Human Herpes Virus Type 3

Human herpes virus 3(HHV-3) is one of eight herpes viruses known to infect humans. HHV-3 is an alpha-herpes virus and the cause of chickenpox (varicella) and shingles (zoster). Human herpes virus 3 is known by many names, including: varicella-zoster virus (VZV), chickenpox virus, varicella virus, and zoster virus (1).

HHV-3 is closely related to the herpes simplex virus (HSV), sharing much genome homology. All herpes viruses share similar properties, including the inactive periods that last for months to years. The known envelope glycoproteins (gB, gC, gE, gH, gI, gK, gL) correspond with those in HSV; however, there is no equivalent of HSV gD. HHV-3 also fails to produce the latency-associated transcripts that play an important role in establishing HSV latency (herpes simplex virus). HHV-3 virons are spherical and 150-200 nm in diameter. Their lipid envelope encloses the nucleocapsid of 162 capsomeres arranged in an icosaherdral form (2).

Background and Historical Perspective:

Herpes virus infections have been prevalent as early as the ancient Greek times. Hippocrates is known to have described the cutaneous spreading of herpes simplex lesions and scholars of Greek civilization define the Greek word "herpes" to mean "to creep or crawl" in reference to the spreading nature of the skin lesions. It was not until 1893 when Vidal recognized that human transmission of the Herpes Simplex infection from one individual to another. Human herpes virus 3 has a long recorded history (2). However, historical accounts often fail to distinguish between the poc marks caused by HHV-3 and those caused by small pox. The name chickenpox was thought to come about because the blisters look like peck marks caused by a chicken. It was only in the late eighteenth century that Heberden established a way to clinically differentiate between the two diseases. In 1888, it was suggested by van Bokay that chickenpox and herpes zoster were due to the same causal agent. It was not until Weller and Stoddard isolated the virus from both chickenpox and zoster and compared the viruses that this connection was confirmed: chickenpox and herpes zoster were indeed due to the same virus (2).

The United States would see up to four million cases of chickenpox along with 100 deaths from the virus annually, before the Varicella vaccine. The virus was also responsible for four hundred million dollars in medical expenses. The Varicella virus can come at any at any age, but throughout the twentieth century by ages nine or ten; eighty to ninety percent of American children have been infected. Studies from the Centers of Disease Control and prevention show that ninety percent of American adults are immune to the virus.

Today, about one hundred people a year die from chickenpox. Due to the advancement of medicine, there have been fewer hospitalizations for chickenpox. People most at risk are those with compromised