Typhoid Fever

Contact Precautions

Also known as enteric fever, typhoid fever is a multisystem infection that causes the classic symptoms of fever, malaise, diffuse abdominal pain, and constipation. It occurs in areas where there is poor sanitation and unsafe water conditions. Most infections diagnosed in the United States were acquired during international travel. Approximately 200 to 400 cases are reported annually in the United States, but worldwide it affects over 21 million people. Mortality is about 3% in patients who receive treatment. Ten percent of untreated cases may result in fatality, usually as a result of complications. An attack of typhoid fever confers lifelong immunity, although the patient may become a carrier. Most typhoid fever patients are younger than age 30; most carriers are women older than age 50.

Causes

Typhoid fever is caused by Salmonella typhi, which can only live in humans. S. typhi enters the GI tract and invades the bloodstream via the lymphatics, setting up intracellular sites. During this phase, infection of the biliary tract leads to intestinal seeding with millions of bacilli. Involved lymphoid tissue (especially Peyer patches in the ileum) becomes enlarged, ulcerated, and necrotic, resulting in hemorrhage. The incubation period usually lasts 1 to 2 weeks.

S. typhi is transmitted through stool. A person who eats or drinks food or beverages handled by someone infected with S. typhi who does not practice good hygiene can become infected. Infection may also occur through contaminated water.

Complications

Complications of typhoid fever include intestinal perforation or hemorrhage, abscesses, thrombophlebitis, cerebral thrombosis, pneumonia, osteomyelitis, myocarditis, and acute circulatory failure. Studies have shown that close to 6% of treated patients become chronic carriers. Pancreatitis, acute renal failure, subclinical disseminated intravascular coagulation, and neuropsychiatric manifestations, such as seizures, spastic paraplegia, mania, and depression, may also occur.

Assessment Findings

Abdominal pain and tenderness may develop within hours of ingestion of S. typhi and usually subside before onset of typhoid fever symptoms, which begin 7 to 14 days after ingestion: