[Haemophilus influenzae type a as the causative agent of meningitis in an infant].

A 6-month-old girl had been ill with a cold for several days and was increasingly drowsy. She had been fully vaccinated against Haemophilus influenzae type b and had meningitis due to H. influenzae type a. She made a complete recovery after treatment with ceftriaxone and amoxicillin. In the Netherlands, vaccination with the conjugated H. influenzae type b vaccine was started in 1993 and since then invasive infections caused by H. influenzae type b have almost disappeared. Vaccination may suppress carriership of H. influenzae type b. However, vaccination does not elicit cross-protective antibodies against other serotypes of H. influenzae. H. influenzae non-type b may profit from the vaccination state, resulting in a higher carrier rate and an increased incidence of invasive infections. In the Netherlands, H. influenzae type a as the causative agent of an invasive infection has been recorded for the first time since registration started in 1975 and since then five such cases have been reported. In the literature, 45 cases of infection with H. influenzae type a have been described up until now.