Typhoid Fever

Typhoid Fever, acute infectious disease caused by the typhoid bacillus Salmonella typhi. The bacillus is transmitted by milk, water, or solid food contaminated by feces of typhoid victims or of carriers, that is, healthy persons who harbor typhoid bacilli without presenting symptoms. The World Health Organization (WHO) estimates that globally more than 16 million cases of typhoid fever occur annually, causing 600,000 deaths.

The incubation period of typhoid fever usually lasts one to three weeks. The bacteria collect in the small intestine, from which they enter the bloodstream. This induces the first symptoms, chills followed by high fever and prostration. Victims may also experience headache, cough, vomiting, and diarrhea. The disease spontaneously subsides after several weeks in most instances, but in about 20 percent of untreated cases the disease progresses to pneumonia, intestinal hemorrhage, and even death. Deaths from typhoid fever were greatly reduced by the isolation of the first antibiotic effective against the typhoid bacillus, chloromycetin, or chloramphenicol, derived from a South American mold in the late 1940s. Because of widespread resistance to chloramphenicol, antibiotics from the fluoroquinolone and cephalosporin groups, such as ciprofloxacin and ceftriaxone, are currently the drugs of choice in the treatment of typhoid.

Typhoid is slowly disappearing from the United States because of the prevalence of preventive measures; the number of cases dropped from 5,595 in 1942 to about 400 in 2005, and most of these cases were acquired when people traveled to other countries. Compulsory inspection of milk and water supplies, and the pasteurization of milk in particular, have greatly reduced the incidence of the typhoid bacilli. Of equal importance in the control of typhoid fever has been the recognition of carriers, who can then be prevented from handling food, and improvement of sewage facilities.

Another important factor in the control of typhoid fever is typhoid inoculation of persons exposed to the disease, such as hospital employees and travelers to areas with poor sanitary facilities.