Typhoid Fever

(Enteric Fever)

ByLarry M. Bush, MD, FACP, Charles E. Schmidt College of Medicine, Florida Atlantic University
Reviewed/Revised Jun 2024
VIEW PROFESSIONAL VERSION

Typhoid fever is caused by certain types of the gram-negative bacteria Salmonella. It typically causes a high fever and abdominal pain.

  • Typhoid fever can be spread by consuming food or water contaminated with the stool or urine of an infected person.

  • People have flu-like symptoms, sometimes followed by delirium, cough, exhaustion, occasionally rash, and diarrhea.

  • Samples of blood, stool, other body fluids, or tissues are sent to a laboratory to grow (culture) the bacteria.

  • Infected people with or without symptoms are treated with antibiotics.

  • To prevent infection, people traveling to areas where typhoid fever is common should be vaccinated and, when there, should avoid certain foods and not drink unbottled water.

(See also Overview of Bacteria and Salmonella Infections.)

Typhoid fever is one type of infection caused by Salmonella bacteria. There are many types of Salmonella, but most typhoid fever is caused by Salmonella Typhi.

Typhoid fever is common in areas where sanitary conditions are poor. In the United States, most cases of typhoid fever occur in travelers returning from parts of the world where typhoid fever is common. Worldwide, in 2019, an estimated 9.2 million people were diagnosed with typhoid fever and 110,000 people died. Most affected people lived in regions in Southeast Asia, the Eastern Mediterranean, and Africa.

Did You Know...

  • Mary Mallon, so-called Typhoid Mary, was a cook who spread typhoid fever to many people during the early 20th century.

Transmission

Salmonella Typhi is present only in people.

People who are infected excrete the bacteria in stool and, rarely, in urine. A few infected people develop chronic infection of the gallbladder or urinary tract. They continue to excrete the bacteria in stool or urine, even though they no longer have any symptoms. Such people are called carriers. Thus, they do not know they can spread the infection. During the early 20th century, one such woman, a cook named Mary Mallon, spread typhoid fever to many people and became known as Typhoid Mary.

Salmonella Typhi bacteria may contaminate food or drink when hands are inadequately washed after defecation or urination. Water supplies may be contaminated when sewage is inadequately treated. Flies may spread the bacteria directly from stool to food.

Occasionally, typhoid fever is spread by direct contact between children during play or between adults during anal-oral sex.

Like all Salmonella bacteria, many of these bacteria must be consumed for infection to develop. Because stomach acid tends to destroy Salmonella bacteria, people who have low stomach acid, such as older adults and people who take acid-suppressing medications, have an increased risk of infection. People who take antibiotics are also at increased risk because antibiotics can disrupt the resident flora in the digestive tract that protects the body against disease-causing organisms.

Spread through the bloodstream

The bacteria spread from the digestive tract to the bloodstream (causing bacteremia) and may infect distant organs such as the following:

These infections develop mainly when people are not treated or when treatment is delayed.

Symptoms of Typhoid Fever

Typically, a flu-like illness begins about 8 to 14 days after infection. Typhoid fever symptoms begin gradually. People may have a fever, headache, sore throat, muscle and joint pains, abdominal pains, and a dry cough. They may lose their appetite.

After a few days, the temperature peaks at about 103 to 104° F (39 to 40° C), remains high for another 10 to 14 days, and returns to normal during the fourth week after symptoms started. Often the heartbeat is slow, and people feel exhausted. When the infection is severe, they may become delirious or comatose.

During the second week, a rash of flat, rose-colored spots develops on the chest and abdomen in about 5 to 30% of people.

Typhoid Fever (Rose Spots)
Hide Details
In about 5 to 30% of people with typhoid fever, rose-colored spots (arrows) appear on the chest and abdomen, usually during the second week of infection.
Image courtesy of Charles N. Farmer, Armed Forces Institute of Pathology, via the Public Health Image Library of the Centers for Disease Control and Prevention.

