Community-acquired Haemophilus influenzae meningitis in adults

Nora Chekrouni,Diederik L.H Koelman,Matthijs C Brouwer,Arie Van Der Ende,Diederik Van De Beek

doi:10.1016/j.jinf.2021.03.016

Abstract

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

Highlights

Haemophilus influenzae (H. influenzae) is a commensal bacterium of the human upper respiratory tract, and can cause a wide range of localized and invasive infections in humans, such as epiglottitis, pneumonia, septicemia, and meningitis.[1]
A total of 82 of 2272 episodes (4%) of confirmed communityacquired bacterial meningitis, all occurring in unique patients, were caused by H. influenzae (Supplementary Data; supplementary Figure 1)
CSF leak was present in 11 of 79 (14%) patients, all being caused by a nontypeable (unencapsulated) H. influenzae strains (NTHi), of which 7 patients (64%) had a history of bacterial meningitis

Summary

Introduction

Haemophilus influenzae (H. influenzae) is a commensal bacterium of the human upper respiratory tract, and can cause a wide range of localized and invasive infections in humans, such as epiglottitis, pneumonia, septicemia, and meningitis.[1]. A cohort study of 16 adults with H. influenzae meningitis showed the disease had a benign clinical course and a relatively good prognosis.[10] In this study we describe the predisposing factors, clinical features,. Results: From 2006 to July 2018, 82 of 2272 (4%) bacterial meningitis episodes were caused by H. influenzae (mean annual incidence 0.5 patients per 1,000,000). Pneumonia (odds ratio [OR] 5.8, 95% confidence interval [95%CI] 1.1–30.8), presence of immunocompromising conditions (OR 6.0, 95%CI 1.5–24.4), and seizures on admission (OR 10.7, 95%CI 1.6–72.8) were associated with an unfavorable outcome, while NTHi was associated with a favorable outcome (OR 5.6, 95%CI 1.6–19.5). Conclusion: H. influenzae is an uncommon cause of adult bacterial meningitis patients mainly causing disease in those with predisposing factors, such as CSF leakage, ENT infections, and immunocompromised state. In adult patients the majority of H. influenzae meningitis is caused by non-typeable strains

Methods

Results

Conclusion