* What it is: Meningitis, an inflammation of the membranes that cover the brain and spinal cord, is a life-threatening illness caused by bacteria, viruses, parasites and fungi. Bacterial meningitis, such as that in Staunton, Va., is fatal for about 5 percent of its victims even if they are treated with antibiotics. Viral meningitis is somewhat less serious.
* Who is at risk: Meningitis often strikes young and otherwise healthy individuals, particularly those who are in close contact with each other, such as kindergarten pupils or soldiers living in barracks. The bacteria is typically passed by asymptomatic "carriers" who, although immune themselves, nevertheless have the bacteria living in their nose or throat.
* How it is passed: The bacteria enter the body through the nose or throat, causing an infection that may amount to a sore throat. Coughing, sneezing, kissing and sharing food can pass the disease. There are vaccines for some types of the bacteria, but not for others.
* Symptoms: Like influenza, meningitis usually begins with a headache, muscle aches and fever, and it can involve nausea, vomiting and drowsiness. If the bacteria enter the bloodstream, they can produce a rash that resembles small bruises. If it is not treated rapidly with penicillin, reduced blood pressure and shock can follow, leading to death.
* Treatment: The antibiotic Rifampin is used to kill the bacteria carried in the nose and throat. Penicillin is effective in killing the bacteria once they leave the nose and throat and invade body tissues. Paradoxically, neither drug works in place of the other.