Typhoid fever is a potentially life-threatening bacterial illness that occurs when people consume foods or fluids contaminated with the bacteria Salmonella typhi. The bacteria quickly multiply in the body and spread from the intestines to the bloodstream. They may affect the liver, lymph nodes, spleen and gallbladder.

The incidence of typhoid fever has been dramatically reduced in industrialized nations due to improved sanitation. However, typhoid fever remains common in developing countries. People who travel to developing areas of the world are at an increased risk of infection. People living in communities with poor sanitation, or among people who practice poor hygiene (e.g., not washing hands after defecation or urination) are also at an increased risk of contracting a variety of infectious diseases, including typhoid fever.

Fever is the primary symptom associated with typhoid fever. A sustained fever typically runs as high as 103 to 104 degrees Fahrenheit (39 to 40 degrees Celsius). Some patients also develop distinctive rose spots on their chest or abdomen. Additional symptoms include headaches, loss of appetite and weakness. As the illness progresses, it may cause more severe symptoms, including delirium and hallucinations. Left untreated, typhoid fever can be fatal.

Blood or stool tests are typically used to identify the presence of Salmonella typhi bacteria. These tests may be performed after treatment to ensure no Salmonella typhi bacteria remain in the body. Antibiotics are typically used to treat typhoid fever.

People who travel to developing areas are urged to take precautions to prevent infection. This includes vaccination against typhoid fever. In addition, potentially contaminated foods and beverages should be avoided while traveling.

Typhoid fever is a potentially life-threatening bacterial infection. People become infected after consuming foods or fluids contaminated with the bacteria Salmonella typhi. About 400 cases of typhoid fever are diagnosed in the United States each year, and most of these (75 percent) are acquired in developing countries, according to the U.S. Centers for Disease Control and Prevention (CDC).

After a person ingests Salmonella typhi, the bacteria quickly multiply and spread from the intestine to the bloodstream. From there, the bacteria may travel to and affect the liver, lymph nodes and spleen. Salmonella typhi may also directly infect the gallbladder or spread to other areas of the body. Symptoms such as fever, fatigue and abdominal pain usually appear within two or three weeks after exposure to the bacteria. Certain complications also may occur as a result of typhoid fever. These include intestinal hemorrhage, intestinal perforation, kidney failure and inflammation of the lining inside the abdomen (peritonitis).

Salmonella typhi bacteria live only in humans and sometimes continue to live on in people even after they are treated and recover from infection. Such people are said to be carriers of typhoid fever. About 5 percent of people who contract the illness become carriers. The most famous case of a typhoid carrier was a woman known as Typhoid Mary, who lived in New York in the early 1900s. Although never apparently ill with typhoid fever, she worked as a cook and spread the disease through the food she prepared. Local health authorities confined her several times and attempted to prevent her from working as a cook.

Carriers as well as people actively infected with typhoid fever shed the bacteria in their stool. Occasionally, bacteria may also be present in the urine. Healthy people can become infected after consuming food or beverages handled by a person who is shedding the bacteria (e.g., if that person’s hands are not thoroughly washed after coming into contact with feces). Sewage containing Salmonella typhi may also contaminate water used for drinking or washing food.

Typhoid was previously a common infection in the United States, but its incidence has dramatically declined in industrialized countries due to improved sanitation (e.g., public sewage systems). There is little risk of contracting the infection in areas of the world such as the United States, Canada, Australia, Japan, New Zealand and western Europe. However, typhoid fever remains common in developing nations. People who travel to areas such as India, Africa, Central and South America, Asia and the Caribbean have an increased risk of contracting the infection. In these regions, an estimated 22 million infections and 200,000 related deaths occur worldwide every year, according to the CDC.

Typhoid fever is caused by the bacteria Salmonella typhi. The most common risk factor for contracting typhoid fever is exposure to the bacteria, usually in areas of poor sanitation. Travel to such areas, including most developing countries, can increase the risk of contracting typhoid fever.

People infected with or carrying typhoid shed the bacteria in their feces. From there, it can contaminate water supplies in areas with little or no management of water facilities. It may also spread directly if an infected person does not wash after defecating or urinating, or before preparing food. Eating or drinking in such an environment also increases the risk of typhoid infection.

In diagnosing typhoid fever, a physician will perform a complete physical examination and compile a thorough medical history. A physician may ask about recent travel or whether the patient has lived in or visited areas with poor sanitation.

The only way to be sure that a patient has typhoid fever is to test blood or stool samples for the presence of Salmonella typhi bacteria. Blood tests may also be performed that check for an altered white blood cell count and platelet count. These results may indicate the presence of an infection, although not necessarily Salmonella typhi infection.

Certain blood tests may be better able to identify the Salmonella typhi bacteria during the early stages of infection (e.g., first week of the fever) than stool tests. However, as the infection progresses and bacteria begin to be shed from the body, stool tests may be preferred over blood tests. In some cases, a urine test may be performed to check for the passage of bacteria in the patient’s urine. Analysis of a sample of the patient’s bone marrow is the most sensitive diagnostic test for Salmonella typhi, although these samples are more difficult to obtain.

