ABSTRACT
A version of the card indirect agglutination test for trypanosomiasis, the TrypTect CIATT, was evaluated for the diagnosis of Trypanosoma brucei gambiense and T. b. rhodesiense sleeping sickness. The results of this antigen-detection test indicated high relative sensitivity (99.3%) and specificity (99.4%), and also much higher prevalences of infection in the general population of endemic foci (27.9% for T. b. gambiense and 21.8% for T. b. rhodesiense) than detected by parasitological diagnosis (1.6% and 1.1%, respectively). TrypTect CIATT detected (and could therefore be used for the diagnosis of) non-patent infections. Among the suspected cases (i.e. those initially found to be parasite-negative but to be antigen-positive), trypanosomes were detected in 29 (4.2%) of those checked at a 3-month follow-up, and 17 more such suspects when they were followed up at 6-18 months. Moreover, a high proportion of blood samples from a random sample of the rest of the suspects tested positive for trypanosome-specific DNA by PCR (79.9% for T. b. gambiense and 13.9% for T. b. rhodesiense). ELISA also demonstrated the presence of anti-trypanosome antibodies in many of the suspects tested (63%, 38%, 24% and 66.9% of those in Cameroon, Côte d'Ivoire, Tanzania, and Malawi, respectively). A follow-up of 164 patients treated with melarsoprol revealed that, by 9 months post-treatment, 113 (69.0%) had no detectable trypanosome antigens in their peripheral blood. The test could therefore be used for evaluating chemotherapeutic cure, as well as for diagnosis.
Subject(s)
Antigens, Protozoan/blood , Reagent Kits, Diagnostic , Trypanosoma brucei gambiense/immunology , Trypanosoma brucei rhodesiense/immunology , Trypanosomiasis, African/diagnosis , Adult , Aged , Animals , Child , Female , Follow-Up Studies , Humans , Male , Middle Aged , Reproducibility of Results , Sensitivity and Specificity , Trypanosomiasis, African/drug therapyABSTRACT
Although tsetse control measures were discontinued in Malawi in the early 1950s; the prevalence of sleeping sickness apparently remained at low levels. A sleeping sickness survey conducted in 1987 to 1989 revealed a prevalence of the disease of 3 percent (103/3000). Seven percent (215/3000) of the individuals tested were positive for malaria. 87 individuals traced 2 years after hospital discharge were found well and active in their villages. Four died in villages after hospital treatment. Three relapsed and were readmitted to hospital. Sera from 160 game ranger volunteers and from 82 suspected cases of Rhodesian sleeping sickness were tested by use of ELISA; IFAT and CATT. ELISA and CATT; though not specific; proved to be useful tests for mass screening for human trypanosomiasis. Thick blood smear was found to be the best diagnostic method in this survey
Subject(s)
Trypanosoma brucei brucei , Trypanosomiasis , Tsetse FliesABSTRACT
A study of the extent and distribution of human trypanosomiasis in Malawi. After a period of zero prevalence of sleeping sickness cases during the 1960s; an outbreak occured in Vwasa area in 1984
