Typhoid fever

Medical quality assurance by Dr. Albrecht Nonnenmacher, MD at February 27, 2016
StartDiseasesTyphoid fever

In the United States, there are about 6,000 annual cases of typhoid fever or typhoid. About three-quarters of these cases are contracted when American inhabitants travel abroad. If caught early, these cases can be successfully treated using antibiotics. However, in developing countries, typhoid is a common threat.

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Definition & Facts

Typhoid is an acute illness that is characterized by fever and is caused by bacteria known as Salmonella typhi (S. typhi). The infection can also be caused by related bacteria known as Salmonella paratyphi that often cause a less severe illness. The bacteria are deposited on food or water by a human carrier and then spread through the fecal-oral route to other people in the surrounding areas.

Since the 1900s, the incidence of typhoid fever in the US has remarkably reduced. This improvement is attributed to better sanitation standards. But, countries like Egypt, Pakistan and India are known to be high-risk areas for typhoid. Globally, the typhoid fever affects over 21 million individuals annually, and about 200,000 people die from this disease.

Symptoms & Complaints

Typhoid fever has an incubation period of about one to two weeks, and the disease is known to last between one and three weeks. The early symptoms of the illness include fever and abdominal pain. As the disease worsens, a high grade fever of 103 degrees Fahrenheit (39.5 degrees Celsius) or above as well as severe diarrhea occur. Some people affected with the illness develop blemishes (tiny, red spots) on the chest and abdomen. Other symptoms include:

Causes

S. typhi is spread through contaminated water and contaminated food. If an individual eats or drinks something that is contaminated with the bacteria, the bacteria enter the body. The bacteria travel into the intestines, and then into the blood. They travel through the blood to the lymph nodes, liver, spleen, gallbladder, and other parts of the body.

Infected people urinate and defecate living bacteria in their urine and feces. They are often contagious for several days before any symptoms of the disease set in and don’t know they need to take extra precautions.

Without proper hand washing, the typhoid bacilli can be transferred to water and food, and from there, to other people. They can also be spread from one individual to another through contaminated fingers. Close to 4 percent of the people, whether treated or not, become asymptomatic carriers of the S. typhi. This means they continue to shed the bacteria in their excrement for at least a year, and often throughout their lives, but these people don’t have any symptoms of typhoid.

Every country has a small number of typhoid carriers. Even the US and Canada report tens of locally transmitted typhoid cases annually though most of these cases are among immigrating or traveling people who are infected when they arrive.

Diagnosis & Tests

After ingesting contaminated water or food, the S. typhi invade the small intestines and temporarily get access to the bloodstream. The bacteria are transported by white blood cells to the bone marrow, spleen, and liver where they multiply and again enter the bloodstream. At this point, people develop symptoms.

The bacteria invade the biliary system, gallbladder, and lymphatic system of the bowel. They then multiply in large numbers. These bacteria enter the gastrointestinal tract and can be identified in stool samples. If the test results are unclear, blood samples can be used to make the diagnosis. The complete blood count (CBC) shows a high number of white blood cells. A blood culture done in the first week after the fever can show the S. typhi bacteria. Other tests that can help in the diagnosis include:

Treatment & Therapy

The patient may be given electrolytes and fluids intravenously (IV). One may also be asked to drink pure water with electrolytes. A sick individual is usually given antibiotics to kill the bacteria. Currently in the world, there are increasing cases of antimicrobial resistance. Thus, the healthcare provider will refer to current recommendations before prescribing antibiotics.

The antibiotics given include ciprofloxacin, ceftriaxone, and levofloxacin. These medications usually remove the symptoms within a week. However, people with severe typhoid may be given glucocorticoids like dexamethasone. If properly treated, very few people die of typhoid, but they are still likely to be infectious for at least eight days after the symptoms subside.

Some people may remain infectious and keep excreting the bacteria in their stool for about three months or more. However, this state is unlikely to occur except when such a person has gallbladder disease.

Prevention & Prophylaxis

It is recommended for people traveling outside the US to areas prone to typhoid fever to receive a typhoid vaccine. The CDC website has information about which areas are prone to typhoid. Travelers should consult their physicians if they need to bring electrolyte packets in case they get sick. Also:

  • When traveling, individuals should only drink bottled or boiled water, and eat food that has been sufficiently cooked
  • Waste disposal, water treatment, and protecting food from contamination are vital public measures that people must take.
  • Typhoid carriers must not be allowed to serve as food handlers
  • Careful hand washing before food handling and after bowel movements will help in preventing the spread of enteric fever
  • Disinfect or boil water before drinking it. There are many disinfectant liquids and tablets available in most pharmacies
  • Peel vegetable and fruit skins before eating
  • Keep flies away from food
  • Avoid foods or drinks from street vendors

Typhoid fever is an acute disease that, if left untreated, can be fatal. Thus, everyone is advised to be cautious, especially when traveling abroad, to prevent contracting the disease by following the recommended advice.