The virus is a very tiny microbe that can be seen only under an electron microscope. It replicates rapidly inside the host cell employing hosts enzymes and organelles for its multiplication.
Viral diseases are known for the serious effects of their epidemics. There are many types of viral diseases. To mention a few, Dengue, Influenza, Swine flu, Bird flu, Sars, Encephalitis, etc. reach epidemic proportions and affect a large number of people all over the world leading to high morbidity and mortality.
Epidemic diseases like Chikungunya, Poliomyelitis, Conjunctivitis are known for their severe morbidity. Measles, Chickenpox is also epidemic but less harmful
Hepatitis B, Hepatitis C is contagious but not epidemic. They are lingering, incurable chronic diseases affecting important organs like the liver and sometimes leading to many complications and ultimately death.
There are many viral diseases that affect domestic animals in the form of viral epidemics, leading to a lot of morbidity and mortality, causing great financial loss to society and countries.
What is their significance ?
The development of antiviral compounds for chemotherapy and chemoprophylaxis of viral diseases is a difficult task because of the peculiar biologic properties of viruses. Hence there is no satisfactory and dependable chemotherapy for many viral diseases.
What is the status of currently available treatment for viral diseases?
Presently, there is no satisfactory treatment for many viral diseases in any recognized system of medicine. One has to helplessly depend on the less useful symptomatic and supportive treatment only, waiting for the final verdict of nature.
However, preventive vaccination is available against a few viral diseases. Viruses have a natural tendency to mutate rapidly. This makes attempts to prepare an effective and lasting vaccine difficult.