Salmonella typhi or S. paratyphi.

The disease was initially called typhoid fever because of its clinical similarity to typhus. In the early 1800s, typhoid fever was clearly defined pathologically as a unique illness on the basis of its association with enlarged Peyer’s patches and mesenteric lymph nodes.

Typhoid fever is highly contagious. An infected person can pass the bacteria out of their body in their poo (stools) or, less commonly, in their pee (urine).

If someone else eats food or drinks water that's been contaminated with a small amount of infected poo or urine, they can become infected with the bacteria and develop typhoid fever.

 S. enterica serovar Typhi, the etiologic agent of typhoid fever, produces a pilus protein that binds to CFTR to enter the gastrointestinal submucosa after being ingested by enterocytes. As homozygous mutations in CFTR are the cause of the life-shortening disease cystic fibrosis, heterozygote carriers (e.g., 4–5% of individuals of European ancestry) may have had a selective advantage due to decreased susceptibility to typhoid fever.

Typhoid fever is spread through food and water contaminated by animal and human feces. Typhoid fever is very rare in the United States and other developed nations, and it is more common in underdeveloped nations, particularly Latin America, Asia, and Africa.

When traveling to underdeveloped areas, a good way to remember what foods and beverages are safe is to think of the following: If you cannot boil it (to kill bacteria), peel it (to remove bacteria) or cook it (to kill bacteria), do not eat it.

When traveling to areas without clean drinking water, also remember to avoid ice cubes, which may be made with contaminated water, and to check the seal on all bottled water that you purchase (as the water bottle may have been refilled with unclean water). Some travelers drink only carbonated water in order to avoid this issue.





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