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**Overview**: Widal Tube Agglutination Test Panel**Introduction**: The Widal Tube Agglutination Test Panel is a diagnostic tool designed for typhoid fever screening using serum samples. In India, typhoid fever remains endemic (~1 million cases/year), with tube method offering semi-quantitative titres for better interpretation than slide in borderline cases. High morbidity from under-testing leading to delayed antibiotics, progression to complications or carrier state. Per microbiology practices aligned with ICMR, National Centre for Disease Control, and IDSP guidelines, the test employs immunoassay for Salmonella Typhi O/H and Paratyphi A/B over 1â€"2 days with high accuracy, valuable for presumptive diagnosis (titre >1:160 or fourfold rise significant). This diagnostic falls under infectious disease screening and targets patients with prolonged fever or food/water exposure, addressing accurate detection to guide ceftriaxone/azithromycin. With elevated morbidity due to underdiagnosis, the test supports public health efforts by enabling reliable typhoid profiling and reducing transmission. Its serum-based approach ensures reliable agglutination detection.**Other Names**: Widal Tube Pnl.**FDA Status**: FDA approved, CLIA certified for biochemistry/immunology, compliant with 2025 standards.**Historical Milestone**: Widal tube test standard in typhoid endemic areas; in India, preferred over slide for accuracy.**Purpose**: The test assesses 4 parameters including Salmonella Typhi O to guide typhoid fever screening, detect antibodies, inform antibiotics.**Test Parameters**: 1. Salmonella Typhi O, 2. Salmonella Typhi H, 3. Salmonella Paratyphi A, 4. Salmonella Paratyphi B.**Pretest Condition**: No fasting required; patients should have prolonged fever.**Specimen**: 3 mL serum in 1 SST, transported within specified times to maintain sample viability.**Sample Stability at Room Temperature**: 8 hours with proper handling to preserve antibody integrity, ensuring reliable test performance.**Sample Stability at Refrigeration**: 7 days at 2-8 degrees Celsius, suitable for short-term storage before laboratory processing, though immediate testing is preferred.**Sample Stability at Frozen**: 6 months at -20 degrees Celsius, allowing long-term storage for retesting, though freezing may affect some analytes.**Medical History**: Patients should provide details on fever duration, water source.**Consent**: Written informed consent is required, detailing the test's purpose, potential risks of untreated typhoid including perforation, benefits of screening, and minimal discomfort from venipuncture.**Procedural Considerations**: The test involves sample processing using immunoassay by trained personnel to ensure sterile technique, avoid hemolysis, and interpret results within 1â€"2 days using provided controls. Laboratories must maintain a controlled environment, adhere to quality assurance protocols.**Factors Affecting Result Accuracy**: Delays beyond stability periods, improper storage conditions, hemolysis can affect results. Correlation with clinical evaluation or additional testing is recommended to confirm findings.**Clinical Significance**: High titre (>1:160) or rising indicates typhoid, necessitating specialist input.**Specialist Consultation**: Infectious disease specialists should be consulted for management.**Additional Supporting Tests**: Blood culture, Typhidot for confirmation.**Test Limitations**: Cross-reactivity/vaccination interference; comprehensive approach required.**References**: Indian Journal of Medical Microbiology 2024, Typhoid Studies India 2023. |
