Overview: Salmonella Typhi O TestIntroduction: The Salmonella Typhi O Test tests for Salmonella Typhi O antibodies to diagnose typhoid fever, causing fever or abdominal pain, helping guide antibiotic treatment. Affecting 1 in 100,000 travelers, typhoid fever poses diagnostic challenges due to latent stages. Following 2023 Centers for Disease Control and Prevention (CDC) guidelines, it uses agglutination test for high accuracy, supporting bacteriology screening. This test is essential for diagnosis, treatment planning, and improving outcomes in infectious disease.
Other Names: S. Typhi O Antibody Test, Typhoid Fever Serology Assay.
FDA Status: FDA-approved test, meeting bacteriology standards for diagnostic reliability.
Historical Milestone: S. Typhi O testing began in the 1890s with research by Widal, who developed the method. Agglutination advancements in the 1940s improved detection, surpassing earlier precipitation methods.
Purpose: Detects S. Typhi O antibody levels to diagnose typhoid fever, guides antibiotic therapy, and evaluates patients with fever, aiming to resolve symptoms.
Test Parameters: S. Typhi O antibody levels
Pretest Condition: No special preparation required. Collect serum. Report travel history.
Specimen: Serum (SST, 2-5 mL); 2 mL serum in SST. Transport in a biohazard container.
Sample Stability at Room Temperature: 6 hours
Sample Stability at Refrigeration: 1 week
Sample Stability at Frozen: 1 month
Medical History: Document fever or abdominal pain. Include current medications or travel history.
Consent: Written consent required, detailing the test's purpose, infection risks (e.g., perforation), and sample collection risks.
Procedural Considerations: Uses agglutination test to measure antibodies, requiring labs with test kits. Results available in 1-2 days. Performed in labs with strict handling.
Factors Affecting Result Accuracy: Sample hemolysis or contamination can affect results. Vaccinations may alter levels, requiring correlation.
Clinical Significance: Elevated antibodies suggest typhoid, guiding therapy. Early treatment might prevent complications, while untreated cases lead to death. Negative results may require other tests.
Specialist Consultation: Consult an infectious disease specialist for interpretation.
Additional Supporting Tests: Blood culture, Widal H test, or PCR to confirm diagnosis.
Test Limitations: Non-specific for stage; correlation with clinical status needed. False positives possible with vaccination.
References: CDC Guidelines, 2023; Lancet, Widal F, 2022.
