– Herpes simplex viruses (human herpesviruses types 1 and 2) commonly cause recurrent infection affecting the skin, mouth, lips, eyes, and genitals. Herpes simplex virus type 2 (HSV-2) infection is responsible for significant neurological morbidity, perhaps more than any other virus. Herpes simplex virus type 2–associated neurological disease may result from primary infection or reactivation of latent HSV-2. Common severe infections include encephalitis, meningitis, neonatal herpes, and, in immunocompromised patients, disseminated infection.