ABSTRACT
Typhoid is a common problem in developing countries. Cultivation of bacteria and serology [especially Widal test] give unacceptable levels of false-negative and false-positive results, respectively. Patients and In this study, a recently introduced polymerase chain reaction-based technique [which has 100% specificity for Salmonella typhi] was compared with blood culture and Widal test during the first week of illness of 82 suspected cases of typhoid. The respective figures of positivity for PCR, blood culture and Widal test were 71.95%, 34.1%, and 36.5%. A control group of 20 healthy persons gave figures of 0%, 0%, and 33.3%, respectively. We conclude that this PCR-based technique is not only absolutely specific, but also very sensitive and, therefore, much superior to blood culture and Widal test for the early diagnosis of typhoid