Typhoid fever is caused by a virulent bacterium called Salmonella typhi. Although they're related, S. typhi and the bacterium responsible for salmonellosis, another serious intestinal infection, aren't the same.
Fecal-oral transmission route
The bacteria that cause typhoid fever spread through contaminated food or water and occasionally through direct contact with someone who is infected. In developing nations, where typhoid is endemic, most cases result from contaminated drinking water and poor sanitation. The majority of people in industrialized countries pick up the typhoid bacteria while traveling and spread it to others through the fecal-oral route.
This means that S. typhi is passed in the feces and sometimes in the urine of infected people. You can contract the infection if you eat food handled by someone with typhoid fever who hasn't washed carefully after using the toilet. You can also become infected by drinking water contaminated with the bacteria.
Even after treatment with antibiotics, a small number of people who recover from typhoid fever continue to harbor the bacteria in their intestinal tracts or gallbladders, often for years. These people, called chronic carriers, shed the bacteria in their feces and are capable of infecting others, although they no longer have signs or symptoms of the disease themselves.
Aug. 22, 2012
- Brunette GW, et al. CDC Health Information for International Travel 2012. Atlanta, Ga.: U.S. Department of Health and Human Services, Public Health Service; 2012. http://wwwnc.cdc.gov/travel/yellowbook/2010/chapter-2/typhoid-paratyphoid-fever.aspx. Accessed April 26, 2012.
- Typhoid fever. Centers for Disease Control and Prevention. http://www.cdc.gov/nczved/divisions/dfbmd/diseases/typhoid_fever/. Accessed April 18, 2012.
- Maurice J. A first step in bringing typhoid fever out of the closet. The Lancet. 2012;379:699.
- Goldman L, et al. Cecil Medicine. 24th ed. Philadelphia, Pa.: Saunders Elsevier; 2008. http://www.mdconsult.com/books/page.do?eid=4-u1.0-B978-1-4377-1604-7..00316-X&isbn=978-1-4377-1604-7&sid=1301718288&uniqId=331385541-5#4-u1.0-B978-1-4377-1604-7..00316-X. Accessed April 26, 2012.
- Bope ET, et al. Conn's Current Therapy. Philadelphia, Pa.: Saunders Elsevier; 2012. http://www.mdconsult.com/books/linkTo?type=bookHome&eid=4-u1.0-B978-1-4557-0738-6..C2009-0-38985-0--TOP&isbn=978-1-4557-0738-6&uniqId=331385541-3. Accessed April 26, 2012.
- Mayer CA, et al. Typhoid and paratyphoid fever. Australian Family Physician. 2010;39:847.
- Crump JA, et al. Global trends in typhoid and paratyphoid fever. Clinical Infectious Diseases. 2010;50:241.
- Humphries RL, et al. Current Diagnosis & Treatment Emergency Medicine. 7th ed. New York, N.Y.: The McGraw-Hill Companies; 2011. http://www.accessmedicine.com/content.aspx?aID=55748503. Accessed April 27, 2012.
- Longo DL, et al. Harrison's Online. 18th ed. New York, N.Y.: The McGraw-Hill Companies; 2012. http://www.accessmedicine.com/content.aspx?aID=9113180. Accessed April 27, 2012.