When a panel of cytokines (including GM-CSF, IFNγ, IL-1α, IL-1β, IL-1ra, IL-2, IL-4, IL-6, IL-8, IL-10, IL-12, IL-18, and TNF-α) was measured in saliva from healthy pigs and in pigs with meningitis and S. suis infection, upregulation of several cytokines was observed in the diseased animals. Here, IL18 is linked to infectious meningitis.