Comparative Study for Early Diagnosis of Typhoid Fever by Blood Culture, Widal Test and Polymerase Chain Reaction in a Tertiary Hospital, Bangladesh

Background: Typhoid fever is an infectious disease in developing countries like Bangladesh. Laboratory diagnosis of typhoid fever is a major challenge still now. PCR could be a reliable test in the diagnosis and management of typhoid fever. Objective: To detect the flagelline gene (fli C) of salmonella typhi from blood by nested PCR for early and reliable diagnosis of typhoid fever and to compare it with blood culture and Widal test. Methods: This was a descriptive type of comparative study conducted among clinically suspected patients of typhoid fever attending the outpatient department of Barind Medical College, Rajshahi, Bangladesh. In this study, 80 clinically suspected patients of typhoid fever were included. From all patients, blood was collected, blood culture, Widal test and nested PCR targeting the flagelline gene (fli C) of Salmonella typhi were done. Results: The positivity rate of PCR and blood culture was 83.7% and 15% respectively. The positivity rate of PCR was significantly higher than blood culture (P< 0.05).With the nested PCR, S.typhi DNAs were detected from blood specimens of 82 % patients among the suspected typhoid fever cases on the basis of clinical features with negative cultures. Conclusion: PCR technique could be used as a novel diagnostic method of typhoid fever, particularly in culture negative cases in an endemic country like Bangladesh.