title: Clinical diagnoses and outcomes of 4619 hospitalised cases of laboratory-confirmed invasive meningococcal disease in England: Linkage analysis of multiple national databases.
abstract: Invasive meningococcal disease (IMD) is rare but remains one of the most feared infectious diseases worldwide. We linked multiple national datasets to describe disease characteristics and outcomes of IMD in England over a five-year period.
  
  
  
  IMD cases confirmed by Public Health England (2007-11) were linked with national hospitalisation records and death registrations. Cases were analysed by age, gender, capsular group, clinical presentation, diagnostic test and outcome. Risk factors for death were assessed using multivariable logistic regression.
  
  
  
  Overall, 4619 of 5115 (90.30%) laboratory-confirmed IMD cases were successfully linked to a hospitalisation record. Group B meningococci were responsible for 87.33% (n = 4034) of hospitalised IMD cases, ranging from 93.56% (2294/2452) in <15 year-old to 53.52% (152/284) among ≥65 year-old. Most cases presented with meningitis only (n = 2057, 44.53%), septicaemia only (n = 1725, 37.35%) or both meningitis and septicaemia (n = 389, 8.42%). Over half the cases (2526/4619, 54.69%) were confirmed by PCR only, 22.91% (1058/4619) by culture only and 22.41% (1035/4619) by both. The case fatality rate was 4.46% (206/4619; 95% CI, 3.88-5.10%) and varied by age, clinical presentation and capsular group. Children under 15 years who died within 30 days of diagnosis were significantly more likely to have been diagnosed by culture than by PCR alone (OR, 1.56; 95% CI, 1.02-2.39; P = 0.040).
  
  
  
  We identified complex interactions between age, meningococcal capsular group, clinical presentation, diagnostic method and death. The recent introduction of two new meningococcal immunisation programmes in the UK should significantly reduce IMD cases and deaths in the coming years.
authors.affiliation: Public Health England, South East Health Protection Unit, Parkside, Horsham, West Sussex RH12 1RL, UK.
authors.forename: Chantal
authors.initials: C
authors.lastname: Edge
authors.affiliation: Immunisation Department, Public Health England, 61 Colindale Avenue, London NW9 5EQ, UK.
authors.forename: Pauline
authors.initials: P
authors.lastname: Waight
authors.affiliation: Immunisation Department, Public Health England, 61 Colindale Avenue, London NW9 5EQ, UK.
authors.forename: Sonia
authors.initials: S
authors.lastname: Ribeiro
authors.affiliation: Meningococcal Reference Unit, Public Health England, Clinical Sciences Building 2, Manchester Royal Infirmary, Oxford Road, Manchester M13 9WL, UK.
authors.forename: Ray
authors.initials: R
authors.lastname: Borrow
authors.affiliation: Immunisation Department, Public Health England, 61 Colindale Avenue, London NW9 5EQ, UK.
authors.forename: Mary
authors.initials: M
authors.lastname: Ramsay
authors.affiliation: Immunisation Department, Public Health England, 61 Colindale Avenue, London NW9 5EQ, UK; Paediatric Infectious Diseases Research Group, St. George's University of London, Cranmer Terrace, London SW17 0RE, UK. Electronic address: shamez.ladhani@phe.gov.uk.
authors.forename: Shamez
authors.initials: S
authors.lastname: Ladhani
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D002648:Child; D002675:Child, Preschool; D016208:Databases, Factual; D004739:England / Q000453:epidemiology; D005260:Female; D006760:Hospitalization; D006801:Humans; D015994:Incidence; D007223:Infant; D016015:Logistic Models; D008297:Male; D008498:Medical Record Linkage; D008589:Meningococcal Infections / Q000175:diagnosis / Q000453:epidemiology* / Q000382:microbiology* / Q000517:prevention & control; D022401:Meningococcal Vaccines; D008875:Middle Aged; D009345:Neisseria meningitidis / Q000302:isolation & purification; D016133:Polymerase Chain Reaction; D012307:Risk Factors; D018805:Sepsis / Q000382:microbiology; D055815:Young Adult
chemical_list: D022401:Meningococcal Vaccines
keywords: Data linkage; Meningococcal disease; Outcomes; Risk factors; Vaccine