Inventory of potential vectors of trypanosoma and infection rate of the Tsetse fly in the National Park of Ivindo, Gabon

Abstract

Background: Trypanosoma's vectors distribution is poorly investigated in Gabon, where Trypanosomiasis historical foci exist. Thus, an active detection of Trypanosoma sp transmission needs to be assessed. Objectives: The present study aims to identify potential vectors of Trypanosoma sp and to evaluate the infection rate of the Tsetse fly in an area of Gabon. Methods: An entomological survey was conducted in the National Park of Ivindo in May 2012 using Vavoua traps. All captured insects were identified. Tsetse were dissected and organs were microscopically observed to detect the presence of Trypanosoma sp. Results: 247 biting flies known as vectors of Trypanosomiasis were caught including 189 tsetse flies, 32 Tabanid and 26 Stomoxys. Tsetse flies had the highest bulk densities per trap per day (ADT = 3 tsetse / trap / day), while the lowest density was found among Stomoxys (ADT= 0.41 Stomoxys / trap / day). The infection rate of flies was 6.3%. Infectious organs were midguts and to a lesser extent salivary glands and proboscis. Conclusion: The presence of Tsetse infected by Trypanosoma highlights an existing risk of trypanosomiasis infection in the National Park of Ivindo.

High Frequency and Activity of Glossina spp., Vectors of Human African Trypanosomiasis along a Secondary Forest-Man Made Transect in Makokou (North East-Gabon)

“…The specific composition of glossines with respect to sex in the prospection sites showed that the females were highly caught than their male counterparts. This result corroborates with that of other authors [23,25].…”

“…The ADT of tsetse flies obtained in our study was barely greater than one. This ADT was higher than that obtained by Mbang Nguema et al [23] and like that obtained by Batu et al [24]. This difference in the ADTs in the different studies could be related to different periods or seasons of prospection.…”

“…This difference in the ADTs in the different studies could be related to different periods or seasons of prospection. Indeed, the present study was carried out during the short rainy season (September to November), while the work of MbangNguema et al [23] was in the rainy season (May 2015). Similarly, the study by Mamoudou et al [25] showed that the ADT of glossines was higher in the early dry season but in the Soudano-Guinean climate.…”

Variations of Glossina sp. and trypanosome species frequency within different habitats in a sleeping sickness focus, Gabon

“…Infection rate was expressed as percentage: number of infected flies/the total number of dissected flies. The diversity of tsetse species in the different biotopes was assessed using The Margalef Diversity Index: D = (S-1) / log N, (where "S" is the number of species and "N "is the total number of individuals harvested) [15].…”

Species Composition and Diurnal Activity Rhythm of Tabanids (Diptera: Tabanidae) at the Ivindo National Park and Its Environs

“…In Gabon, there is no longitudinal study on tabanids, but the few existing reports on this group are cross sectional studies carried out in some protected areas and their environs [7,8,9,10,11].…”