People may be constipated at first, but after 2 weeks, diarrhea may occur. In about 1 to 2% of people, the intestine is torn (perforated) or bleeds. A few people have severe, sometimes life-threatening bleeding.

If infection spreads to other organs, symptoms of those infections may also develop.

In up to 10% of untreated people, symptoms return about 2 weeks after the fever goes away.

Diagnosis of Typhoid Fever

  • Examination and culture of samples of blood, stool, or other body fluids or tissues

To confirm the diagnosis of typhoid fever, doctors take samples of blood, stool, urine, and sometimes other body fluids or tissues and send them to a laboratory where the bacteria, if present, can be grown (cultured). The samples are examined and tested to determine whether Salmonella bacteria are present.

Lab Test

Tests to determine which antibiotics are likely to be effective (susceptibility tests) are also done.

Treatment of Typhoid Fever

  • Antibiotics

  • For severe infections, corticosteroids

Doctors typically give one of the following antibiotics:

Resistance to antibiotics is common and is increasing in areas where typhoid fever is common. Resistance is also increasing in the United States because of returning travelers who were infected in those areas.

If the infection is severe, corticosteroids are also given by injection, particularly when people are delirious, comatose, or in shock.

While people have a fever, bed rest is advised. A clear liquid diet can help minimize diarrhea. People should not use aspirin, laxatives, or enemas.

Relapses can occur after treatment is stopped. This infection is milder than the initial illness but is treated the same way.

Treatment of carriers

Identified carriers are reported by health care professionals to the local health department. The local health department then reaches out to carriers and takes measures to prevent further spread.

Carriers are not allowed to work with food until tests show that the bacteria have been eradicated. Taking antibiotics for 4 to 6 weeks may eradicate the bacteria in many carriers.

If carriers have gallbladder disease, surgery to remove the gallbladder may be effective. However, such surgery does not guarantee that the bacteria are eradicated.

Prognosis for Typhoid Fever

Without treatment, typhoid fever is fatal in about 10 to 15% of people. With treatment, typhoid fever is fatal in only about 1% of people. Most deaths occur in people who are malnourished, very young, or very old.

Complete recovery may take weeks or months.

Stupor (unresponsiveness that requires vigorous stimulation to be aroused), coma, and shock are signs of severe infection and a poor prognosis.

Prevention of Typhoid Fever

People who travel to areas where typhoid fever is common should avoid eating raw vegetables and other foods served or stored at room temperature.

People should assume that ice and water (unless it is boiled or chlorinated before use) are unsafe. Sealed bottled water should be used for brushing teeth.

Generally, people can safely consume the following:

  • Foods that are served very hot immediately after cooking

  • Bottled or canned beverages that are sealed

  • Hot tea or coffee

  • Fruit that they have peeled themselves

Vaccination

A typhoid vaccine given by mouth (orally) and a polysaccharide vaccine given by injection into a muscle can help prevent typhoid fever. The oral vaccine is about 40 to 80% effective. It can be given to people 6 years old and older. The injected vaccine is about 50 to 80% effective. It can be given to people 2 years old and older. Both vaccines have few side effects.

Vaccination is recommended for

  • Travelers to regions where typhoid fever is common

  • People who live in a household with or who have close contact with carriers

  • Laboratory workers who work with the bacteria

People who remain at risk should receive a booster vaccine 2 years after receiving the injected vaccine and 5 years after receiving the oral vaccine.

More Information

The following English-language resource may be useful. Please note that THE MANUAL is not responsible for the content of this resource.

Centers for Disease Control and Prevention (CDC): Typhoid Fever: A resource providing information about typhoid fever, including information for travelers

Drugs Mentioned In This Article
quizzes_lightbulb_red
Test your KnowledgeTake a Quiz!
Download the free Merck Manual App iOS ANDROID
Download the free Merck Manual App iOS ANDROID
Download the free Merck Manual App iOS ANDROID