title: Prevalence of de-O-acetylated serogroup C meningococci before the introduction of meningococcal serogroup C conjugate vaccines in the United Kingdom.
abstract: Meningococcal serogroup C conjugate (MCC) vaccines have been introduced in the UK to combat the rise in serogroup C meningococcal disease. Serogroup C meningococci may occur naturally expressing either O-acetylated (Oac(+)) or de-O-acetylated (Oac(-)) polysaccharide capsules. In a small study in the USA in the 1970s 15% of serogroup C meningococcal case isolates were reported to be Oac(-) though the prevalence of these Oac(-) isolates has not been recorded in the UK. This is of interest as the first MCC vaccines to be introduced are Oac(+) and the potential impact of this on Oac(-) serogroup C isolates is unclear. Serogroup C isolates submitted to the Public Health Laboratory Service Meningococcal Reference Unit in January 1998 (n=113) and January 1999 (n=162) were investigated by dot blotting using monoclonals specific for Oac(+) and Oac(-) serogroup C polysaccharides. This revealed 12% Oac(-) isolates for both January 1998 and January 1999. The proportion of fatal cases was found to similar for both Oac(-) and Oac(+), 14 and 9% for 1998 and 5 and 3% for 1999, indicating that the pathogenic potential of these Oac(-) isolates is similar to Oac(+). The acetylation status of serogroup C isolates needs to be monitored throughout and after the introduction of MCC vaccines.
authors.affiliation: Meningococcal Reference Unit, Manchester Public Health Laboratory, Withington Hospital, Nell Lane, West Didsbury, M20 2LR, Manchester, UK. rborrow@nw.phls.nhs.uk
authors.forename: R
authors.initials: R
authors.lastname: Borrow
authors.forename: E
authors.initials: E
authors.lastname: Longworth
authors.forename: S J
authors.initials: SJ
authors.lastname: Gray
authors.forename: E B
authors.initials: EB
authors.lastname: Kaczmarski
mesh_terms: D000911:Antibodies, Monoclonal; D001428:Bacterial Vaccines; D006801:Humans; D015151:Immunoblotting; D008585:Meningitis, Meningococcal / Q000453:epidemiology / Q000382:microbiology*; D022401:Meningococcal Vaccines; D009345:Neisseria meningitidis / Q000737:chemistry / Q000145:classification*; D010641:Phenotype; D011134:Polysaccharides / Q000276:immunology; D015995:Prevalence; D012703:Serotyping; D006113:United Kingdom / Q000453:epidemiology; D018074:Vaccines, Conjugate
chemical_list: D000911:Antibodies, Monoclonal; D001428:Bacterial Vaccines; D022401:Meningococcal Vaccines; D011134:Polysaccharides; D018074:Vaccines, Conjugate; C410218:serogroup C meningococcal conjugate vaccine