There are many diseases caused by viruses.Following are most common in Pakistan:
Small pox is caused by pox virus.Pox virus is DNA enveloped virus.Small pox is an ancient disease that occurred as an epidemic in China in twelfth century.Immunization and vaccination decrease this but still it is present in some areas of the world.
- Fluid filled vesicles are formed on the body.
- then they are changed into pitted scars known as pocks.
Herpes virus is DNA virus.It is naturally occurring disease.Vascular lesions in the epithelial layer of ectodermal tissues are formed.Most commonly it occurs on lips,mouth and skin sites.
They are enveloped RNA virus that cause infleunza.It is common in man and occur in epidemic forms.
Poliomyelitis is caused by polio virus.It is found all over the world.This disease occur in childhood.The polio virus are the smallest known virus.The age at which infection depends on social and economic factors.
Mumps and measles:
The group of measles and mumps is known as para myxoviruses.Mumps is highly contagious,wide spread but seldom fatal.In this,fluid filled vesicles are formed on the body.About 60% adults are immune to it.Measles is one of the most common disease in young children.It develops immunity in its victim.