Haemophilus influenzae infections among hospitalized adult patients

Background: Relatively few data are available about Haemophilus influenzae (Hi) infection among adults Materials and Methods: We studied all adult patients with Hi infection hosp italized between 1988 and 1997 at the University Hospital of Berne. Data we re abstracted retrospectively from clinical charts and microbiology records using a standardized questionnaire. Results: 12 invasive and 19 noninvasive Hi infections were observed during the study period. The main clinical manifestations were pneumonia (38.7%), bronchitis (29.0%) and meningitis (12.9%). Most patients (71.8%) had an und erlying condition. Lethality was high (22.6%), especially in pneumonia pati ents (50%). The frequency of meningitis caused by Hi serotype b (Hib) seeme d to decrease after 1990 when conjugated vaccines against Hib were introduc ed. Conclusion: Hi remains an important cause of lower respiratory and invasive disease associated with high lethality among polymorbid adult patients. Th e frequency of Hib infections may also decrease in adults due to herd immun ity induced by universal vaccination of children.