Both the inflammatory response and clinical outcome differ markedly between adults with pneumococcal and meningococcal meningitis in a high HIV-1 prevalent setting in sub-Saharan Africa

Outcomes from pneumococcal meningitis (PM) are worse than meningococcal meningitis (MM), particularly in settings with high HIV-1 prevalence, but the reasons are unknown. We compared inflammatory responses between PM and MM in Malawian adults. As compared to MM (n=27, 67% HIV-infected, mortality 11%), patients with PM (n=440, 84% HIV-infected, mortality 54%) were older, had strikingly lower CSF WCC, higher pro-inflammatory cytokine concentrations and higher mortality. PM is characterized by significantly lower CSF WCC, but greater inflammation and higher mortality compared to MM. Mechanistic understanding of blunting of the CSF leukocyte response in PM in-vivo is required.