· Shingles and chicken pox were once thought to be separate illness however researchers now know that they are both caused by a virus of the herpes family known as Varicella zoster virus. Varicella: primary infection that causes chicken pox. Herpes zoster: reactivation of the varicelle zoster virus that causes shingles. Shingles often occurs many years after the initial chicken pox infection in people.
· Most healthy people who are infected by Cytomegalovirus after birth have no symptom however some may go on to develop an infectious mononucleosis (aka glandular fever) with prolonged fever and a mild hepatitis. Cytomegalovirus can be found in bodily fluids of any infected person and can be found in urine, saliva, blood, tears, semen and breast.
· Epstein - Barr virus (EBV): people who are infected with EBV is often asymptomatic but infection usually cause infectious mononucleosis. EBV can found in nasopharynx and in salivary gland.

Clinical Features- Herpes simplex
The symptoms vary based on the stage of the virus, the primary outbreak and recurrence. Both herpes simplex viruses 1 and 2 produce similar symptoms however they can differ in severity depending on the site of infection.
· General symptoms of primary herpes simplex infection: skin eruptions appear 2 to 12 days after the initial exposure to the virus. (skin lesion)
· Asymptomatic stages: after an outbreak, the herpes simplex virus becomes latent where HSV produces no symptoms at all and the virus is not transmissible.
· Symptoms of recurrence: the outbreak of infection is often preceded by an early group of symptoms such as itching skin, pain or abnormal tingling sensation at site of infection.

· Oral herpes such as cold sores is usually caused by HSV1 but can also be caused by HSV2. It usually affects the lips, blister form on the lips but may also erupt on the tongue.
· Genital herpes typically affects the penis, vulva or rectum and is usually caused by HSV2 although the stastistic of HSV1-genital infection is increasing. Symptoms include blister, burning sensation and discharge for 1 to 3 weeks.

Clinical features- Varicella zoster
· Symptoms of varicella (chicken pox): fever, skin lesion all over body, scratching the lesion can lead to secondary infection and causes scarring. Chicken pox is dangerous in pregnant woman as the virus can be passed onto the baby and causes problem include birth defects such as scars, eye problems and shortened limbs, etc.
· Shingles: after the chicken pox virus has been contracted, it travels from the skin along the nerve paths to the roots of the nerves where is becomes latent. If it reactivates, there is a burning sensation on the nerve paths along which the virus is travelling, follow by rash which is accompanied by fever and enlarged lymph nodes.

Lab diagnosis
· The herpesvirus can be identify by culturing the virus where cells or fluids from a fresh sore are collected. A viral culture is the best method of identifying a genital herpes infection.
· ELISA (Enzyme-Linked ImmunoSorbent Assay) is a technique used mainly to detect the presence of antigen in a sample.
· Antibody test: blood tests can find antibodies that are made by the immune system to fight a herpes infection.

Epidemiology and control of Herpes simplex viruses
· Almost 100% of the adult population is at risk of HSV1 due to kissing and close proximity.
· Up to 20% of the US population are infected with HSV2 mainly by sexual contact.
· To prevent risk of transmission: don’t kiss, practice safe sex and refrain from risky behaviour.

Epidemiology and control of Varicella zoster
· Chicken pox can be prevented by vaccination.
· Avoid people who are infected by chicken pox.

By: man hua.