Community-acquired Haemophilus influenzae meningitis in adults

•H. influenzae causes 4% of community-acquired bacterial meningitis cases in adults.•Majority adult H. are caused by non-typeable serotypes.•Predisposing conditions ENT infections, CSF leakage or immunocompromised state.•Unfavourable outcome adults occurs 17%. BackgroundHaemophilus is an uncommon cause adults.MethodsWe analyzed episodes included a prospective nationwide cohort study the Netherlands.ResultsFrom 2006 to July 2018, 82 2272 (4%) were (mean annual incidence 0.5 patients per 1,000,000). Median age was 61 years (IQR 46–68), and 48 (59%) occurred woman. Predisposing factors otitis and/or sinusitis 33 76 (49%), immunocompromising 19 75 (25%) cerebrospinal fluid leak 13 79 (17%). Serotyping showed 63 80 isolates (79%) (NTHi). Three died 14 (17%) had unfavorable (Glasgow Outcome Scale score < 5 at discharge). Pneumonia (odds ratio [OR] 5.8, 95% confidence interval [95%CI] 1.1–30.8), presence (OR 6.0, 95%CI 1.5–24.4), seizures on admission 10.7, 1.6–72.8) associated with outcome, while NTHi favorable 5.6, 1.6–19.5).ConclusionH. mainly causing disease those predisposing factors, such as leakage, state. In majority strains. Haemophilus adults. We Netherlands. From 1.6–19.5).