General information about this test:
The NADAL® Salmonella typhi Test is a rapid qualitative immunological test for detection of Salmonella typhi antigens in human faeces samples. This test is designed to aid diagnosis typhoid fever and is intended for professional use only.
Reagents and material supplied:
- 10 NADAL® Salmonella typhi test cassettes
- 10 specimen collection tubes with buffer
- 1 package insert
Test time: 10 min
Performance characteristics:
The detection limit of the NADAL® Salmonella typhi Test is 1.25 x 107 CFU/ml.
The NADAL® Salmonella typhi Test does not show any cross-reactivity with the following common intestinal pathogens: E. coli O157:H7, Campylobacter, Staphylococcus aureus, Yersinia enterocolitica, H. pylori, Shigella, Clostridium difficile, Listeria monocytogenes.
The specificity and sensitivity data for The NADAL® Salmonella typhi Test were obtained using Salmonella typhi culture. The test results were confirmed by comparison with another immune-chromatographic test - Singlepath® Salmonella, Merck.
Sensitivity: >99%
Specificity: >99%.
Test principles:
The NADAL® Salmonella typhi Test detects Salmonella typhi antigens in human stools samples. In case of positive result, during testing, the specimen reacts with anti-Salmonella typhi antibodies conjugated to colored particles and precoated onto the conjugate pad of the test. The mixture then migrates along the membrane by capillary action and interacts with specific antibodies on the membrane - a colored line appears in the test line (T) region of the membrane. Obtaining green coloration in the control (C) region of the test guarantees that enough volume of specimen has been added to the wells and the test was run properly.
Clinical significance:
Salmonella enterica-caused syndromes can be divided into two groups: typhoid fever caused by S. enterica serovars typhi and paratyphi, and a range of clinical syndromes, including diarrhoeal diseases caused by non-typhoid salmonellae (NTS) of which there are around 2,500 serovars. Typhoid fever is human-restricted and highly adapted invasive systemic disease of adults and children that shows little association with immunosuppression. In contrast, NTS infect a wide range of vertebrates and severe diseases caused by NTF are usually related to compromised immune system (e.g. due to HIV-infection). Many young African children suffering from severe anaemia, malnutrition and HIV infection, are also affected by NTS-caused diseases.