Rapid Diagnostic Test for the Diagnosis of Enteric Fever: A Cross-sectional Diagnostic Study

Introduction: In the present era, the rapid diagnosis of infectious disease is becoming a challenge to the medical field. At this setup, the most common infectious diseases are considered for rapid, accurate diagnosis. Salmonella is one of the most common needed infectious agents to be identified as early as possible. Aim: To identify a specific and sensitive technique for early diagnosis of enteric fever thereby to reduce morbidity and mortality associated with the disease. Materials and Methods: A total of 100 clinically suspected enteric fever cases were tested by blood culture, co-agglutination method, Widal test, and polymerase chain reaction (PCR). For co-agglutination method, blood culture supernatant, urine, and serum were used. Results: Culture positive for Salmonella species was found to be 7.5%. Salmonella typhi was the predominant isolate (86%). S. paratyphi A (14%). Co-agglutination method showed positivity rate of 22.5%. Among the three types of samples, blood culture supernatant showed maximum positivity. 27% positivity was observed with the Widal test. PCR detected (10.8%) of cases. Conclusion: Rapid diagnostic test evaluations to date have used blood culture primarily as the reference standard for typhoid fever diagnosis. Culture provides definitive evidence of infection, but it fails to detect all cases, due to low numbers of the pathogen in the bloodstream and/or prior exposure to antibiotics. Thus, it is evident that PCR is highly specific, and co-agglutination test is highly sensitive for the diagnosis of enteric fever.