title: Which contacts of patients with meningococcal disease carry the pathogenic strain of Neisseria meningitidis? A population based study.
abstract: OBJECTIVE
  To determine the prevalence of the pathogenic strain of Neisseria meningitidis in contacts of patients with meningococcal disease, and to determine which contact groups are likely to be carriers and warrant chemoprophylaxis.
  
  
  METHODS
  Population based study.
  
  
  METHODS
  Norwegian county of Telemark.
  
  
  METHODS
  1535 primary contacts of 48 patients with meningococcal disease, and 78 secondary contacts.
  
  
  METHODS
  Carriers of the pathogenic strain were treated with rifampicin. All household members and kissing contacts under 15 years of age were treated with oral penicillin. Contacts were taught to recognise the symptoms of meningococcal disease.
  
  
  RESULTS
  In 27 of 48 cases investigated, contacts carrying the pathogenic strain of N meningitidis were found. A total of 42 such contacts were identified. Contacts were stratified into three classes according to the assumed closeness of contact with patients. In class 1 (household members and kissing contacts) the prevalence of the pathogenic strain was 12.4% (95% confidence interval 5.5% to 19.3%). In classes 2 and 3 the prevalence was 1.9% (0.9% to 3.4%) and 1.6% (0.14% to 3.1%).
  
  
  CONCLUSIONS
  There is a high rate of carriage of the pathogenic strain of N meningitidis in patients' household members and kissing contacts, and this supports the practice of giving chemoprophylaxis to these contacts. The prevalence of carriage among other contacts is 2-3 times that found in the general population (0.7%); the benefits of chemoprophylaxis to these contacts may be marginal.
authors.affiliation: Department of Medical Microbiology, University of Tromso, 9037 Tromso, Norway. bjorneri@online.no
authors.forename: B E
authors.initials: BE
authors.lastname: Kristiansen
authors.forename: Y
authors.initials: Y
authors.lastname: Tveten
authors.forename: A
authors.initials: A
authors.lastname: Jenkins
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000904:Antibiotics, Antitubercular / Q000627:therapeutic use; D002353:Carrier State / Q000453:epidemiology*; D002648:Child; D002675:Child, Preschool; D016358:Contact Tracing; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D008589:Meningococcal Infections / Q000453:epidemiology* / Q000517:prevention & control; D008875:Middle Aged; D009345:Neisseria meningitidis / Q000302:isolation & purification; D009664:Norway / Q000453:epidemiology; D010614:Pharynx / Q000382:microbiology; D011159:Population Surveillance; D015995:Prevalence; D012293:Rifampin / Q000627:therapeutic use
chemical_list: D000904:Antibiotics, Antitubercular; D012293:Rifampin