Published online by Cambridge University Press: 15 May 2009
1. The nasal carriage of Staph. aureus and its relation to disease was studied in new recruits, boy apprentices and trained men of the Royal Air Force.
2. The proportions of Staph. aureus that were penicillin-resistant ranged from 15% in new recruits to 29% in trained men. In a school for apprentices the rate in new arrivals was 18%, and 23% for boys after the initial training. We were unable to find when these changes occurred.
3. 31% of strains isolated from septic lesions were penicillin-resistant and the rate was similar in all types of unit. Resistant strains were not apparently more virulent than sensitive strains.
4. About 1% of all strains isolated were resistant to tetracycline and streptomycin and much smaller proportions to chloramphenicol and erythromycin.
5. The phage-group distribution was similar for nasal and lesion strains, but nearly half the penicillin-resistant lesion strains belonged to Group I, and types 52A and 3C/55/71 were much commoner in lesions than in the nose.
6. Penicillin-resistant strains were more readily acquired and more rapidly lost than the sensitive strains.
7. Nasal carriers suffered from septic lesions more frequently than non-carriers, and those with a lesion tended to suffer further lesions. There was no evidence of cross-infection among bedroom contacts.
8. The proportion of penicillin-resistant strains rose from 30 to 40% between admission to and discharge from service hospitals. Resistant strains were not carried for long after discharge.
9. Penicillin treatment resulted in a fall in the total carrier rate and a rise in the resistance rate. Phage type analysis showed that this was mainly due to elimination of sensitive strains and recolonization with resistant strains.
We are greatly indebted to Miss Susan Green for the large amount of work that she did in the laboratory. We should like to thank also many Royal Air Force medical officers for their assistance, in particular Wing Commander E. S. Odbert, Wing Commander M. White, Squadron Leader M. Shearer and Flight Lieutenant A. J. Zuckerman; and the Director-General of the Royal Air Force Medical Services for permission to publish the results.