Typhoid Fever - Cause, Prevention, Treatment and Risk Factors

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.
When treated with antibiotics, most people with typhoid fever feel better within a few days, although a small percentage 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.

Although children with typhoid fever sometimes become sick suddenly, signs and symptoms are more likely to develop gradually — often appearing one to three weeks after exposure to the disease. Here is a review of its symptoms.

Causes

Typhoid fever is caused by a virulent bacterium called Salmonella typhi. Although they're related, S. typhi and the bacterium 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 is endemic, most cases result from contaminated drinking water and poor sanitation. The majority of people in industrialized countries pick up the 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.

 Symptoms

symptoms -1st week
Once signs and symptoms do appear, you're likely to experience:

• Fever, that starts low and increases daily, often to as high as 103 or 104 F (39.4 or 40 C)
• Headache
• Weakness and fatigue
• Dry cough
• Loss of appetite
• Abdominal pain
• Diarrhea or constipation
• Rash

symptoms- 2nd week
If you don't receive treatment for typhoid fever, you may enter a second stage during which you become very ill and experience:

• Continuing high fever
• Either diarrhea or severe constipation
• Considerable weight loss
• Extremely distended abdomen

symptoms- 3rd week
By the third week, you may:

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

Life-threatening complications often develop at this time.

symptoms- 4th week
Improvement may come slowly during the fourth week. Your fever is likely to decrease gradually until your temperature returns to normal in another week to 10 days. But signs and symptoms can return up to two weeks after your fever has subsided.

When to see a doctor
See a doctor immediately if you suspect you have typhoid fever. If you become ill while traveling in a foreign country, call the U.S. Consulate for a list of doctors. Better yet, find out in advance about medical care in the areas you'll visit, and carry a list of the names, addresses and phone numbers of recommended doctors.
If you develop signs and symptoms after you return home, consider consulting a doctor who focuses on international travel medicine or infectious diseases. A specialist may be able to recognize and treat your illness more quickly than can a doctor who isn't trained in these areas.

Prevention

In many developing nations, the public health goals that can help prevent and control typhoid — 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.
The Centers for Disease Control and Prevention recommends being vaccinated 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 about two weeks before exposure.
• 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 as well:

• Wash your hands. Frequent hand-washing is the best way to control infection. Wash your hands thoroughly with hot, soapy water, especially 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 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. Wipe the outside of all bottles and cans before you open them. 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, these measures can help keep others safe:

• Wash your hands often. This is the single most important thing you can do to keep from spreading the infection to others. Use plenty of hot, soapy water and scrub thoroughly for at least 30 seconds, especially before eating and after using the toilet.
• Clean household items daily. Clean toilets, door handles, telephone receivers and water taps at least once a day with a household cleaner and paper towels or disposable cloths.
• 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.
• Keep personal items separate. Set aside towels, bed linen and utensils for your own use and wash them frequently in hot, soapy water. Heavily soiled items can be soaked first in disinfectant.

Treatment And Drugs

Antibiotic therapy is the only effective treatment for typhoid fever.

Commonly prescribed antibiotics

• Ciprofloxacin (Cipro). In the United States, doctors often prescribe this for nonpregnant adults.
• Ceftriaxone (Rocephin). This injectable antibiotic is an alternative for women who are pregnant and for children who may not be candidates for ciprofloxacin.

These drugs can cause side effects, and long-term use can lead to the development of antibiotic-resistant strains of bacteria.

Problems with antibiotic resistance
In the past, the drug of choice was chloramphenicol. Doctors no longer commonly use it, however, because of side effects, a high rate of health deterioration after a period of improvement (relapse), and widespread bacterial resistance.

In fact, the existence of antibiotic-resistant bacteria is a growing problem in the treatment of typhoid, especially in the developing world. In recent years, S. typhi also has proved resistant to trimethoprim-sulfamethoxazole and ampicillin.

Supportive therapy
Other treatment steps aimed at managing symptoms include:

• Drinking fluids. This helps prevent the dehydration that results from a prolonged fever and diarrhea. If you're severely dehydrated, you may need to receive fluids through a vein in your arm (intravenously).
• Eating a healthy diet. Nonbulky, high-calorie meals can help replace the nutrients you lose when you're sick.

 source: http://www.mayoclinic.com/health/typhoid-fever/