The human herpesvirus family is the source of many common diseases, including chickenpox, shingles, mononucleosis, cold sores and genital herpes. Infections caused by human herpesvirus tend to remain latent, which means they stay in the host even after the primary infection has resolved and can reactivate later. Meningitis is an inflammation of the protective membranes covering the brain and spinal cord. The inflammation may be caused by infection with viruses, bacteria, or other microorganisms, and less commonly by certain drugs.