Distribution and Density of Tsetse Flies (Glossinidae: Diptera) at the Game/People/Livestock Interface of the Nkhotakota Game Reserve Human Sleeping Sickness Focus in Malawi

Abstract

In large parts sub-Saharan Africa, tsetse flies, the vectors of African human or animal trypanosomiasis, are, or will in the foreseeable future, be confined to protected areas such as game or national parks.Challenge of people and livestock is likely to occur at the game/livestock/people interface of such infested areas.Since tsetse control in protected areas is difficult, management of trypanosomiasis in people and/or livestock requires a good understanding of tsetse population dynamics along such interfaces. The Nkhotakota GameReserve, an important focus of human trypanosomiasis in Malawi, is a tsetse-infested protected area surrounded by a virtually tsetse-free zone. The abundance of tsetse (Glossina morsitans morsitans) along the interface, within and outside the game reserve, was monitored over 15 months using epsilon traps. A land cover map described the vegetation surrounding the traps. Few flies were captured outside the reserve. Inside, the abundance of tsetse at the interface was low but increased away from the boundary. This uneven distribution of tsetse inside the reserve is attributed to the uneven distribution of wildlife, the main host of tsetse, being concentrated deeper inside the reserve. Challenge of people and livestock at the interface is thus expected to be low, and cases of trypanosomiasis are likely due to people and/or livestock entering the reserve. Effective control of trypanosomiasis in people and livestock could be achieved by increasing the awareness among people of dangers associated with entering the reserve.

Geostatistical models using remotely‐sensed data predict savanna tsetse decline across the interface between protected and unprotected areas in Serengeti, Tanzania

“…Similar declines in G. morsitans have been noted in Zambia and Malawi (Ducheyne et al., ; Gondwe et al., ; Mweempwa et al., ). Our results indicate that loss of woody vegetation explains, in part, such a decline in northern Serengeti, Tanzania.…”

Tsetse fly distribution and occurrence of Trypanosoma species among cattle and goats around Queen Elizabeth National park, Uganda

“…The thickets and shrubs had the highest number of tsetse y catches. The results agree with literature which suggests that G. pallidipes inhabits woodland savannas and thickets (16,20,21). Tsetse ies are very sensitive to changes in the environment and the ecology of an area.…”

“…Tsetse ies are very sensitive to changes in the environment and the ecology of an area. Factors such as temperature, humidity and vegetation cover are important in provision of shade and maintenance of suitable micro-climate and a habitat for hosts of tsetse ies (4,19,20,22).…”

Transmission Dynamics of Rhodesian Sleeping Sickness at the Interface of Wildlife and Livestock Areas

“…In Malawi, 15 times more G. m. morsitans were caught inside the Nkhotakota Game Reserve than in suitable habitat (predicted from satellite imagery) outside the reserve (when numbers caught were adjusted by trapping effort). This difference was attributed to human activity, destruction of tsetse habitat, and low density of hosts [49]. In Zambia, fly-round catches of G. m. morsitans were from four to 280 times higher in natural habitats compared with natural habitats fragmented by agriculture [48,50].…”

“…This has led to an overall decline in habitat suitable for tsetse. However, protected areas and their surroundings form islands that can sustain populations of savannah tsetse: G. morsitans, G. swynnertoni, and G. pallidipes [45,49]. These areas are often surrounded by significant landuse change [16], and fragmented tsetse habitat [48,50], but habitat distribution varies from hard borders where land use changes quickly (for example in Rumphi, Malawi [51] and Western Serengeti, Tanzania) to more gradual gradients in land use and tsetse habitat (as seen in Luangwa Valley, Zambia [48,50]).…”