Human carriers are the only reservior of infection.
Endotoxin production is active with bacterial membrane fragments shed into the extracellular space. This leads to septic shock via relase of TNFa and IL-1. Patients who develop shock or DIC develop complications of infection such as infarct necrosis, cerebral edema and death. Deficiency of complement C5-C9 predisposes to infection. Gram stain of petechiae or buffy coat may show typical gram negative, bean-shaped diplococci.