TYPHIDOT Rapid IgG/IgM (Combo) is an immunochromatographic assay designed for the qualitative detection and differentiation of specific IgM and IgG antibodies against specific Salmonella typhi OMP antigen in human serum or plasma. It is intended to be used as in vitro diagnostic of typhoid fever. The results obtained should not be the sole determinant for clinical decision.
Typhoid fever is an infectious disease caused by a bacterium, Salmonella typhi. It continues to be a major health problem especially in the Asia Pacific region, the Indian subcontinent, Central Asia, Africa and South America.
Definitive clinical diagnosis of typhoid is unreliable because typhoid fever symptoms mimic other diseases with fever that are common in this part of the world. Clinical presentations vary tremendously among patients and cover a wide spectrum, hence the need for a good laboratory test.
In addition, an accurate diagnosis of typhoid at an early stage is important not only for an aetiological diagnosis for the patient but also to identify individuals that might serve as a source of infection.
Thus all cases of fever should be tested for typhoid and a rapid laboratory tests will be required.
The TYPHIDOT Rapid IgG/IgM (Combo) is an indirect solid-phase immunochromatographic assay. The specific S. Typhi OMP antigen is immobilized onto cellulose nitrate membrane as test lines. When the test sample is added to the sample pad, it migrates upwards. If anti-S. Typhi IgG and IgM antibodies are present in the test sample (serum or plasma), they will react with colloidal gold-anti-human IgG or gold-anti-human IgM to form a complex. The complex will continue to move on the cellulose nitrate membrane and then captured at the test window zone by the immobilized specific S. Typhi OMP antigen, giving a pink-purplish coloured band. The control line contains rabbit anti-mouse IgG antibody which binds with the gold conjugated mouse anti-human IgG or mouse antihuman IgM antibodies. The control band serves as an indication of proper migration plus reagent control.