A variety of diseases caused by viruses in the Herpesveridae family fall under the name herpes. Different types affect both animals and humans. In humans, Herpesveridae cause oral and genital herpes, chickenpox and shingles, cytomegalovirus, infectious mononucleosis, and Kaposi's sarcoma and other cancers. Eight viruses in this family can cause disease in humans, and all produce life-long infections, though they may produce symptoms only sporadically or be asymptomatic.
Herpes simplex virus (HSV) I and II are responsible for oral and genital infections, with HSV-I more likely to cause orofacial symptoms and HSV-II more likely to cause genital symptoms. Both viruses infect the nervous system. If symptomatic, they produce small painful blisters on the affected area that become scabs as they heal. Both types are transmitted through skin-to-skin contact with an infected person.
Varicella zoster virus (VZV) causes chickenpox and shingles, and it is also called herpes zoster. Chickenpox begins as a rash, which is followed by the formation of small, itchy blisters on the body and scalp. It is contagious and remains in the nervous system for life, though it rarely has serious complications. VZV infection is typically more serious in adults than in children, and it may progress to shingles, which is characterized by headache, malaise, fever, and pain, in addition to blisters. In severe cases, the patient may develop postherpetic neuralgia, characterized by long-lasting, severe pain that is often difficult to manage.
Epstein-Barr virus (EBV) is extremely common, but usually asymptomatic. It most often causes infectious mononucleosis (mono), which presents as sore throat, fever, and fatigue. Infectious mononucleosis is spread via saliva and is self-limiting, meaning it can usually be resolved without treatment. Rare and potentially fatal complications occur in 5% of all cases. EBV and Kaposi's sarcoma-associated herpesvirus (KSHV), which causes Kaposi's sarcoma and other tumors, both affect the immune system and remain in the B-cells while latent.
Cytomegalovirus (CMV) causes symptoms similar to infectious mononucleosis, and is spread through bodily fluids. It is treated with an immunoglobulin injection, sometimes in combination with an antiviral. Roseolovirus, also spread through bodily fluids, is the cause of the childhood disease rolseola, characterized by rash, high fever, respiratory symptoms, irritability, and decreased appetite. Roseola usually resolves on its own. Both CMV and roseolovirus reside in the T-cells of the immune system when latent, and both can be life-threatening in infants and patients with compromised immune systems.
