Questions and Answers

What is typhoid fever?

Typhoid fever is a life-threatening illness caused by the bacterium Salmonella Typhi. Typhoid fever is not common in the United States, Canada, Western Europe, Australia, or Japan, but it is common in many other countries. It affects an estimated 22 million people worldwide each year. In the United States, about 350 people are diagnosed with typhoid fever each year, most often after traveling outside of the United States to countries such as India, Bangladesh, and Pakistan. These cases do not include people who do not seek medical care, who are not tested for either disease, or whose disease is not reported to CDC.

What is paratyphoid fever?

Paratyphoid fever is a life-threatening illness caused by the bacterium Salmonella Paratyphi. Paratyphoid fever is not common in the United States, Canada, Western Europe, Australia, or Japan, but it is common in many other countries. It affects an estimated 5 million people worldwide each year. In the United States, about 90 people are diagnosed with paratyphoid fever each year, most often after traveling outside of the United States. These cases also do not include people who do not seek medical care, who are not tested for either disease, or whose disease is not reported to CDC.

How are typhoid fever and paratyphoid fever spread?

People who are actively ill with typhoid fever or paratyphoid fever and people who are carriers of Salmonella Typhi or Salmonella Paratyphi bacteria can both spread the bacteria to other people. Carriers are people who have recovered from typhoid fever or paratyphoid fever but continue to carry the bacteria. About 1 in 20 people remain carriers after they’ve recovered. Both groups of people shed (excrete) Salmonella Typhi or Salmonella Paratyphi in their feces (poop).

Typhoid fever and paratyphoid fever are more common in areas of the world where water is more likely to be contaminated with sewage.

You can get typhoid fever or paratyphoid fever if

  • You eat food or drink a beverage that has been touched by a person who is shedding Salmonella Typhi or Salmonella Paratyphi and who has not washed their hands thoroughly after going to the bathroom.
  • Sewage contaminated with Salmonella Typhi or Salmonella Paratyphi gets into water you drink.
  • Sewage contaminated with Salmonella Typhi or Salmonella Paratyphi gets into water used to rinse food you eat raw.

Can typhoid fever and paratyphoid fever be prevented?

Yes. Typhoid fever and paratyphoid fever can be prevented. If you are planning to travel outside the United States, you should

Can animals spread typhoid fever or paratyphoid fever to people?

No. Salmonella Typhi and Salmonella Paratyphi live only in humans.

Animals can spread other kinds of Salmonella to humans, so it’s important to wash your hands after contact with animals, their feces (poop), or places where animals live, feed, or roam. Learn more >

What happens when someone ingests Salmonella Typhi or Paratyphi?

When someone consumes a food or drink contaminated with Salmonella Typhi or Paratyphi, the bacteria can multiply and spread into the bloodstream, causing typhoid fever or paratyphoid fever.