. Clinical data, blood, and cerebrospinal fluid were collected. The impact of Hib conjugate vaccine was assessed by comparing Hib and all cause meningitis data in the 3 years preceding pentavalent conjugate vaccine implementation (2002-2004) with 3 years postimplementation (2008-2010).
  
  
  RESULTS
  Five hundred eleven cases of suspected meningitis were identified from 2002-2011. Pentavalent conjugate vaccine coverage in December 2005 in Ulaanbaatar city was 97%. The proportion of suspected cases confirmed as Hib meningitis decreased from 25% (50/201) in the prevaccination era to 2% (4/193) in the postvaccination era (P < .0001). The annual incidence of Hib decreased from 28 cases per 100,000 children in 2002-2005 to 2 per 100,000 in 2008-2010 (P < .0001).
  
  
  CONCLUSIONS
  This article demonstrates the marked impact of Hib conjugate vaccine introduction on meningitis in Mongolia. It is important to sustain this surveillance system to monitor the long-term impact of Hib conjugate vaccine, as well as other interventions such as pneumococcal and meningococcal vaccines.
authors.affiliation: Department of Infectious Disease Epidemiology, London School of Hygiene and Tropical Medicine, London, United Kingdom. susana.scott@lshtm.ac.uk
authors.forename: Susana
authors.initials: S
authors.lastname: Scott
authors.forename: Dorjpurev
authors.initials: D
authors.lastname: Altanseseg
authors.forename: Demberelsuren
authors.initials: D
authors.lastname: Sodbayer
authors.forename: Pagvajav
authors.initials: P
authors.lastname: Nymadawa
authors.forename: Davaadash
authors.initials: D
authors.lastname: Bulgan
authors.forename: Jamsran
authors.initials: J
authors.lastname: Mendsaikhan
authors.forename: James P
authors.initials: JP
authors.lastname: Watt
authors.forename: Mary P E
authors.initials: MP
authors.lastname: Slack
authors.forename: Maria G
authors.initials: MG
authors.lastname: Carvalho
authors.forename: Rana
authors.initials: R
authors.lastname: Hajjeh
authors.forename: Karen M
authors.initials: KM
authors.lastname: Edmond
mesh_terms: D016667:Bacterial Capsules / Q000276:immunology; D002675:Child, Preschool; D005260:Female; D018073:Haemophilus Vaccines / Q000008:administration & dosage* / Q000276:immunology; D019741:Haemophilus influenzae type b / Q000276:immunology*; D006801:Humans; D015994:Incidence; D007223:Infant; D008297:Male; D008583:Meningitis, Haemophilus / Q000517:prevention & control*; D008986:Mongolia / Q000453:epidemiology; D011159:Population Surveillance; D011446:Prospective Studies; D018074:Vaccines, Conjugate / Q000008:administration & dosage / Q000276:immunology
chemical_list: D018073:Haemophilus Vaccines; C044237:Haemophilus influenzae type b polysaccharide vaccine; D018074:Vaccines, Conjugate