How are viral diseases classified ?

Explanation

Viral diseases are generally classified into four types on the basis of the symptoms produced in the body organs.
(i)Pneumotropic diseases (Eg: respiratory tract infected by influenza )
(ii)Dermotropic diseases (Eg: Skin and subcutaneous tissues affected by chicken pox and measles )
(iii)Viscerotropic diseases (Eg: blood and visceral organs affected by yellow fever and dengue fever )
(iv)Neurotropic diseases (Eg: central nervous system affected by rabies and polio ) .