Building Endogenous Capacity for the Management of Neglected Tropical Diseases in Africa: The Pioneering Role of ICIPE

Masiga, Daniel K.; Igweta, Lilian K; Saini, R. K.; Ochieng'-Odero, James P.; Borgemeister, Christian

doi:10.1371/journal.pntd.0002687

Cited by 8 publications

(8 citation statements)

References 28 publications

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“…A total of 80 standard Nguruman (NGU) traps (40 traps in each season) were deployed around the watering and grazing areas for the trapping of tsetse and other biting flies. The NGU trap is used to catch savanna flies, such as Glossina pallidipes , and is very effective and easily constructed from locally available materials ( 32 ). All traps were uniformly baited with acetone and 3-week-old cow urine deployed at an interval of 200–250 m ( 33 ).…”

Section: Methodsmentioning

confidence: 99%

Seasonal Patterns: Bovine Trypanosomosis, Glossina pallidipes Density, and Infection in Rift Valleys of Gamo Zone, Southern Ethiopia

Seyoum

Tora

Kore³

et al. 2022

Front. Vet. Sci.

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Bovine trypanosomosis is a parasitic disease causing serious economic losses in livestock productivity and agricultural development. The disease has been reported in different parts of Ethiopia. However, seasonal pattern of trypanosomosis, tsetse fly apparent density, and infection are very limited in the southern rift valley of the country, particularly in Gamo Zone. Therefore, the objective of this cross-sectional study design was to estimate seasonal prevalence of bovine trypanosomosis, assessing tsetse fly apparent density and its infection by trypanosomes. For the parasitological study, a total of 600 cattle (300 in each season) were sampled and assayed using the buffy coat technique. A total of 80 standard NGU traps were deployed around the watering and grazing areas for the entomological survey. An overall prevalence of trypanosomosis was 10.17% (61/600), of which 7.33% (22/300) and 13% (39/300) accounted for the dry and wet seasons, respectively. The prevalence of trypanosomosis was significantly higher during the wet season (OR = 2.47; p < 0.05), in black coat color (OR = 7.2, p < 0.05), and poor body-conditioned (OR = 3.15; p < 0.05) animals. Two species of trypanosomes, Trypanosoma congolense, 68.85% (42/61), and Trypanosoma vivax, 31.15% (19/61), were circulating in the area. The mean PCV value in infected animals (22.56 ± 4.61) was significantly lower than in non-infected animals (25.3 ± 4.75). Entomological result indicated that Glossina pallidipes (G. pallidipes) was the only species of tsetse found in the study area. Totally, 3,789 flies were caught of which 81.42% (3,085/3,789) belong to G. pallidipes and 18.58% (704/3,789) were other biting flies. The overall apparent density of G. pallidipes was 12.85 flies/trap/day (FTD). Relatively higher G. pallidipes/trap/day were caught in the wet season (13.64 F/T/D) than in the dry season (12.07F/T/D). Of the flies caught, 342 G. pallidipes were randomly selected and dissected. The overall proportion of G. pallidipes infection was 18.42% (63/342) of which 12.28% (21/171) and 24.56% (42/171) were accounted in the dry and wet seasons, respectively. Infection in G. pallidipes was significantly higher during the wet season (OR = 2.32; p < 0.05) and in park grazing areas (OR = 2.45; p < 0.05). In conclusion, trypanosomosis is the major challenge for cattle productivity in the district. So this study warrants the need for strengthening the vector and parasite control interventions in the area.

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Section: Methodsmentioning

confidence: 99%

Seasonal Patterns: Bovine Trypanosomosis, Glossina pallidipes Density, and Infection in Rift Valleys of Gamo Zone, Southern Ethiopia

Seyoum

Tora

Kore³

et al. 2022

Front. Vet. Sci.