Antibiotics are typically used to treat typhoid fever. In most cases, patients begin to feel better within two to three days of taking these medications, and the illness usually completely resolves within a month. However, relapse of the initial infection may occur if treatment does not completely rid the body of infection. In addition, the effectiveness of treatment may depend on when medications are first administered (e.g., complete recovery is expected if drugs are begun before complications develop).

It is important that all patients take all prescribed medications to ensure the bacteria has been eliminated from the body. Physicians should carefully choose an antibiotic because some bacteria have developed antibiotic resistance in recent years. The Salmonella typhi bacteria have become resistant in recent years to certain antibiotics.

Some patients may also receive intravenous fluids and electrolytes when they are dehydrated as a result of prolonged fever and diarrhea associated with typhoid fever.

Even when medications are completed as recommended, some people may continue to carry the bacteria in their bodies (and shed them in their stool) for years. This may occur even after symptoms have resolved and treatment has been completed. Identifying carriers can be difficult. Anyone suspected of continuing to harbor the bacteria after an initial infection should consult their physician about follow-up diagnostic tests. In these cases, blood or stool tests may  identify the presence of Salmonella typhi bacteria that remain in carriers.

Carriers may be treated with additional antibiotics. These may be taken for a longer period of time, or a different types of drugs may be prescribed. In most carriers, the bacteria that cause typhoid fever are harbored in the gallbladder. In some cases, the bacteria may survive there, despite antibiotic treatment. Surgery to remove the gallbladder may be necessary to remove the bacteria from the body.

People who are carriers of typhoid fever may exhibit no signs of illness, but may continue to shed the bacteria in their stool. These carriers can continue to spread typhoid fever to others. Thus, in some cases, a physician may retest a person’s blood or stool for evidence of Salmonella typhi bacteria after treatment has concluded.

People in industrialized nations are at a low risk of contracting typhoid fever. However, anyone who travels to developing nations are urged to take precautions to prevent infection with Salmonella typhi. Areas with the highest risk of typhoid fever include parts of India, Africa, Central and South America, Asia and the Caribbean. 

Some travelers may be tempted to use antibiotics as a preventive measure. However, this is not effective. While antibiotics may be used to treat an infection, they will not prevent a person from contracting the infection.

Although not required for international travel, vaccination against typhoid fever is available. The U.S. Centers for Disease Control and Prevention (CDC) recommends this vaccination when traveling to high-risk areas of the world.

To be effective, the vaccine must be administered at least one week before the person travels. Typhoid fever vaccines are only good for several years, after which they lose their effectiveness. In addition, there are minimum age restrictions for these vaccines. Boosters may be necessary every two or five years, depending on the type of vaccine received (e.g., capsule or injection). People who travel to developing nations are urged to consult their physician about vaccination options. No vaccine exists for paratyphoid fever.

However, vaccinations may not be 100 percent effective. It is important while traveling in high-risk areas to avoid consuming foods and beverages that may be contamination. Travelers are urged to drink only bottled water while visiting developing countries. If the choice is available, bottled water that is carbonated is safer to consume than noncarbonated bottled water. If bottled water is not available, bringing water to a rolling boil for at least one minute before drinking is advised. Drinks with ice (including shaved or flavored ices) and popsicles should be avoided.

Travelers are also urged to avoid raw vegetables and fruits that cannot be peeled. These items should be personally peeled, rather than relying on food service staff or restaurant kitchens to peel the items. For example, vegetables such as the lettuce are easily contaminated. All foods should be thoroughly cooked so that they are hot and steaming, and foods and beverages from street vendors should be avoided.

Practicing good hygiene is one of the best methods for preventing many different types of infectious diseases, including typhoid fever. Frequent handwashing, especially after bowel movements or urination can help prevent the spread of infection. Keeping personal items (e.g., utensils, beverage containers, towels and bed linens) separate may also prevent the spread of infection. It also is important for communities to take steps to prevent to ensure adequate water treatment and waste disposal methods are used to prevent sewage from contaminating water supplies.

Preparing questions in advance can help patients have more meaningful discussions with healthcare professionals regarding their conditions. Patients may wish to ask their doctor the following questions related to typhoid fever:

1. What signs should I look for that might indicate I have typhoid fever?
   
   
2. How will you diagnose my typhoid fever?
   
   
3. What are my treatment options? What are the risks of such treatments?
   
   
4. Am I a carrier of typhoid fever? If so, how do I rid myself of the bacteria?
   
   
5. If I am infected, what precautions do I need to exercise so I don’t infect others?
   
   
6. How can I avoid contracting typhoid fever?
   
   
7. Should I be vaccinated against typhoid fever?
   
   
8. What tips do you suggest for reducing my risk of typhoid fever while traveling?
   
   
9. How can I tell if food is thoroughly cooked?
   
   
10. If I have typhoid fever, will I be required to leave my job working with children?