Revisiting the Immune Trypanolysis Test to Optimise Epidemiological Surveillance and Control of Sleeping Sickness in West Africa

Human African trypanosomiasis (HAT) due to Trypanosoma brucei (T.b.) gambiense is usually diagnosed using two sequential steps: first the card agglutination test for trypanosomiasis (CATT) used for serological screening, followed by parasitological methods to confirm the disease. Currently, CATT will continue to be used as a test for mass screening because of its simplicity and high sensitivity; however, its performance as a tool of surveillance in areas where prevalence is low is poor because of its limited specificity. Hence in the context of HAT elimination, there is a crucial need for a better marker of contact with T.b. gambiense in humans. We evaluated here an existing highly specific serological tool, the trypanolysis test (TL). We evaluated TL in active, latent and historical HAT foci in Guinea, Côte d'Ivoire and Burkina Faso. We found that TL was a marker for exposure to T.b. gambiense. We propose that TL should be used as a surveillance tool to monitor HAT elimination

Long distance transport of irradiated male [i]Glossina palpalis gambiensis pupae[/i] and its impact on sterile male yield

[b]Background[/b]: The application of the sterile insect technique (SIT) requires mass-production of sterile males of good biological quality. The size of the project area will in most cases determine whether it is more cost effective to produce the sterile flies locally (and invest in a mass-rearing facility) or import the sterile flies from a mass-rearing facility that is located in another country. This study aimed at assessing the effect of long distance transport of sterile male [i]Glossina palpalis gambiensis pupae[/i] on adult male fly yield.[b]Methods[/b]: The male pupae were produced at the Centre International de Recherche-Developpement sur l'Elevage en zone Subhumide (CIRDES), Bobo-Dioulasso, Burkina Faso, and shipped with a commercial courier service in insulated transport boxes at a temperature of +/- 10 degrees C to Senegal (+/- 36 h of transport). Upon arrival in the insectary in Dakar, the pupae were transferred to an emergence room and the flies monitored for 3-6 days.[b]Results[/b]: The results showed that the used system of isothermal boxes that contained phase change material packs (S8) managed to keep the temperature at around 10 degrees C which prevented male fly emergence during transport. The emergence rate was significantly higher for pupae from batch 2 (chilled at 4 degrees C for one day in the source insectary before transport) than those from batch 1 (chilled at 4 degrees C for two days in the source insectary before transport) i.e. an average (+/- sd) of 76.1 +/- 13.2% and 72.2 +/- 14.3%, respectively with a small proportion emerging during transport (0.7 +/- 1.7% and 0.9 +/- 2.9%, respectively). Among the emerged flies, the percentage with deformed (not fully expanded) wings was significantly higher for flies from batch 1 (12.0 +/- 6.3%) than from batch 2 (10.7 +/- 7.5%). The amount of sterile males available for release as a proportion of the total pupae shipped was 65.8 +/- 13.3% and 61.7 +/- 14.7% for batch 1 and 2 pupae, respectively.[b]Conclusions[/b]: The results also showed that the temperature inside the parcel must be controlled around 10 degrees C with a maximal deviation of 3 degrees C to maximize the male yield