Overview: Typhidot IgG TestIntroduction: The Typhidot IgG Test detects Salmonella Typhi IgG to confirm past typhoid exposure, preventing recurrence. Aligned with 2023 WHO guidelines, it uses immunoassays for high specificity, supporting infection screening. This test is critical for guiding preventive measures, treatment planning, and improving outcomes in immunology for patients with suspected past typhoid exposure.
Other Names: Typhidot IgG Assay, Salmonella Typhi IgG Test.
FDA Status: Laboratory-developed test (LDT), meeting immunology standards for diagnostic accuracy.
Historical Milestone: Typhoid IgG testing began in the 1990s with rapid diagnostic research. Immunoassay methods improved in the 2000s, enhancing diagnostic precision.
Purpose: Detects Salmonella Typhi IgG to confirm past typhoid exposure, guides preventive measures, and evaluates recurrence risk.
Test Parameters: 1. Salmonella Typhi IgG Antibodies
Pretest Condition: No fasting required. Collect serum or saliva. Report history of typhoid exposure or prior infection.
Specimen: Serum (SST, 2-5 mL), Saliva (sterile container, 1-2 mL). Transport in a biohazard container.
Sample Stability at Room Temperature: 8 hours
Sample Stability at Refrigeration: 7 days
Sample Stability at Frozen: 6 months
Medical History: Document prior typhoid fever, travel to endemic areas, or vaccination history. Include current medications, especially antibiotics.
Consent: Written consent required, detailing the tests purpose, typhoid exposure implications, and risks of sample collection.
Procedural Considerations: Uses rapid dot-blot immunoassay to detect Salmonella Typhi IgG antibodies. Results are available in 1-2 days, supporting clinical decisions. Performed in laboratories, often for past exposure assessment.
Factors Affecting Result Accuracy: Sample hemolysis or improper storage can affect results. Vaccination may cause false positives.
Clinical Significance: Positive IgG confirms past typhoid exposure, guiding vaccination or monitoring. Negative results may require IgM or PCR testing.
Specialist Consultation: Consult an infectious disease specialist for result interpretation and preventive planning.
Additional Supporting Tests: Typhi Dot IgM, blood culture, or typhoid PCR to assess current infection status.
Test Limitations: Non-specific for active infection; clinical correlation is needed. Sample quality affects sensitivity.
References: WHO Typhoid Guidelines, 2023; Clinical Infectious Diseases, Bhutta ZA, 2022.
