Overview: Typhoid DNA Detection TestIntroduction: The Typhoid DNA Detection Test detects Salmonella Typhi DNA to diagnose typhoid fever, causing abdominal pain. Following 2023 WHO guidelines, it uses PCR for high specificity, supporting infection screening. This test is critical for guiding diagnosis, treatment planning, and improving outcomes in molecular pathology for patients with suspected typhoid fever.
Other Names: Typhoid PCR Assay, Salmonella Typhi DNA Test.
FDA Status: Laboratory-developed test (LDT), meeting molecular pathology standards for diagnostic accuracy.
Historical Milestone: Typhoid PCR testing began in the 2000s with molecular diagnostic research. PCR methods improved in the 2010s, enhancing diagnostic precision.
Purpose: Detects Salmonella Typhi DNA to diagnose typhoid fever, guides treatment, and evaluates patients with abdominal pain.
Test Parameters: 1. Salmonella Typhi DNA
Pretest Condition: No fasting required. Collect whole blood, stool, or saliva. Report history of abdominal pain or typhoid exposure.
Specimen: Whole Blood (EDTA, 2-5 mL), Stool (sterile container, 5-10 gm), Saliva (sterile container, 1-2 mL). Transport in a biohazard container.
Sample Stability at Room Temperature: 24 hours
Sample Stability at Refrigeration: 48 hours
Sample Stability at Frozen: Not frozen
Medical History: Document abdominal pain, fever, or history of typhoid exposure. Include current medications, especially antibiotics.
Consent: Written consent required, detailing the tests purpose, typhoid fever implications, and risks of sample collection.
Procedural Considerations: Uses real-time PCR to detect Salmonella Typhi DNA. Results are available in 3-5 days, supporting clinical decisions. Performed in laboratories, often for acute typhoid diagnosis.
Factors Affecting Result Accuracy: Low DNA yield or contamination can affect results. Sample quality impacts specificity.
Clinical Significance: Positive Salmonella Typhi DNA confirms typhoid fever, guiding antibiotic therapy. Negative results may require blood culture or repeat PCR.
Specialist Consultation: Consult an infectious disease specialist for result interpretation and treatment planning.
Additional Supporting Tests: Blood culture, Typhi Dot IgM, or Widal test to confirm typhoid fever diagnosis.
Test Limitations: Non-specific for infection stage; clinical correlation is needed. Sample quality affects sensitivity.
References: WHO Typhoid Guidelines, 2023; Clinical Infectious Diseases, Crump JA, 2022.
