About Typhoid

Typhoid fever is caused by Salmonella typhi bacteria. Typhoid fever is rare in industrialized countries. However, it remains a serious health threat in the developing world, especially for children.

Typhoid fever spreads through contaminated food and water or through close contact with someone who's infected. Signs and symptoms usually include high fever, headache, abdominal pain, and either constipation or diarrhea.

Most people with typhoid fever feel better within a few days of starting antibiotic treatment, although a small number of them may die of complications. Vaccines against typhoid fever are available, but they're only partially effective. Vaccines usually are reserved for those who may be exposed to the disease or are traveling to areas where typhoid fever is common.

Symptoms

Signs and symptoms are likely to develop gradually — often appearing one to three weeks after exposure to the disease.

Early illness

Once signs and symptoms do appear, you're likely to experience:

• Fever that starts low and increases daily, possibly reaching as high as 104.9 F (40.5 C)
• Headache
• Weakness and fatigue
• Muscle aches
• Sweating
• Dry cough
• Loss of appetite and weight loss
• Abdominal pain
• Diarrhea or constipation
• Rash
• Extremely swollen abdomen

Later illness

If you don't receive treatment, you may:

• Become delirious
• Lie motionless and exhausted with your eyes half-closed in what's known as the typhoid state

In addition, life-threatening complications often develop at this time.

In some people, signs and symptoms may return up to two weeks after the fever has subsided.

Causes

Typhoid fever is caused by virulent bacteria called Salmonella typhi (S. typhi). Although they're related, S. typhi and the bacteria responsible for salmonellosis, another serious intestinal infection, aren't the same.

Fecal-oral transmission route

The bacteria that cause typhoid fever spread through contaminated food or water and occasionally through direct contact with someone who is infected. In developing nations, where typhoid fever is endemic, most cases result from contaminated drinking water and poor sanitation. The majority of people in industrialized countries pick up typhoid bacteria while traveling and spread it to others through the fecal-oral route.

This means that S. typhi is passed in the feces and sometimes in the urine of infected people. You can contract the infection if you eat food handled by someone with typhoid fever who hasn't washed carefully after using the toilet. You can also become infected by drinking water contaminated with the bacteria.

Typhoid carriers

Even after treatment with antibiotics, a small number of people who recover from typhoid fever continue to harbor the bacteria in their intestinal tracts or gallbladders, often for years. These people, called chronic carriers, shed the bacteria in their feces and are capable of infecting others, although they no longer have signs or symptoms of the disease themselves.

Risk factors

Typhoid fever remains a serious worldwide threat — especially in the developing world — affecting an estimated 26 million or more people each year. The disease is endemic in India, Southeast Asia, Africa, South America and many other areas.

Worldwide, children are at greatest risk of getting the disease, although they generally have milder symptoms than adults do.

If you live in a country where typhoid fever is rare, you're at increased risk if you:

• Work in or travel to areas where typhoid fever is endemic
• Work as a clinical microbiologist handling Salmonella typhi bacteria
• Have close contact with someone who is infected or has recently been infected with typhoid fever
• Drink water contaminated by sewage that contains S. typhi

Prevention

In many developing nations, the public health goals that can help prevent and control typhoid fever — safe drinking water, improved sanitation and adequate medical care — may be difficult to achieve. For that reason, some experts believe that vaccinating high-risk populations is the best way to control typhoid fever.

A vaccine is recommended if you're traveling to areas where the risk of getting typhoid fever is high.

Vaccines

Two vaccines are available.

• One is injected in a single dose at least one week before travel.
• One is given orally in four capsules, with one capsule to be taken every other day.

Neither vaccine is 100 percent effective, and both require repeat immunizations, as vaccine effectiveness diminishes over time.

Because the vaccine won't provide complete protection, follow these guidelines when traveling to high-risk areas:

• Wash your hands. Frequent hand-washing in hot, soapy water is the best way to control infection. Wash before eating or preparing food and after using the toilet. Carry an alcohol-based hand sanitizer for times when water isn't available.
• Avoid drinking untreated water. Contaminated drinking water is a particular problem in areas where typhoid fever is endemic. For that reason, drink only bottled water or canned or bottled carbonated beverages, wine and beer. Carbonated bottled water is safer than uncarbonated bottled water is.

Ask for drinks without ice. Use bottled water to brush your teeth, and try not to swallow water in the shower.

• Avoid raw fruits and vegetables. Because raw produce may have been washed in unsafe water, avoid fruits and vegetables that you can't peel, especially lettuce. To be absolutely safe, you may want to avoid raw foods entirely.
• Choose hot foods. Avoid food that's stored or served at room temperature. Steaming hot foods are best. And although there's no guarantee that meals served at the finest restaurants are safe, it's best to avoid food from street vendors — it's more likely to be contaminated.

Prevent infecting others

If you're recovering from typhoid fever, these measures can help keep others safe:

• Take your antibiotics. Follow your doctor's instructions for taking your antibiotics, and be sure to finish the entire prescription.
• Wash your hands often. This is the single most important thing you can do to keep from spreading the infection to others. Use hot, soapy water and scrub thoroughly for at least 30 seconds, especially before eating and after using the toilet.
• Avoid handling food. Avoid preparing food for others until your doctor says you're no longer contagious. If you work in the food service industry or a health care facility, you won't be allowed to return to work until tests show that you're no longer shedding typhoid bacteria.