Molecular Screening of Trypanosoma spp. in Glossina, Stomoxys and Tabanids in the Moukalaba Doudou National Park (South-West, Gabon)

Abstract

Studies on the knowledge of the pathogens responsible for trypanosomosis remain insufficient in Gabon, particularly in protected areas, such as the Moukalaba Doudou National Park (MDNP). In order to uphold ecotourism in the Moukalaba Doudou National Park (MDNP), an entomological and parasitological study was carried out during the rainy season, from February to March 2017, to identify the trypanosome species harbored by tsetse, stable fly and tabanid vectors in this protected area. Fly collection was carried out using Vavoua and Nzi traps. Trypanosome infections in the flies were detected using the polymerase chain reaction (PCR). In total, seven species of tabanids, five species of tsetse flies and two species of stable flies were collected. These vectors harboured six species of trypanosomes, namely Trypanosoma simiae Tsavo (48%), T. theileri (17%), T. simiae (14%), T. brucei s.l. (10%), T. congolense (9%) and T. vivax (2%). The trypanosome infection rate (IR) varied somewhat among sites. It was 82% in the forest, 92% in settled areas and 95% in the savanna. The high prevalence of trypanosomes in this area raises the possibility of some trypanosomosis transmission risk to humans and animals, but the risk appears to be very low given the low frequency of T. brucei s.l. Studies on the blood meals typing could be done to identify sources and estimate the real risk of infection.