Typhoid fever is an acute, life-threatening illness caused by the bacterium Salmonella typhi. It starts as an infection of the intestines, which spreads to the blood and other parts of the body.

Typhoid fever symptoms may be mild to severe and include gradual onset of sustained fever, headache, nausea, loss of appetite, constipation or sometimes diarrhea, and rose-colored spots on the trunk. Symptoms generally appear one to three weeks after exposure. Relapses are possible.

Complications include inflammation of the membrane that lines the wall of the abdomen and the abdominal organs (peritonitis), bleeding and perforation of the intestines, and kidney failure.

Worldwide, the number of typhoid cases for 2000 was estimated at 17 million with 600,000 deaths, although this is considered to be a very conservative number. In the U.S., about 400 cases occur each year; most are acquired while traveling internationally.

Anyone can get typhoid fever, but the greatest risk is to travelers visiting countries where the disease is common.

Typhoid fever is transmitted by food and water contaminated by the stool and urine of patients and carriers. Polluted water is the most common source of typhoid. Other sources of infection have been shellfish taken from sewage-contaminated beds and eaten raw, contaminated foods, and contaminated milk and milk products.

There are currently two vaccines available for typhoid fever. However, because the vaccines are not completely effective, good personal hygiene, including frequent handwashing, and precautions with food and water (see below) are also important.

If you (and others) are traveling to countries where typhoid is present, consider getting vaccinated (consult a healthcare professional or travel clinic about age requirements and waiting time before it becomes effective) and follow sanitary precautions during the trip.

Someone diagnosed with typhoid fever may still pass the infection on to others, even after the symptoms disappear. To minimize this risk:

• Wash hands frequently and thoroughly, especially after going to the bathroom.
• Avoid serving foods to other, whether at home or job setting. Local health laws may require that food handlers not return to work until three consecutive negative stool cultures are confirmed.
• Finish treatment.
• Consult local health laws concerning children in day care, health care workers, and persons in sensitive settings about returning to routine activities.

Consult your healthcare provider, and mention any recent travel to high-risk areas.

Typhoid fever is diagnosed by isolating the bacteria from blood, urine, or stool. Stool samples may also be taken from members of the patient's family to identify any 'healthy' carriers.

Specific antibiotics such as chloramphenicol, ampicillin, or ciprofloxacin are often used to treat cases of typhoid. Treatment and completion of treatment are important. Persons who do not get treatment may continue to have fever for weeks or months . Some excrete bacteria in their stool for up to three months and a small portion of untreated patients become permanent carriers.

Typhoid fever is common in most parts of the world except in industrialized regions. Over the past 10 years, travelers to Asia (particularly the Indian subcontinent), Africa, and Latin America have been especially at risk. The risk is greater for those who travel to developing countries and who travel in smaller cities, villages, and rural areas off the usual tourist routines. To minimize your risk:

• Drink only water that you have boiled or treated with chlorine or iodine. Avoid popsicles and flavored ices that may have been made with contaminated water.
• Other safe drinks include tea or coffee made with boiled water and carbonated, bottled beverages with no ice.
• Avoid undercooked or raw fish and shellfish.
• Avoid raw salads and vegetables.
• Eat only food that's been thoroughly cooked and is still hot, or fruit that you've peeled yourself.
• Avoid food and drinks from street vendors. If not, be sure that meals bought from street vendors are thoroughly cooked in your presence and do not contain any uncooked foods.
• Avoid unpasteurized dairy products and ice cream.
• Practice good personal hygiene, including frequent handwashing.