Bacterial meningitis in immunocompromised patients

Bacterial meningitis is an acute infection of the meninges, in The Netherlands most commonly caused by Streptococcus pneumoniae and Neisseria meningitides. Risk factors for acquiring bacterial meningitis include a decreased function of the immune system. The aim of this thesis was to study occurrence, clinical features and outcome of adult bacterial meningitis in HIV-infected patients, solid organ transplant (SOT) recipients, hematopoietic stem cell transplantation (HSCT) recipients, people using immunosuppressive medication, diabetes patients and alcoholics. Patient were identified from a nationwide, prospective cohort study on bacterial meningitis.
Immunocompromised patients had a higher risk for acquiring bacterial meningitis as compared to the general population. The risk was 30-fold higher for HSCT recipients, 8.3-fold higher for HIV-infected patients, 7-fold higher for SOT recipients and 2-fold higher for diabetes patients.
Recognition of meningitis was shown to be difficult owing to atypical clinical manifestation for especially SOT recipients and patients using immunosuppressive medication.
S. pneumoniae was the most frequently encountered pathogen, however, patients using immunosuppressive medication had a high risk of listeria meningitis.
Outcome was similar in patient with and without HIV infection. An unfavorable outcome occurred in 67% of SOT recipients, 58% of alcoholic patients, and 50% of HSCT recipients. Diabetes was found to be a strong independent risk factor for death in community-acquired bacterial meningitis with an odds ratio of 1.63.
In conclusion, immunocompromised patients differ in occurrence, clinical features and outcome form the general population and treating physicians should be aware of these differences.