Comparison of Molecular Detection Method (Nested Polymerase Chain Reaction) with Blood Culture and Paired Widal test for the Rapid Diagnosis of Typhoid Fever.

Typhoid fever is a major health problem in developing countries in spite of the use of antibiotics and the development of newer antibacterial drugs. Blood culture & serological tests (specially Widal test) which are invariably done in Bangladesh for typhoid fever diagnosis give unacceptable levels of false negative & false positive results respectively. This cross sectional study was done at Bangabandhu Sheikh Mujib Medical University from March 2013 to February 2014. In this study, a polymerase chain reaction-based technique (which has 100% specificity for Salmonella Typhi) was compared with blood culture and widal test among 80 clinically suspected cases of typhoid fever. PCR showed maximum positivity rate (70%) followed by widal test (43.75%) and blood culture (16.25%). PCR showed positive results for 17(48.6%) of 35 typhoid patients with negative results with blood culture and widal test. The results of the study revealed that PCR is rapid and reliable diagnostic technique for detection of S. Typhi in clinically suspected typhoid fever cases, as compared to most commonly done methods such as conventional blood culture, widal test applied.