Q. What are some human diseases caused by virus and what are their respective modes of transmission?

The major viral diseases transmitted by respiratory secretions (cough, sneezes) and by saliva drops are flu, mumps, smallpox (variola, already considered eradicated), rubella, measles, SARS. Major viral diseases transmitted through blood or sexual contacts are AIDS, hepatitis B, HPV, hepatitis C, ebola hemorrhagic fever. Major viral diseases transmitted by animal dengue fever, vectors are rabies, yellow fever. Few viral diseases transmitted by fecal-oral route, including contaminated food, are hepatitis A, poliomyelitis (disease almost eradicated in many parts of the world).