Majority of typhoid cases are contracted while traveling abroad; Ask the Doctors

Dear Doctor: How common - and dangerous - is typhoid fever? I read that a day care center was recently shut down because a student there was sick with it. I thought typhoid was a thing of the past.

Dear Reader: Of the 5,700 cases of typhoid fever reported each year in the United States, the majority - about 75 percent, according to the federal Centers for Disease Control and Prevention - are contracted while traveling abroad. That turned out to be the case with the story you're referring to. The day care facility, located in Quincy, Massachusetts, was shut down after a child was diagnosed with the disease. People who had contact with the sick child underwent testing and no other cases of the disease were found. The child who became ill received treatment and recovered.

Typhoid fever is a life-threatening illness caused by Salmonella typhi, a type of bacterium. It's contracted by an estimated 21 million people worldwide each year and kills more than 220,000 of them. Symptoms include nausea, abdominal cramps, fatigue, headache, vomiting, loss of appetite and a dangerously high fever. These are similar to symptoms of the flu, which can sometimes delay an accurate diagnosis in areas where typhoid is not common. What distinguishes the illness, however, is the severity of these symptoms and the length of time for which they persist.

A diagnosis of typhoid fever is suspected when a patient has recently traveled internationally to an area where the disease is common. The diagnosis is confirmed via a sample of stool, urine, blood or bone marrow. The sample is placed in a special medium that allows the bacterium to flourish. The resulting culture is then visualized under a microscope to see whether the bacterium responsible for typhoid is indeed present. A typhoid fever diagnosis may also be confirmed with a test that detects the antibodies the immune system sends out in response to the typhoid bacterium, or a test that identifies typhoid DNA in the blood. The sole treatment for typhoid fever is antibiotics.

Someone is considered to be a typhoid carrier whether or not the bacterium has caused them to become ill. (Not everyone who is a typhoid carrier gets sick.) However, the bacterium is present in the feces, and sometimes the urine, of all carriers. You can contract the disease if you eat food prepared by an infected individual who has not washed his or her hands properly after using the bathroom. It can also be passed along in contaminated water. Before the sanitation infrastructure in the U.S. was built out, including our public sewer and water treatment systems, typhoid fever was widespread. In the decades between 1920 and 1950, when many of the public sanitation utilities we now rely on were built, cases of typhoid fever dropped from 100 cases per 100,000 people, to fewer than two cases per 100,000.

Although there are typhoid vaccines that can help prevent infection, they are not 100 percent effective. For that reason, even when they have been vaccinated, travelers to regions where the disease is common should take precautions. Never drink untreated water, avoid raw or undercooked foods, and be sure to wash hands often.

Eve Glazier, M.D., MBA, is an internist and associate professor of medicine at UCLA Health. Elizabeth Ko, M.D., is an internist and assistant professor of medicine at UCLA Health. Send your questions to askthedoctors@mednet.ucla.edu, or write: Ask the Doctors, c/o Media Relations, UCLA Health, 924 Westwood Blvd., Suite 350, Los Angeles, CA, 90095. Owing to the volume of mail, personal replies cannot be provided.

Credit: Dr. Eve Glazier; Dr. Elizabeth Ko