Epidemiology and Infection

Acquisition and carriage of meningococci in marine commando recruits

a1 Public Health Laboratory, Church Lane, Heavitree, Exeter EX2 5AD
a2 Public Health Laboratory, Gloucestershire Royal Hospital, Great Western Road, Gloucester GL1 3NN
a3 PHLS Statistics Unit, 61 Colindale Avenue, London NW9 5EQ
a4 PHLS CDSC South & West, Public Health Laboratory, Gloucestershire Royal Hospital, Great Western Road, Gloucester GL1 3NN
a5 PHLS Meningococcal Reference Unit, Public Health Laboratory, Withington Hospital, Manchester M20 8LR
a6 Commando Training Centre, Royal Marines, Lympstone, Devon EX8 5AR
a7 Royal Naval Hospital, Gosport, Hants PO12 2AA; now: Kidderminster General Hospital, Bewdley Road, Kidderminster, Worcestershire DY11 6RJ


Meningococcal acquisition is a prerequisite for invasive disease. Three hundred and eleven male marine commando recruits were studied throughout 29 weeks of basic training to identify factors influencing meningococcal carriage and acquisition including troop number, season, smoking, respiratory infection, antibiotic usage and nasopharyngeal bacterial interference flora.

A high carriage rate on entry to training (118/311, 37·9%) and subsequent sustained high rates of meningococcal acquisition were found. Of the potential factors examined, only active and passive smoking were found to be associated significantly with meningococcal carriage on entry. The association between active smoking and meningococcal carriage was dose-dependent, with odds ratios (OR) of 2·2 (95% CIs 1·0–4·8) and 7·2 (95% CIs 2·3–22·9) for light and heavy smokers respectively. Passive smoking predisposed independently to carriage (OR 1·8, 95% CIs 1·1–3·0). Active and passive smoking combined to give an attributable risk for meningococcal carriage of 33%. In contrast, despite a high and sustained rate of meningococcal acquisition in the study population, none of the risk factors investigated, including active smoking, was associated significantly with meningococcal acquisition. No cases of meningococcal disease occurred during the 16-month study period. Therefore smoking may increase the duration of meningococcal carriage rather than the rate of acquisition, consistent with the increased risk of meningococcal disease from passive as opposed to active smoking. Public health measures that reduce the prevalence of smoking should reduce the risk of meningococcal disease.

(Accepted July 18 1998)

c1 Author for correspondence.