Typhoid fever is an infectious disease caused by the bacteria Salmonella typhi and Salmonella paratyphi. This disease is commonly found in developing countries, particularly in areas with poor sanitation. Quick and accurate diagnosis is crucial for ensuring appropriate treatment, especially since typhoid fever can lead to serious complications if not properly managed. Various testing methods have been developed to detect typhoid infections, including the Widal test, Salmonella Rapid Test, and Tubex. Each of these methods has different characteristics and mechanisms of action, which can affect their effectiveness and speed of diagnosis.

1. Widal Test

The Widal test is a classic method used to detect antibodies against the O and H antigens of Salmonella typhi in a patient's serum. This process involves an agglutination reaction, where the patient’s serum is mixed with known antigens. If specific antibodies against these antigens are present in the serum, agglutination occurs, which can be observed visually. The Widal test is often used in areas with limited healthcare facilities, as this method is relatively simple and cost-effective.

However, the Widal test also has limitations. The results can be influenced by factors such as prior vaccination or infections with other Salmonella bacteria, which may lead to false-positive results. Nevertheless, the Widal test remains a popular choice, particularly as an initial method for detecting typhoid infections.

In addition, Isotek offers a product that complements the Widal test, designed for enhanced accuracy and ease of use in detecting Salmonella infections, further improving diagnostic capabilities in clinical settings. The product is named the BEACON Salmonella 8 Antigen Slide and Tube Test Kit with Controls, available as a kit (1 set) designed for the serological examination of Salmonella typhi and Salmonella paratyphi (A, B, C) infections.

This product is recommended for use by professionals in a clinical laboratory environment and includes the following features and benefits BEACON Salmonella 8 Antigen Slide and Tube Test Kit with Controls:

• Complete Selling Box: BEACON Salmonella 8 Antigen Slide and Tube Test Kit with Controls contains 8 bottles of reagents, positive control, negative control, circle slide glass, and an insert pack, making it practical for the complete detection of Salmonella typhi and Salmonella paratyphi (A, B, C).
• Safe Packaging: Packed in a duplex carton, wrapped in plastic, and labeled with QC stickers to reduce the risk of infection during shipping.
• Color-Coded Antigen Suspension: The blue and red colors of the antigen suspension make it easy for health professionals to read and differentiate results.
• Advanced Technology: The Salmonella 8 Antigen Slide and Tube Test Kit with Controls is produced using PHEB (Post Harvesting Electrolyte Binding) technology, ensuring optimal specificity and sensitivity while avoiding test result errors.
• Clear Glass Pipette: The pipette is made of clear glass, facilitating easy suspension collection for operators.
• Quality Control: Equipped with positive and negative controls to ensure the reagent quality remains intact. Additionally, the reagent bottle is cushioned with foam for safe storage against bumps.
• Certifications: The product has CE certification, ISO 9001:2015, ISO 13485:2016, and an AKL permit from the Indonesian Ministry of Health, guaranteeing its quality.
• Shelf Life: The product has an expiration date of 2 years post-production, allowing users to keep a certain amount of stock without worrying about quality degradation.

2. Salmonella Rapid Test

The Salmonella Rapid Test is a rapid testing tool designed to detect Salmonella typhi antigens directly from a patient’s blood. This method provides results in a short time, usually between 15 and 30 minutes, making it a suitable option for the early detection of typhoid fever. During the process, the patient’s blood is processed to identify the presence of specific antigens from Salmonella typhi.

The primary advantage of the Salmonella Rapid Test is its ability to deliver faster results compared to the Widal test. Additionally, this method is more specific because it directly detects antigens, which reduces the likelihood of false-positive results. However, it is important to note that the results from the Salmonella Rapid Test should still be confirmed with other methods, especially in areas with high prevalence, to ensure diagnostic accuracy.

In addition to this, PT Isotekindo Intertama offers the ACCU-TELL® Typhoid Cassette (Whole Blood/Serum/Plasma), which is an immunochromatographic rapid test for the qualitative detection of IgG and IgM antibodies against Salmonella typhi in whole blood, serum, or plasma specimens. PT Isotekindo Intertama is the official distributor of the ACCU-TELL® Typhoid Cassette (Whole Blood/Serum/Plasma) and is registered with the Indonesian Ministry of Health (KEMENKES RI).

This product is recommended for use by professionals in a clinical laboratory environment and includes the following features and benefits:

• Complete Kit: Includes test cassette, plastic pipette, buffer (sufficient for 25 tests), and insert pack.
• Sample Flexibility: Works with whole blood, serum, or plasma.
• Fast Results: Interpretation within 15 minutes.
• High Sensitivity and Specificity:
  • IgG: Sensitivity 89.5%, Specificity 97.2%
  • IgM: Sensitivity 87.9%, Specificity 97.4%
• Quality Assurance: CE certified and AKL approved by KEMKES RI; 2-year shelf life.

3. Tubex Test

The Tubex test is a diagnostic assay that detects specific IgM antibodies against the O9 antigen of Salmonella typhi using the principle of magnetic agglutination inhibition. This method is designed to provide higher sensitivity and specificity compared to the Widal test and the Salmonella Rapid Test. The Tubex test is highly effective for detecting acute typhoid infections, as it can identify antibodies at an early stage of infection.

The Tubex test involves taking a blood sample and conducting a more detailed laboratory analysis. While the cost and equipment required for the Tubex test may be higher than for other methods, the results obtained are valuable for accurate diagnosis. The Tubex test is suitable for use in hospitals or laboratories with more advanced facilities, where diagnostic accuracy is a top priority.

Conclusion

References:

1. Bhutta, Z. A. (2006). Current concepts in the diagnosis and treatment of typhoid fever. BMJ, 333(7558), 78-82.
2. Choo, K. E., Davis, T. M. E., Ismail, A., et al. (1999). Rapid serologic diagnosis of typhoid fever by the detection of IgM antibodies to the Salmonella typhi lipopolysaccharide antigen using an enzyme immunoassay: Comparison with the Widal test. The American Journal of Tropical Medicine and Hygiene, 60(4), 654-658.
3. Fadeel, M. A., House, B., Wasfy, M. M., et al. (2011). Evaluation of a newly developed immunoassay for the diagnosis of acute typhoid fever in an endemic area. Clinical and Vaccine Immunology, 18(5), 784-788.
4. Olopoenia, L. A., & King, A. L. (2000). Widal agglutination test - 100 years later: Still plagued by controversy. Postgraduate Medical Journal, 76(892), 80-84.
5. Tharmaphornpilas, P., Chantra, S., Pengsaa, K., Tran Minh, N. N., & Taybouavone, T. (2009). Diagnostic value of rapid tests for typhoid fever in endemic areas. Journal of Tropical Pediatrics, 55(6), 433-434.
6. World Health Organization. (2003). Background document: The diagnosis, treatment, and prevention of typhoid fever. WHO.