VZV, or the varicella zoster virus, is one variety of the herpes virus. It commonly infects humans and is highly contagious but also very fragile and unable to persist for long in the environment or to survive cleaning with disinfecting agents. Initial infection with this virus typically takes the form of an outbreak of chicken pox, which, in most patients, subsides within a week. Subsequent recurrences of VZV generally manifest as shingles.
The chicken pox caused by VZV is only moderately dangerous when the disease is contracted by the young. It usually produces severe itching around a large number of sores over a relatively short period of time but has relatively few serious symptoms. Adult infection with VZV can produce more serious symptoms, with greater risk to the patient.
Parents would often arrange to have children spread chicken pox among their friends and playmates, in order to ensure that children would contract the disease when young, and thereby acquire immunity with a minimum of personal risk. The introduction of a vaccine against VZV in the 1990s offered an alternative to this practice, and vaccination swiftly became standard medical practice. Studies on the long-term efficacy of vaccination suggest that a program of vaccine boosters may be needed to confer lifetime immunity to VZV, but vaccination is certainly valuable, not least because patients who have been vaccinated need not worry about the appearance of shingles later in life.
A patient who has contracted this virus will never fully rid themselves of the infection. As with other varieties of the herpes virus, the varicella zoster virus takes up residence deep within the nervous system of a host. The virus is generally dormant and effectively contained by a healthy human immune system, but in some cases, especially when the immune system is weakened, the virus may re-emerge from dormancy. This re-emergence takes the form of shingles.
An outbreak of shingles normally causes patches of raised, itchy, and irritated skin, as the virus follows nerve pathways back to the surface. This is almost always limited to one side of the body because the human nervous system is split bilaterally, and the virus will normally only re-activate on one side. Shingles is typically not a severe condition but can be quite irksome and does lead to more serious complications in some patients, including viral infection of and damage to the eye or loss of nerve sensation in affected areas, caused by viral damage to the nervous system.
This virus can be treated with a number of anti-viral agents. As is typically the case, treatment with anti-viral drugs can boost immune response and greatly lessen symptoms. Treatment does not, however, completely destroy the viral infection in the body.