Epidemic meningitis and Meningitis

Epidemic meningitis noun - Meningitis caused by bacteria and often fatal.

Meningitis and epidemic meningitis are semantically related. In some cases you can use "Meningitis" instead a noun phrase "Epidemic meningitis".

Meningitis noun - Infectious disease characterized by inflammation of the meninges (the tissues that surround the brain or spinal cord) usually caused by a bacterial infection; symptoms include headache and stiff neck and fever and nausea.

Epidemic meningitis and meningitis are semantically related. Sometimes you can replace phrase "Epidemic meningitis" with "Meningitis", this terms are similar.