Typhoid fever is a serious infection caused by the bacterium Salmonella enterica serotype Typhi, commonly called Salmonella Typhi. It is usually spread through contaminated food or water and affects the intestines and bloodstream. Symptoms typically begin gradually 6 to 30 days after exposure and include a high fever, weakness, abdominal pain, headache, constipation or diarrhea, and sometimes a characteristic skin rash with rose-colored spots. Without treatment, symptoms can persist for weeks or months and may lead to severe complications. Typhoid fever is contagious and can be spread through fecal contamination of food and water by infected individuals. It primarily affects humans and is more common in areas with poor sanitation and limited access to clean water. Antibiotics are used to treat the infection, and vaccines are available for prevention.