Epidemiology and Infection

Research Article

Epidemiology of invasive Haemophilus influenzae infections in England and Wales in the pre-vaccination era (1990–2)

E. C. Andersona1, N. T. Begga2, S. C. Crawshawa2, R. M. Hargreavesa1 c1, A. J. Howarda3 and M. P. E. Slacka1

a1 Oxford Public Health Laboratory, Oxford Radcliffe Hospital, Oxford

a2 PHLS Communicable Disease Surveillance Centre, Colindale

a3 Gwynnedd Hospital, Bangor, North Wales

Summary

This survey defined the pattern of invasive Haemophilus influenzae infections during 1990–2 in six regions in England and Wales during the pre-vaccination era providing a baseline against which any changes in patterns of disease due to the introduction of the Haemophilus influenzae type b vaccination programme can be monitored. A total of 946 cases of invasive Haemophilus influenzae were recorded during the survey period of which almost 90 % were due to type b and most of the remainder were non-typeable. Type b infections occurred predominantly in children less than 5 years of age (88%) with the highest attack rate in male infants in the 6–11 month age group. Diagnostic category varied with both age and serotype; meningitis was the commonest presentation overall but pneumonia and bacteraemia were more common in adults and non-typeable isolates. Mortality was highest in neonates and the elderly (over 65 years of age) who were more likely to have an underlying predisposing condition than older children and adults. Children under 5 years of age had a higher case fatality rate for non-typeable than for type b infections. Ampicillin resistance was 15% and there were no cefotaxime resistant type b isolates.

(Accepted February 06 1995)

Correspondence:

c1 Author for correspondence: Dr R. M. Hargreaves, Oxford Public Health Laboratory, Oxford Radcliffe Hospital, Headington, Oxford OX3 9DU.

Footnotes

† Prepared on behalf of the Haemophilus Working Group of the Public Health Laboratory Service.

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