The most commonly identified viruses causing sporadic cases of acute encephalitis in adults are herpesviruses (HSV, VZV, EBV). Note Frequently Asked: Enteroviruses (coxsackieviruses, echoviruses, and human enteroviruses 68-71) are the most commonly identified viruses causing sporadic cases of acute meningitis. Ref: Roos K.L., Tyler K.L. (2012). Chapter 381. Meningitis, Encephalitis, Brain Abscess, and Empyema. In D.L. Longo, A.S. Fauci, D.L. Kasper, S.L. Hauser, J.L. Jameson, J. Loscalzo (Eds), Harrison's Principles of Internal Medicine, 18e