title: Re-emergence of Haemophilus influenzae type b (Hib) disease in The Gambia following successful elimination with conjugate Hib vaccine.
abstract: Invasive Hib disease, which remains a major cause of childhood mortality and morbidity in most of the developing world, was eliminated in The Gambia by 2002 following the introduction of conjugate Hib vaccine in 1997. Formal disease surveillance was stopped in 2002 but five cases (including three of meningitis) were detected non-systematically between July 2005 and April 2006. This equates to an incidence of 3 per 100,000 annually for meningitis, a likely underestimate. The age distribution of cases (median 15 months, range 0-36 months) was older than previously seen and there were examples of apparent vaccine failure, but the cause for this re-emergence is not clear. No evidence was found of the emergence of a hypervirulent strain. The re-establishment of continuing surveillance is required to answer the questions raised by this report, and is particularly important in settings like The Gambia, where a booster dose is not given, to determine long-term effects of national immunisation with Hib vaccine.
authors.affiliation: Bacterial Diseases Programme, Medical Research Council Laboratories, P.O. Box 273, Banjul, Gambia. showie@mrc.gm
authors.forename: Stephen R C
authors.initials: SR
authors.lastname: Howie
authors.forename: Martin
authors.initials: M
authors.lastname: Antonio
authors.forename: Abiodun
authors.initials: A
authors.lastname: Akisanya
authors.forename: Sana
authors.initials: S
authors.lastname: Sambou
authors.forename: Ishrat
authors.initials: I
authors.lastname: Hakeem
authors.forename: Ousman
authors.initials: O
authors.lastname: Secka
authors.forename: Richard A
authors.initials: RA
authors.lastname: Adegbola
mesh_terms: D000293:Adolescent; D000328:Adult; D016667:Bacterial Capsules; D002648:Child; D005714:Gambia / Q000453:epidemiology; D006192:Haemophilus Infections / Q000453:epidemiology* / Q000517:prevention & control; D018073:Haemophilus Vaccines / Q000276:immunology*; D019741:Haemophilus influenzae type b; D006801:Humans; D015994:Incidence; D007223:Infant; D008297:Male; D008875:Middle Aged; D011135:Polysaccharides, Bacterial / Q000276:immunology*; D014611:Vaccination
chemical_list: D018073:Haemophilus Vaccines; C044237:Haemophilus influenzae type b polysaccharide vaccine; D011135:Polysaccharides, Bacterial