Typhoid fever is a life-threatening infection caused by the bacterium Salmonella Typhi. It is usually spread through contaminated food or water. Once Salmonella Typhi bacteria are ingested, they live only in humans. Persons with typhoid fever carry the bacteria in their bloodstream and intestinal tract. Typhoid fever is rare in places where few people carry the bacteria, and it is also rare where water is treated to kill germs and where human waste disposal is managed. Food and water with the bacteria in it cause typhoid fever, and close contact with a person who is carrying the salmonella bacteria can also cause typhoid fever.

Symptoms of typhoid fever include prolonged high fever, fatigue, headache, nausea, abdominal pain, and constipation or diarrhea. Some patients may have a rash. Severe cases may lead to serious complications or even death. Typhoid fever can be confirmed through blood testing.

Improved living conditions and the introduction of antibiotics resulted in a drastic reduction of typhoid fever morbidity and mortality in industrialized countries. However, the disease continues to be a public health problem in many developing areas of the world. As of 2019 estimates, there are 9 million cases of typhoid fever annually, resulting in about 110,000 deaths per year.

It is important for people being treated for typhoid fever to take prescribed antibiotics for as long as the doctor has prescribed, wash their hands with soap and water after using the bathroom, and avoid preparing or serving food for other people to lower the chance of passing the infection on to someone else. If you live in or travel to an area where typhoid is common, you should get vaccinated.