TruQuick™ Salmonella Typhi Ag
INTENDED USE TruQuick Salmonella Typhi Ag is a rapid chromatographic immunoassay for the qualitative detection of Salmonella typhi antigens in feces specimens to aid in the diagnosis of Salmonella typhi infection.
Typhoid fever is a life threatening illness caused by the bacterium Salmonella typhi, and was observed by Eberth (1880) in the mesenteric nodes and spleen of fatal cases of typhoid fever.1 The infection is acquired typically by ingestion. On reaching the gut, the bacilli attach themselves to the epithelial cells of the intestinal villi and penetrate to the lamina and submucosa. They are then phagocytosed there by polymorphs and macrophages. The ability to resist intracellular killing and to multiply within these cells is a measure of their virulence. They enter the mesenteric lymph nodes, where they multiply and, via the thoracic duct, enter the blood stream.2 TruQuick Salmonella Typhi Ag is a rapid immunoassay for the qualitative detection of Salmonella typhi antigens in feces specimens, providing results in five minutes. The test utilizes antibodies specific for Salmonella typhi antigens to selectively detect S. typhi antigens in feces.
- To collect fecal specimens: Collect sufficient quantity of feces (1-2 mL or 1-2 g) in a clean, dry specimen collection container to obtain maximum antigens (if present). Best results will be obtained if the assay is performed within 6 hours after collection. Specimen collected may be stored for 3 days at 2-8 C if not tested within 6 hours. For long term storage, specimens should be kept below -20 C.
- To process fecal specimens: For Solid Specimens: Unscrew the cap of the Specimen Collection Tube，then randomly stab the specimen collection applicator into the fecal specimen in at least 3 different sites to collect approximately 50 mg of feces (equivalent to 1/4 of a pea). Do not scoop the fecal specimen. For Liquid Specimens: Hold the dropper vertically, aspirate fecal specimens, and then transfer 2 drops (approximately 100 μL) into the Specimen Collection Tube containing the Extraction Buffer. Tighten the cap onto the Specimen Collection Tube, then shake the Specimen Collection Tube vigorously to mix the specimen and the Extraction Buffer.
- Bring the pouch to room temperature before opening it. Remove the Test Cassette from the foil pouch and use it within one hour. Best results will be obtained if the test is performed immediately after opening the foil pouch.
- Hold the Specimen Collection Tube upright and open the cap onto the Specimen Collection Tube. Invert the Specimen Collection Tube and transfer 3 full drops of the extracted specimen (approximately 120 μL) to the specimen well (S) of the Test Cassette, then start the timer. Avoid trapping air bubbles in the specimen well (S). See illustration below.
- Read results at 5 minutes after dispensing the specimen. Do not read results after 15 minutes. Note: If the specimen does not migrate (presence of particles), centrifuge the extracted specimens contained in the Extraction Buffer vial. Collect 120 μL of supernatant, dispense into the specimen well (S) of a new Test Cassette and start afresh following the instructions mentioned above.
- Ivanoff B. Typhoid fever, global situation and WHO recommendations. SE Asia J Trop Med. Public Health. 1995;26:supp2 1-6.
- Parry CM, Hien TT, Dougan G, et al. Typhoid fever. N Engl J Med. 2002;347:1770-82.