Typhoid fever

Typhoid fever is an acute systemic febrile infection caused by Salmonella typhi, a serotype of Salmonella enterica serotype Typhi. Spreading by fecal-oral route, it has epidemic potential, but has largely been prevented by sewage and water treatment in the developed world. For example, there are approximately 400 cases per year in the U.S,, mostly among travelers. There is a vaccine, but recommended only for travelers to endemic areas.

Worldwide, there are an estimated 21 million cases with 200,000 deaths (0.5% of worldwide deaths. Untreated, the illness may last for 3 to 4 weeks and death rates range between 12% and 30%. Relapse occurs in as many as 10% of patients, while 1-5% of patients become long-term carriers following recovery. There are areas of the world, such as Central Asia,  Indonesia and Papua New Guinea, with an incidence of 2%. In these "hot spots", typhoid fever ranks among the 5 most common causes of death, 91% among children.

Diagnosis
Presence in an endemic area should be a warning. Fever and chills are common, with many patients having more bradycardia than would seem appropriate for the fever. Nonspecific symptoms headache, sore throat, muscle pain, and weakness. Skin rash and cervical adenopathy are common.

There can be a wide range of gastrointestinal disturbances of all sorts. Occasionally, there are alterations in mental state, convulsions, and eye pain with decreased vision.

Specific rapid immunoglobulin M (IgM) and immunoglobulin tests give results in minutes to hours.

Treatment
Even with the risk of aplastic anemia, chloramphenicol had long been the drug of choice. Increasing microbial resistance as well as the other risks now make oral fluoroquinolones, usually ciprofloxacin, the drugs of choice, except in children and pregnant women. In that populations, the drug of choice is parenteral ceftriaxone. Fluoroquinolones may have improved effectiveness in preventing the relapse and carrier states.

Resistance has been increasing to fluoroquinolones, as well as to the alternative drugs, trimethoprim-sulfamethoxazole, and ampicillin.