PREDOMINANCE OF CERTAIN KLEBSIELLA CAPSULAR TYPES IN HOSPITALS IN THE UNITED-KINGDOM

Three hundred and fifty-seven strains of Klebsiella aerogenes sent from 357 different patients in 20 United Kingdom hospitals were capsular typed. Serotypes K21, K2 and K9 were most frequent and accounted for 42·0, 16·5 and 7·3 per cent respectively of all strains. A significantly large proportion of hospitals (14 out of 20) had isolates of K21, and this serotype, with K2, most commonly caused clusters of infection of four or more patients in individual hospitals within a four-week period. It is suggested that the prevalence of types K21, K2 and K9 reflects some unidentified epidemiological advantage that declares itself in clusters or epidemics of colonisation and infection in hospital patients. © 1979 The British Society for the Study of Infection.