What Is Typhoid?
Typhoid , or typhoid fever, is a very serious and potentially fatal illness caused by the bacterium Salmonella typhi.
Typhoid can be prevented by a vaccine. Although the typhoid vaccine is effective, it cannot prevent 100% of typhoid infections.
Typhoid fever does occur within the US; however, it is far more prevalent in developing countries where water is likely to be contaminated by bacteria. So it is important, particularly when traveling in Asia, Africa, and Latin America, to be aware of possible bacteria contamination of food and water.
S. typhi is contracted through drinking water that has been contaminated with sewage. It can also be ingested by eating food that has been washed in bacteria-laden water.
The most common symptoms of typhoid include:
- High fever, usually up to 103˚F or 104˚F
- Weakness
- Fatigue
- Stomach pains
- Loss of appetite
- Headache
Fever in patients with typhoid is usually persistent. Many patients also exhibit a rash.
Typhoid is treated with antibiotics. Without treatment, fever and symptoms may continue for weeks or months, and death may occur as a result of complications from the bacterial infection.
What Is the Typhoid Vaccine?
There are two types of typhoid vaccines:
- An inactivated (killed) vaccine that is injected
- A live, attenuated (weakened) vaccine administered orally
The inactivated vaccine is given as a shot and should not be given to children younger than two years old. A single dose should be given at least 14 days before traveling abroad. Booster shots are needed every two years for those who continue to be in parts of the world where they would be exposed to typhoid fever.
The live typhoid vaccine is administered orally and should not be given to children younger than six years old. Four doses, with a day separating each dose, are needed. A booster dose is needed every five years.
Who Should Get Vaccinated and When?
Although the typhoid vaccine is not administered routinely in the US, the following individuals should be vaccinated:
- People who are traveling to areas outside the US where typhoid commonly exists
- People who are in close contact with an individual who has or carries typhoid
- People who work with S. typhi , typically laboratory workers
Boosters of the inactive vaccine are required every two years for people at risk for contracting typhoid, and every five years for those at risk who take the oral vaccine.
For maximum effectiveness, the vaccine should be taken 2-3 weeks prior to the potential exposure to S. typhi .
What Are the Risks Associated With the Typhoid Vaccine?
Common side effects include:
- Fever
- Headache
- Redness or swelling at injection site (inactivated only)
Less common side effects include:
- Abdominal pain
- Nausea or vomiting
- Rash
Side effects that may indicate a serious allergic reaction include:
- Changes in behavior
- Extremely high fever
- Difficulty breathing, hoarse voice, or wheezing
- Hives
- Pale skin
- Weakness
- Rapid heartbeat
- Dizziness
Who Should Not Get Vaccinated?
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For the shot, the following individuals should not get vaccinated. Those who:
- Have had a severe allergic reaction to a previous typhoid vaccine or any of its components
- Are under age 2 years
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For the oral vaccine, the following individuals should not get vaccinated. Those who:
- Have had a severe allergic reaction to a previous typhoid vaccine or its components
- Are under age 6 years
- Are currently taking certain antibiotics
- Have a weakened immune systems, including HIV/AIDS
- Are being treated with drugs that can compromise the immune system, such as steroids
- Have cancer
- Are undergoing treatment for cancer with medicine or radiation
Consult your doctor if you are traveling and are at risk for acquiring typhoid fever, especially if you have any of the above conditions.
What Other Ways Can Typhoid Be Prevented Besides Vaccination?
Below are some ways to decrease your risk of getting typhoid:
- Frequent and thorough hand washing, particularly before handling food
- Properly cleaning and preparing food to ensure no contamination
- Not eating uncooked vegetables or fruit that cannot be peeled
- Boiling water before drinking or using
- Avoiding potentially contaminated food or water
What Happens in the Event of an Outbreak?
If the suspected cause comes from a commercial food-service facility, the facility and employees should be investigated within 24 hours of determining the suspected source.
If the suspected source is a daycare facility, the facility and employees should be investigated and questioned about recent travel and symptoms.
Also, in the event of an outbreak, government agencies should educate the public on ways to prevent the transmission of typhoid, including proper hygiene habits and careful food preparation.
Revision Information
- Reviewer: Lawrence Frisch, MD, MPH
- Review Date: 12/2011 -
- Update Date: 12/30/2011 -