Spatial and temporal variations relevant to tsetse control in the Bipindi focus of southern Cameroon

Abstract

BackgroundHuman African Trypanosomiasis (HAT) remains a public health problem in many poor countries. Due to lack of financial resources in these countries, cost-effective strategies are needed for efficient control of this scourge, especially the tsetse vector. It was shown that perennial water sources maintain a favourable biotope for tsetse flies and thus the transmission dynamics of sleeping sickness. The present paper aimed at assessing the transmission dynamics of HAT in a forest environment where the hydrographic network is important.MethodsTwo entomological surveys were carried out in July 2009 and March 2010 in the Bipindi sleeping sickness focus of the South Region of Cameroon. Entomological and parasitological data were collected during both trapping periods (including the climate variations throughout a year) and compared to each other. The level of risk for transmission of the disease during each trapping period was also evaluated at the trap level and materialised on the map of the Bipindi focus.ResultsGlossina palpalis palpalis was the most prevalent tsetse fly species captured in this focus. The overall densities of tsetse flies as well as the risk for transmission of HAT in the Bipindi focus were significantly higher in July than in March. At the trap level, we observed that these parameters were almost constant, whatever the trapping period, when the biotope included perennial water sources.ConclusionsThis study shows that the spatial distribution of traps, as well as the temporal climatic variations might influence entomological and parasitological parameters of HAT and that the presence of perennial water sources in biotopes would favour the development of tsetse flies and thus the transmission of sleeping sickness. These factors should, therefore, be taken into account in order to provide more efficient vector control.

Trypanosome infection rates in tsetse flies in the “silent” sleeping sickness focus of Bafia in the Centre Region in Cameroon

“…The single and mixed infections identified in this study confirm results obtained in tsetse flies and mammals of different African countries [ 16 , 37 – 41 ]. These results show that, whatever the region, single and mixed infections of different trypanosome species are frequent in tsetse flies.…”

“…Beside control activities, studies undertaken to improve our epidemiological knowledge on HAT revealed the presence of Trypanosoma brucei gambiense in various domestic and wild animal species of central African HAT foci [ 6 – 10 ]; confirming thus results obtained in West Africa [ 11 – 13 ]. In addition to that, T. b. gambiense was often associated with animal trypanosomes in the same tsetse fly as well as the same animal of central African HAT foci [ 8 , 9 , 14 – 16 ]. In such context where both diseases share the same environment, coexist in the same host and are transmitted by the same tsetse fly species, control measures targeting human and animal diseases can be developed.…”

Intestinal Bacterial Communities of Trypanosome-Infected and Uninfected Glossina palpalis palpalis from Three Human African Trypanomiasis Foci in Cameroon

“…It is situated between Lolodorf and Kribi, 75 km from the Atlantic Ocean. Although, a 2004 survey identified four tsetse fly species (Grébaut et al, 2004 ), G. p. palpalis was the only species found in this focus since 2007 (Farikou et al, 2010a , b ; Melachio et al, 2011 ; Tchouomene-Labou et al, 2014 ). Bipindi is surrounded by hills and covers several villages, mainly located along the roads.…”

Tsetse Invasion as an Emerging Threat to Socioecological Resilience of Pastoral Communities in Karamoja, Uganda

“…Depending on hydrographic network variations, differences in distribution could exist. For example, a forest region's vector distribution could be uniquely different from that of a savannah [31]. In this regard, the identification of distributional patterns is critical for the execution of control measures [3] and for determining the challenge index that reflects tsetse abundance and infection rates in an area [32].…”