Questions and Answers

What are typhoid fever and paratyphoid fever?

Typhoid fever is a life-threatening illness caused by Salmonella Typhi bacteria. Paratyphoid fever is a life-threatening illness caused by Salmonella Paratyphi bacteria.

How many people get typhoid fever and paratyphoid fever each year?

Worldwide, typhoid fever affects an estimated 11 to 21 million people and paratyphoid fever affects an estimated 5 million people each year.

In the United States each year, about 350 people are diagnosed with typhoid fever and 90 people are diagnosed with paratyphoid fever each year. 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. CDC estimates typhoid fever affects 5,700 people in the United States each year. CDC has not made estimates for Salmonella Paratyphi.

Most people diagnosed in the United States have traveled to places where the diseases are most common.

Where are the diseases most common?

Typhoid fever and paratyphoid fever are most common in parts of the world where water and food may be unsafe and sanitation is poor. Travelers to South Asia, especially Pakistan, India, and Bangladesh, should take precautions to prevent infection. Typhoid fever and paratyphoid fever are somewhat less common in East Asia, Africa, the Caribbean, and Central and South America. Both diseases are rare in the United States, Canada, Western Europe, Australia, or Japan.

How are typhoid fever and paratyphoid fever spread?

These diseases are spread through sewage contamination of food or water and through person-to-person contact. People who are currently ill and people who have recovered but are still passing the bacteria in their poop (stools) can spread Salmonella Typhi or Salmonella Paratyphi.

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 (getting rid of) Salmonella Typhi or Salmonella Paratyphi in their poop 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.

What happens if you eat or drink something contaminated with Salmonella Typhi or Salmonella Paratyphi?

If you consume a food or drink contaminated with Salmonella Typhi or Salmonella Paratyphi, the bacteria can multiply and spread into the bloodstream, causing typhoid fever or paratyphoid fever.

How can I protect myself from typhoid fever and paratyphoid fever?

If you are planning to travel outside the Uni ted States, you should do the following:

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 poop, or places where animals live, feed, or roam. Get more tips >