S.pneumoniae meningitis featured in Question 9 from the first paper of 2013, as one of the septic complications of the post-splenectomy state. Specifically, the college examiners were interested in predisposing risk factors and specifics of management.
For the time-poor reader, LITFL has an excellent overview of adult bacterial meningitis.
Predisposing factors to pneumococcal meningitis:
- Extremes of age (very young and very old)
- Intracranial implants, eg. cochlear implants
- A CSF leak, for any reason
- Cochlear implants
- Sickle cell disease
- Unvaccinated patient
Features suggesting a poor outcome:
Apparently, even now this condition has a disturbingly high mortality - almost 30%.
The following seem to be factors associated with a high risk of death:
- Cranial nerve palsies
- Low GCS
- A raised ESR
- High CSF protein
- Low CSF leucocytes (less than 1000 per ml)
Utility of the urinary antigen
The urinary antigen in meningitis has a lower sensitivity than in pneumococcal pneumonia.
In pneumonia, the sensitivity is 82% and specificity is 97%.
In meningitis, the sensitivity is about 57% (but it is still highly specific).
However, it looks like you can use it on the CSF. In fact, the sensitivity improves to 95% if you decide to do this. Not all laboratories are going to agree with this.
Immediate management should consist of dexamethasone, vancomycin and ceftriaxone.