Chicken Pox (Varicella)

Chicken Pox (Varicella)

	Chicken Pox (Varicella) This is among the most communicable of diseases caused by varicella zoster virus. The virus belongs to herpes virus group. It is a double stranded virion with icosahedral symmetry and 162 capsomeres. In adults the same virus causes herpes zoster (shingles). Virus is transmitted chiefly by droplets and skin contact.
There is in the beginning fever, anorexia and headache, when virus multiplies in the respiratory tract. When it passes to the blood stream and localises in the peripheral nerves and skin, it multiplies rapidly in cutaneous tissues. This results in the development of fluid-filled, tear-drop shaped skin lesions called vesicles. The vesicle contains large amount of virus laden, highly infectious fluid. Later, after 3-4 days, they break open, forming crusts which become dry.
The lesions are larger than those of small pox. The disease becomes serious, if lungs (in which pneumonia may develop) or brain (encephalitis) are involved. Secondary infections of skin by bacteria may also occur: Adenine arabinoside-A (Ara-A), a nucleic acid substitute has shown good results in the treatment.
In Japan a vaccine is also developed Herpes zoster (shingles) in adults is a painful disease in which the virus multiplies in the ganglia along the spinal cord and then passes down the nerves of trunk to the skin. There is superficial tingling and burning sensations in the skin with blotchy red patches