 |
 |
|
|
|
|
|
|
|
Rare Disease: Thus, this kind of heart disease has been practically eradicated, although rare disease cases are still encountered in elderly people. Other endocrine disorders affecting the heart are very rare disease.
Congenital Heart Disease. With the increasing control of rheumatic heart disease it is probable that congenital cardiovascular disease will soon outstrip it in incidence, and with the increasing control of high blood pressure, congenital heart disease will take second place. An interesting statistical fact is that in the 1920's, T. Duckett Jones and Paul Dudley White found that congenital heart disease made up only 1.5% of all of 3,000 patients with Signs or symptoms of heart disease.
Although most of the causes of heart disease observed in the first quarter of the 20th century are still present, their relative proportions have changed considerably, and some causes that were mentioned only occasionally or not at all at that time are considered common today. This is especially true of the virus infections. In some parts of the world the diagnosis of "heart disease of unknown origin" is a common one. In the United States such a diagnosis exists but is uncommon, and a few kinds of heart disease that are common in certain other countries are rare disease or nonexistent in the United States. For example, Chagas' disease (myocardial trypanosomiasis) is a parasitic infestation of the heart common in South America.
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.
|
|
|
|
