A multi-centre evaluation of the card indirect agglutination test for trypanosomiasis (TrypTect CIATT (R))

A version of the card indirect agglutination test for trypanosomiasis, the TrypTect CIATT(R), was evaluated for the diagnosis of Trypanosoma brucei ga mbiense and T. b. rhodesiense sleeping sickness. The results of this antige n-detection test indicated high relative sensitivity (99.3%) and specificit y (99.4%), and also much higher prevalences of infection in the general pop ulations of endemic foci (27.9% for T. b. gambiense and 21.8% for T. 6. rho desiense) than detected by parasitological diagnosis (1.6% and 1.1%, respec tively). TrypTect CIATT detected (and could therefore be used for the diagnosis of) non-patent infections. Among the suspected cases (i.e. those initially foun d to be parasite-negative but to be antigen-positive), trypanosomes were de tected in 29 (4.2%) of those checked at a 3-month follow-up, and 17 more su ch suspects when they were followed up at 6-18 months. Moreover, a high pro portion of blood samples from a random sample of the rest of the suspects t ested positive for trypanosome-specific DNA by PCR (79.9% for T. 6. gambien se and 13.9% for T. b. rhodesiense). ELISA also demonstrated the presence o f anti-trypanosome antibodies in many of the suspects tested (63%, 38%, 24% and 66.9% of those in Cameroon, Cote d'Ivoire, Tanzania, and Malawi, respe ctively). A follow-up of 164 patients treated with melarsoprol revealed that, by 9 mo nths post-treatment, 113 (69.0%) had no detectable trypanosome antigens in their peripheral blood. The test could therefore be used for evaluating che motherapeutic cure, as well as for diagnosis.