Herpes virus type 4 is also called Epstein-Barr virus. It typically causes infectious mononucleosis, a “kissing” disease. Symptoms include skin rash, fever, sore throat and swollen lymph glands. The virus can be involved in cancers like nasopharyngeal cancer. Herpes virus type 4 is contagious through bodily fluids, including saliva. Kissing, coughing, sneezing, or sharing utensils can make the infection spread.

The cell this virus targets is the B lymphocyte. These cells mature in the bone marrow and are a type of mononuclear leukocyte cells - white blood cells with a one-lobed nucleus. The incubation period for the Epstein – Barr Virus (EBV) is about 30 to 50 days, and patients typically have enlarged lymph nodes and spleens. Some patients have signs of hepatitis.


Human herpes virus 6 (HHV6) is a recently observed agent found in the blood cells of a few patients with a variety of diseases. It causes roseola (a viral disease causing high fever and a skin rash in small children) and a variety of other illnesses associated with fever in that age group. This infection accounts for many of the cases of convulsions associated with fever in infancy (febrile seizures).
"When you are having an outbreak of oral herpes, symptoms usually start with a burning, itching or tingling sensation on your lips," Michael says. "This will intensify until a small rash, and then blisters, appear. These sores are commonly called 'cold sores'. The blisters are usually filled with a clear or slightly yellow liquid. Over a short time, these blisters will burst leaving a painful, raw area. These will then dry and scab over. The scabs will generally fall off after a week or two, leaving fresh clear skin beneath."
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