Key points
- Typhoid fever and paratyphoid fever are life-threatening illnesses.
- Each of the illnesses is caused by a kind of Salmonella bacteria (germs).
- Most people in the United States with these illnesses were infected during international travel.
- You can find out if you need a typhoid fever vaccine at www.cdc.gov/travel.
Overview
Symptoms
Typhoid fever and paratyphoid fever have similar symptoms, including fever. The illnesses are life-threatening and people with symptoms should get medical help immediately.
Germs responsible
The illnesses are caused by Salmonella bacteria.
- Typhoid fever is caused by Salmonella serotype Typhi.
- Paratyphoid fever is caused by Salmonella serotype Paratyphi.
Illness estimates
Every year, millions of people around the world get sick from these diseases.
Typhoid fever
- 9.2 million illnesses are estimated to occur worldwide each year
- 5,700 illnesses and 620 hospitalizations are estimated to occur in the United States each year. Most people are infected while traveling internationally.
Paratyphoid fever
- 3.8 million illnesses are estimated to occur worldwide each year
- CDC does not have estimates of illnesses and hospitalizations in the United States
Where illness is common
These illnesses are most common in parts of the world where water and food can be unsafe, and sanitation can be poor, including parts of:
- Asia (especially Pakistan, India, and Bangladesh)
- Africa
- Latin America
Most people in the United States with typhoid fever or paratyphoid fever were infected while traveling to these places.
Risk factors
The chances of getting typhoid fever or paratyphoid fever in the United States are very low.
The chances increase for people in the United States who:
- Travel to countries in Africa, Asia, or Latin America where the diseases are common
- Visit rural areas of those countries
- Visit family and friends in those countries
- Are not vaccinated against typhoid fever
Almost all people in the United States with these diseases report that they have traveled internationally. Most report that they traveled to countries in South Asia, including Pakistan, India, or Bangladesh.
How it spreads
The bacteria spread to and among people in several ways
The bacteria that cause these illnesses are shed (gotten rid of) in poop. People who shed the bacteria include:
- People who have symptoms of typhoid fever or paratyphoid fever
- People who are no longer sick but still have the bacteria in their body
You can get typhoid fever or paratyphoid fever after swallowing the bacteria. The bacteria can get in your mouth in several ways, including:
- Through food, drinks, and water that have been contaminated by sewage
- Through food that has been rinsed in contaminated water and then eaten
- Through food that has been touched by a person who did not wash their hands after using the bathroom or changing a diaper