1. Causing human diseases: Viruses cause serious diseases like human measles, measles, polio, rabies, influenza, jaundice, herpes, dengue, hepatitis, Ebola, AIDS, Sars, swine flu, cancer etc. Viruses that cause cancer in the human body are called oncogenic viruses. Cancer-causing DNA viruses are called simian and RNA viruses are called retroviruses. Human papillary virus (HPV) causes tumors, Kaposi sarcoma herpes virus (KSHV) causes skin cancer and hepatitis-C virus causes liver cirrhosis.
2. Plant Diseases: Diseases like plant mosaic, leafroll, tomato bushist, rice tungro, papaya ring spot, banana bunchy top etc. are caused by viruses. About 300 plant diseases are caused by viruses and reduce yields. Dr. Siddiq Publications
3. Cattle Diseases: Bovine Spring Disease; Foot and mouth disease in cattle, buffalo, sheep, goats, pigs, etc. and rabies in dogs and cats are caused by viruses.
4. Poultry Diseases: Poultry diseases such as avian, influenza, bird flu, swine flu etc. are caused by viruses.
5. Silkworm disease: Nuclear polyhedrosis virus (NPV) causes silkworm disease. This resulted in a disaster in the silk industry.