| |
Unique Home Furniture, Home Decorating and Home Decoration Store
Produces Disease: Cause. The virus that produces chicken pox a tiny particle about 0.22 microns in diametf (One micron equals about Vi>5,ooo of an inch Because it appears to be identical with the vir that causes herpes zoster (an inflammatory di ease of the nerves, also known as shingles, th produces small, blisterlike skin eruptions), it frequently referred to as the varicella-zoster (V-I virus, and doctors believe that chicken pox an herpes zoster are actually two different forms ( the same disease. This theory is supported b cases showing that children have develope chicken pox after being exposed to adults wit herpes zoster. Chicken pox develops when child is first infected with the V-Z virus. Whe the disease subsides the virus remains in th body in a latent, or inactive, form and may, fo unknown reasons, become activated and produo herpes zoster many years later.
Mycoplasmosis is a respiratory disease caused y the bacteria Mycoplasma gallisepticum. It is Iso known as air sac disease or chronic respira-jry disease. Those affected with the disease may how nasal discharge, watery eyes, and respira-)ry difficulty. This disease is often associated /ith other respiratory diseases. It is transmitted hiefly from infected hens to their chicks through le eggs. The disease can also be transmitted by ontact with infected individuals, but it spreads ery slowly in this manner. The disease can best e controlled by maintaining breeding flocks free f the disease by strict measures of isolation and mitation. Chicks hatched from such flocks can egin life free of the disease.
Such modified agents may be of three general kinds: (1) a living agent whose pathogenicity has been reduced or attenuated so that it no longer produces disease; (2) a killed preparation of the unaltered agent; and (3) a preparation of a product of the infectious agent. Similarly, in the broader, accepted sense, the term "vaccination" denotes the prophylactic inoculation of such materials in order to produce an effective active immunity to the corresponding disease.
|
|
|
 |
Child-Education-Usa.com |
|
 |
 |
|
Menu |
|
|
| |
| |
|
|
| |
|
