Q. What are some human diseases caused by bacteria and what are their respective modes of transmission?
The major human bacterial infections transmitted by respiratory secretions (cough, sneezes) and saliva drops are tuberculosis, bacterial pneumonias, whooping cough (pertussis), diphtheria, bacterial meningitis. Major bacterial diseases transmitted by blood or sexual contact are gonorrhea, syphilis. Major bacterial diseases transmitted by animal vectors are endemic typhus, bubonic plague, leptospirosis. Various bacterial diseases transmitted through fecal-oral route and contaminated foods are typhoid fever, cholera and other important bacterial infections: Hansen's disease, possibly transmitted by saliva drops and contact with injured mucosae and skin, trachoma, eye disease transmitted by ocular secretions, tetanus, transmitted when the etiological agent enters the body through skin wounds.