Typhidot test to detect IgG & IgM antibodies in typhoid fever

Abstract

Background & objectives: As typhoid fever is endemic in India, there is a continuing search for a simple test which can be carried out in small laboratories for an early and rapid diagnosis. We have evaluated the Typhidot test for this purpose.

Methods: The Typhidot test was carried out on coded sera according to the manufacturer's instructions. The test was performed on 30 Widal positive sera, 30 sera from blood culture positive patients, 60 Widal negative sera and 30 samples from patients whose blood culture grew Gram negative bacilli (GNB) other than Salmonella Typhi.

Results: Typhidot test was positive for both IgG and IgM in 39 samples, IgM alone in 24 and IgG alone in 2. Of the 30 culture positive samples, 27 were positive by Typhidot. The Typhidot test gave a sensitivity of 100 per cent and specificity of 80 per cent when bacteraemic patients were analysed.

Interpretation & conclusion: The Typhidot is easy to perform, and requires no special equipment or training of staff for interpretation of results. It will be a useful complementary test to blood culture and the Widal test in the diagnosis of typhoid fever.