Invasive Haemophilus influenzae type b disease in the Oxford region (1985-91).

Abstract

For a seven year period clinical and epidemiological data were prospectively collected on children aged <10 years with microbiologically confirmed invasive Haemophilus influenzae type b infection in the Oxford region to study the epidemiology of the disease and determine the potential impact of early primary immunisation in infints. Computer records of primary immunisations given to these cases were retrospectively analysed and, where necessary, hospital and general practitioner records were searched to determine the immunisation history.

Epidemiology of invasiveHaemophilus influenzaeinfections in England and Wales in the pre-vaccination era (1990–2)

“…H. inftuenzae infections which were identified in the regions under study. The organisation of the surveillance was as previously described for the Oxford [2] and Wales [3] At the reference laboratory the organism identification and antibiotic sensitivity pattern were investigated using a routine disk diffusion method and NCTC H.…”

“…There have been a number of epidemiological studies of H. influenzae infections worldwide; populations studied have included the UK [2,3], Northern Europe [6], the USA [7], Australia [8,9] and some developing countries [10]. They have shown wide variations in the annual incidence of invasive Hib disease but the consistent finding between the populations studied has been the increased risk of invasive disease in children less than 2 years of age (which correlates with their inability to produce anticapsular polysaccharide antibody) and the predominance of meningitis as the presenting condition.…”

“…There were 17 deaths in the elderly (over 65 years age). Nine were associated with an identified underlying predisposing condition: these included chronic respiratory condition (4 cases); cardiovascular condition (2); and malignancy (3). An underlying condition associated with death was more common in cases less than 12 months age (7 out of 10 (70 %) in whom a response was provided) and over 65 years of age (9 out of 11 (82 %)) than in the 1-64 years age group (9 out of 20 (45 %)).…”

“…In the UK it occurs with a peak incidence in infants less than 12 months of age [2,3], hence the introduction of an early childhood vaccination programme against the disease. Its commonest clinical manifestation in children is meningitis E. C. ANDERSON …”

Antibody persistence and Haemophilus influenzae type b carriage after infant immunisation with PRP-T

“…Although the highest incidence of invasive H influenzae type b infection in the era before the use of vaccine was recorded in children less than 2 years of age, considerable morbidity was also seen until 5 years of age and older 2. This age related susceptibility to H influenzae type b disease correlates with absent or low serum antibody concentrations to PRP 3…”