ABSTRACT
Typhoid fever is an unsolved world health problem. Approximately 12 million cases are recognized each year.8 Complications of the disease are not limited to the gastrointestinal tract .
Specific antibiotic therapy for typhoid can only be initiated after the diagnosis is rcmoved from the category of "fever of unknown origin." In approximately half the cases, culture of stool, urine, and blood fails to rcveal the Salmonella. For example, blood cultures show the pathogen in only 40 to 70% of patients .34 Diagnosis may be improved by identifying Salmonella typhi antigens in blood. (See Chapter 8, Immunology.)
In the earliest days of bacteriology, Almquist concluded that the pleomorphic variant of S. typhi was a pathogen. (See Chapter 1 , History). How often the CWD form alone causes disease remains to be determined. Pathogenicity of this variant for tissue culture has been demonstrated (Figure 7 _ 1 ) .42
