Clinical value of Tubex™ and Typhidot® rapid diagnostic tests for typhoid fever in an urban community clinic in Bangladesh

Tubex™ and Typhidot®, rapid tests for typhoid fever, performed well in evaluations conducted in hospital settings among patients with culture-confirmed typhoid fever. We evaluated these tests in a community clinic in Bangladesh. Blood samples were obtained from 867 febrile patients for culture, Typhidot® and Tubex™ tests. Considering the 43 blood culture-confirmed cases of typhoid fever as typhoid positive and the 24 other confirmed bacteremia cases as typhoid negative, Tubex™ was 60% sensitive and 58% specific, with 90% positive and 58% negative predictive values (NPVs); Typhidot® was 67% sensitive and 54% specific, with 85% positive and 81% NPVs. When blood culture-negative patients and other bacteremia cases together were considered typhoid negative, positive predictive values were only 14% for Tubex™ and 13% for Typhidot®, increasing to only 38% and 20% when restricted to patients with ≥7 days of fever. We conclude that the value of Tubex™ and Typhidot® tests for typhoid fever diagnosis in a community clinic in urban Bangladesh is low.