The effects of mass immunization on Haemophilus influenzae type B-related orthopaedic disease.

Haemophilus influenzae type B has been responsible for a significant proportion of cases of septic arthritis in children in the past. This study looks at the effects of vaccination on childhood orthopaedic infection. Data were collected from 1988 by the Public Health Laboratory Services. Data were analysed with a two-sample t-test. A total of 16 of 17 cases were attributed to H. influenzae type B. Fourteen cases occurred in 5 years before mass immunization. Only two cases occurred in the 8 years following immunization. The incidence of H. influenzae septic arthritis in children has fallen significantly since the introduction of immunization (P=0.009). Vaccination has resulted in a significant fall in the incidence of H. influenzae type B septic arthritis in children.