Which contacts of patients with meningococcal disease carry the pathogenic strain of Neisseria meningitidis? A population based study.
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.
Kristiansen
B E
BE
Department of Medical Microbiology, University of Tromso, 9037 Tromso, Norway. bjorneri@online.no
Tveten
Y
Y
Jenkins
A
A
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
D000904:Antibiotics, Antitubercular; D012293:Rifampin