TruQuick™ Typhoid
TruQuick Typhoid is a rapid immunoassay for the simultaneous detection and differentiation of IgG and IgM antibodies against Salmonella typhi (S. typhi) in whole blood, serum or plasma. It is intended to be used as a screening test as an aid in the diagnosis of infection with S. typhi. Any reactive specimen with TruQuick Typhoid needs to be confirmed with alternative testing method and clinical findings.
Typhoid fever is caused by S. typhi, a Gram-negative bacterium. World-wide, an estimated 17 million cases and 600,000 associated deaths occur annually.1 Patients who are infected with HIV are at significantly increased risk of clinical infection with S. typhi.2 Evidence of H. pylori infection also presents an increase risk of acquiring typhoid fever. Approximately 1-5% of patients become chronic carriers harboring S. typhi in the gallbladder. The clinical diagnosis of typhoid fever depends on the isolation of S. typhi from blood, bone marrow or a specific anatomic lesion. In the facilities that cannot afford to perform this complicated and time consuming procedure, a Widal test (also referred as Weil-Felix Test) is used to facilitate the diagnosis. However, many limitations lead to difficulties in the interpretation of the Widal test.3, 4 In contrast, TruQuick Typhoid is a simple and rapid laboratory test. The test simultaneously detects and differentiates IgG and the IgM antibodies to S. typhi-specific antigen5 in whole blood, serum or plasma as an aid in the determination of current or previous exposure to S. typhi.
- Bring the pouch to room temperature before opening it. Remove the Test Cassette from the sealed pouch and use it as soon as possible. Best results will be obtained if the assay is performed within one hour.
- Place the cassette on a clean and level surface.
- For Serum or Plasma specimen: Hold the dropper vertically and transfer 1 drop of serum or plasma (approximately 40 μL) to the specimen area, then add 2 drops of Buffer (approximately 80 μL) and start the timer. See illustration below.
- For Venipuncture Whole Blood specimen: Hold the dropper vertically and transfer 1 drop of whole blood (approximately 40 μL) to the specimen area, then add 2 drops of Buffer (approximately 80 μL) and start the timer. See illustration below.
- For Fingerstick Whole Blood specimen:
- To use a capillary tube: Fill the capillary tube and transfer approximately 40 μL of fingerstick whole blood specimen to the specimen area of Test Cassette, then add 2 drops of Buffer (approximately 80 μL) and start the timer. See illustration below.
- To use hanging drops: Allow 1 hanging drop of fingerstick whole blood specimen (approximately 40 μL) to fall into the specimen area of Test Cassette, then add 2 drops of Buffer (approximately 80 μL) and start the timer. See illustration below.
- Wait for the colored line(s) to appear. Read the result at 15 minutes, do not interpret the result after 20 minutes.
- Ivanoff BN, Leivne MM, Lambert PH. Vaccination against typhoid fever: Present status. Bulletin of the WHO. 1994;72:957-71.
- Gotuzzo E, Frisancho O, Sanchez J, et al. Salmonella typhi or Salmonella paratyphi in an endemic typhoid area. Archives of Int Med. 1991;151:381-2.
- Clegg A, Passey M, Omena MK, et al. Re-evaluation of the Widal agglutination test in response to the changing pattern of typhoid fever in the highlands of Papua New Guinea. Acta Tropica. 1994;57:255-63.
- Pang T. False positive Widal test in non-typhoid Salmonella infection. SE Asian J Trop Med and Public Health. 1989;20:163-4.
- Ismail A, Hai OK, Kader ZA. Demonstration of an antigenic protein specific for Salmonella typhi. Biochem Biophys Res Commun. 1991;181(1):301-5.