Assembling a geospatial database of tsetse-transmitted animal trypanosomosis for Africa

Abstract Background: African animal trypanosomosis (AAT), or nagana, is widespread within the tsetse-infested belt of sub-Saharan Africa. Although a wealth of information on its occurrence and prevalence is available in the literature, synthesized and harmonized data at the regional and continental scales are lacking. To fill this gap the Food and Agriculture Organization of the United Nations (FAO) launched the Atlas of tsetse and AAT, jointly implemented with the International Atomic Energy Agency (IAEA) in the framework of the Programme Against African Trypanosomosis (PAAT). Methods: The Atlas aims to build and regularly update a geospatial database of tsetse species occurrence and AAT at the continental level. The present paper focuses on the methodology to assemble a dynamic database of AAT, which hinges on herd-level prevalence data as estimated using various diagnostic techniques. A range of ancillary information items is also included (e.g. trypanosome species, survey period, species and breed of animals, husbandry system, etc.). Input data were initially identified through a literature review. Results: Preliminary results are presented for Ethiopia, Kenya and Uganda in East Africa: 122 papers were identified and analyzed, which contained field data collected from January 1990 to December 2013. Information on AAT was extracted and recorded for 348 distinct geographic locations. The presented distribution maps exemplify the range of outputs that can be directly generated from the AAT database

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

Gamma-radiation of

African animal trypanosomoses are vector-borne diseases that cause enormous livestock losses in sub-Saharan Africa, with drastic socio-economic impacts. Vector control in the context of an area-wide integrated pest management program with a sterile insect technique component requires the production of high-quality sterile male tsetse flies. In our study, we evaluated the effect of irradiation on the fecundity of Glossina palpalis gambiensis to identify the optimal dose that will induce maximum sterility while maintaining biological performance as much as possible. In addition, male mating performance was evaluated in semi-field cages. The irradiation doses used were 90, 100, 110, 120, 130, 140, and 150 Gy, and untreated males were used as the control. The results showed that pupal production and emergence rates were higher in batches of females that had mated with fertile males than in those that had mated with irradiated males with any experimental dose. A dose of 120 Gy administered to male flies induced 97–99% sterility after mating with virgin females. For the semi-field cage experiments, males irradiated with 120 Gy showed good sexual competitiveness as compared to fertile males and those irradiated with 140 Gy, considering the level of filling of spermatheca and the number of pairs formed. The optimal radiation dose of 120 Gy found in this study is slightly different from the traditional dose of 110 Gy that has been used in several eradication programmes in the past. The potential reasons for this difference are discussed, and an argument is made for the inclusion of reliable dosimetry systems in these types of studies