Differences in the courses of meningococcal and pneumococcal cerebrospinal meningitis

Neisseria meningitidis and Streptococcus pneumoniae are the most common pathogens causing cerebrospinal meningitis (CSM) in adults. The mortality rate and the number of complications remain high. In our study, retrospective evaluations were conducted on data concerning 98 adult patients with bacterial cerebrospinal meningitis caused by Neisseria meningitidis (n = 42) and Streptococcus pneumoniae (n = 56), hospitalised at the Regional Specialistic Hospital in Wroclaw (Poland) within the period 1998-2018. Compared to the group infected with S. pneumoniae, patients infected with N. meningitidis were younger and were less often affected by an additional disease burden; they presented more frequently with haemorrhagic rashes. Compared to the S. pneumoniae group, in patients with meningococcal CSM, cytosis in cerebrospinal fluid measuring < 1,000 cells/ mL was less frequent; intravascular coagulation syndrome appeared more frequently; the hospitalisation time was shorter and the rate of mortality was lower. Meningococcal meningitis occurs more frequently among young people with no history of disease. It is characterised by the rapid development of symptoms, which results in earlier diagnosis and more favourable prognosis compared to cases of S. pneumoniae. Irrespective of the pathogen, advanced age and a level of cytosis in cerebrospinal fluid of < 1,000 cells /μl indicate an unfavourable prognosis.