Haemophilus influenzae meningitis in adults

Community-acquired Haemophilus influenzae meningitis in adults

BACKGROUND

Haemophilus influenzae is an uncommon cause of meningitis in adults.

METHODS

We analyzed episodes of community-acquired H. influenzae meningitis in adults included in a prospective nationwide cohort study in the Netherlands.

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). 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).

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.

Probable acute disseminated encephalomyelitis due to Haemophilus influenzae meningitis

We report the case of a 17-year-old male on long-term steroid therapy for minimal lesion glomerulopathy who, after an upper respiratory infection, presented with Haemophilus influenzae type b meningitis. Twenty-four hours later he developed depression of consciousness which progressed to coma and left hemiparesis. Brain magnetic resonance imaging (MRI) revealed multiple lesions (hyperintense on T2 and slightly hypointense on Tl) involving mainly white matter suggestive of inflammation. MRI features were compatible with acute disseminated encephalomyelitis (ADEM), although a differential diagnosis included cerebritis or vasculitis, secondary to bacterial meningitis. The patient was treated with high-dose steroids which resulted in a gradual improvement followed by complete clinical recovery. We propose a diagnosis of ADEM was the best diagnosis because of the radiological features and response to steroids. The occurrence of ADEM associated with acute meningitis, however rare, represents an important diagnostic challenge for the clinician.

Community-acquired Haemophilus influenzae meningitis in adults

Haemophilus influenzae is an uncommon cause of bacterial meningitis in adults. This report describes a prospective evaluation of 16 episodes of community-acquired H. influenzae meningitis in a nationwide study on bacterial meningitis. Predisposing conditions were present in eight (50%) of the 16 episodes; the most common predisposing conditions were otitis or sinusitis (five episodes; 31%) and remote neurosurgery or head trauma (three episodes; 19%). One (6%) episode was fatal and hearing loss occurred in four (25%) episodes. It was concluded that H. influenzae meningitis in adults is a disease with a rather benign clinical course and a relatively good prognosis compared with pneumococcal meningitis.

Community-acquired bacterial meningitis in adults: the epidemiology, timing of appropriate antimicrobial therapy, and prognostic factors

Between January 1986 and December 1999, 109 adult patients with culture-proven community-acquired bacterial meningitis were identified at Kaohsiung Chang Gung Memorial Hospital. To compare changes over time, the appearance of disease among our patients was divided into two equal time periods: an earlier time period (1986-1992) and a later time period (1993-1999). In this study, there was a decreasing proportion of community-acquired bacterial meningitis compared with nosocomial bacterial meningitis in adult patients in recent years. Its proportion declined dramatically from 81% in the earlier 7 years to 37% in the later 7 years. Of the pathogens, Klebsiella (K.) pneumoniae was the most frequently implicated pathogen, followed by Viridans (V.) streptococci, Streptococcus pneumoniae, and Staphylococcus aureus. Other rare organisms including Acinetobacter baumannii, Salmonella Group B and D, Proteus mirabilis, Group B, D, and non-A, non-B and non-D streptococci, and coagulase-negative staphylococci emerged during the second period. There was a decrease in the mortality rate from 44% in the first to 34% in the second time period, but the overall mortality rate remained high. Of the implicated pathogens, patients infected with V. streptococci had a consistently favorable prognosis, while a dramatic decrease in the mortality rate of those infected with K. pneumoniae was seen in recent years. In the multiple logistic regression analysis, only the presence of septic shock and seizures was independently associated with mortality. The timing of appropriate antimicrobial therapy, as defined by consciousness level, was a major determinant of survival and neurological outcomes for patients with community-acquired bacterial meningitis, and the first dose of an appropriate antibiotic should be administrated before a patient's consciousness deteriorates to a Glasgow coma scale score lower than 10.

Adult bacterial meningitis in Southern Taiwan: epidemiologic trend and prognostic factors

In two investigative phases over a 13.5-year study period (January 1986-June 1999), 202 adult patients with culture-proven bacterial meningitis were enrolled in this study. In order to determine the epidemiologic trend, prognostic factors and therapeutic results for this disease. Klebsiella pneumoniae (K. pneumoniae), Pseudomonas aeruginosa, and Streptococcus pneumoniae were the three most commonly revealed pathogens, accounting for about 48% of the episodes. Although there was a change in relative frequency for the pathogens, K. pneumoniae remained the most prevalent during the two periods studied (January 1986-December 1992 and January 1993-June 1999). Multiantibiotic resistant strains have been in evidence since their appearance in 1994, with most of our patients acquiring their infection nosocomially. The overall mortality rates during the two periods were 40% and 34%, respectively. In stepwise logistic regression analysis, only initial conscious level, appropriate antibiotic therapy and septic shock were independently associated with mortality, after adjustment for other potentially confounding factors. Initial empirical antibiotics with both third-generation cephalosporin and penicillin G, should be considered for the majority of meningitis cases resulting from infection with Gram-negative bacilli and streptococcal species. Besides the evolution of newer pathogens, there has been increasing incidence for nosocomially acquired bacterial meningitis for patients postneurosurgery, with the emergence of resistant strains presenting a therapeutic challenge in recent years. Vancomycin and imipenem/cilastatin should be considered as the initial empirical antibiotics of choice for the treatment of this special group of patients.