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 (sneezes, cough) and saliva drops are: bacterial pneumonias, tuberculosis, whooping cough (pertussis), diphtheria, bacterial meningitis. Major bacterial diseases transmitted by blood or sexual contact are: gonorrhea, syphilis. Main bacterial diseases transmitted by animal vectors are: bubonic plague, endemic typhus, leptospirosis. Some bacterial diseases transmitted by fecal-oral route and contaminated food are: cholera, typhoid fever. Other significant bacterial infections: Hansen's disease, possibly transmitted by saliva drops and contact with injured skin and mucosae; trachoma, eye disease transmitted by ocular secretions; tetanus, transmitted when the etiological agent enters the body by skin wounds.