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“…Here, the blue color of the traps and targets attracts tsetse flies, the black panel triggers landing responses, and the odor cues lure them beyond the vicinity of the trap [13]. For instance, in the Ngu tsetse trap, a blue and black paneled trap for Glossina pallidipes patented by icipe [14,15], cow urine and acetone are combined with the visual trap as odor cues to enhance trap attractiveness [14]. However, the application of traps and targets is limited to small defined areas [3] and offers no protection to freely-grazing livestock.…”

Section: Introductionmentioning

confidence: 99%

“…Innovative mobile tools amenable to African nomadic pastoralists to protect their livestock from tsetse bite and trypanosomosis infection has led to the development of the tsetse repellent technology [14,16]. Certain vertebrates such as waterbuck, zebra, wildebeest and impala are abundant in tsetse habitat but not preferred for blood meals [17–20].…”

Section: Introductionmentioning

confidence: 99%

Zebra skin odor repels the savannah tsetse fly, Glossina pallidipes (Diptera: Glossinidae)

et al. 2019

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Background African trypanosomosis, primarily transmitted by tsetse flies, remains a serious public health and economic challenge in sub-Saharan Africa. Interventions employing natural repellents from non-preferred hosts of tsetse flies represent a promising management approach. Although zebras have been identified as non-preferred hosts of tsetse flies, the basis for this repellency is poorly understood. We hypothesized that zebra skin odors contribute to their avoidance by tsetse flies. Methodology/Principal findings We evaluated the effect of crude zebra skin odors on catches of wild savannah tsetse flies ( Glossina pallidipes Austen, 1903) using unbaited Ngu traps compared to the traps baited with two known tsetse fly management chemicals; a repellent blend derived from waterbuck odor, WRC (comprising geranylacetone, guaiacol, pentanoic acid and δ-octalactone), and an attractant comprising cow urine and acetone, in a series of Latin square-designed experiments. Coupled gas chromatography-electroantennographic detection (GC/EAD) and GC-mass spectrometry (GC/MS) analyses of zebra skin odors identified seven electrophysiologically-active components; 6-methyl-5-hepten-2-one, acetophenone, geranylacetone, heptanal, octanal, nonanal and decanal, which were tested in blends and singly for repellency to tsetse flies when combined with Ngu traps baited with cow urine and acetone in field trials. The crude zebra skin odors and a seven-component blend of the EAD-active components, formulated in their natural ratio of occurrence in zebra skin odor, significantly reduced catches of G . pallidipes by 66.7% and 48.9% respectively, and compared favorably with the repellency of WRC (58.1%– 59.2%). Repellency of the seven-component blend was attributed to the presence of the three ketones 6-methyl-5-hepten-2-one, acetophenone and geranylacetone, which when in a blend caused a 62.7% reduction in trap catch of G . pallidipes . Conclusions/Significance Our findings reveal fundamental insights into tsetse fly ecology and the allomonal effect of zebra skin odor, and potential integration of the three-component ketone blend into the management toolkit for tsetse and African trypanosomosis control.

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“…In this context, anti-disease strategies against African trypanosomiasis, in the broadest sense, may include: a) prevention of infection by breaking trypanosome transmission through avoiding contact with vectors by using odour-baited traps and screens to remove vectors from the vicinity of the host, 75 deploying synthetic or natural animal-derived vector repellents on the host 76,77 and/or elimination of vectors in the environment by aerial insecticide sprays [78][79][80][81] and integrated vector control using sterile insect technique; 82,83 97 considered, in a review, that anti-disease strategies could be targeted at treatments which did not eliminate the trypanosomes, but prevented the invasion of the brain by maintenance of blood brain barrier, neutralized the toxic products of trypanosomes, modulated the immune processes towards regulation of inflammation, reduction of effect of tumour necrosis factor, amplification of TGF-beta 1 and prevention of apoptosis of lymphocytes. Therefore, the anti-disease strategies propose to promote disease tolerance which is an ability of the host to limit the health consequences of the infective pathogen in spite of burden of infection.…”

Section: Anti-disease Strategies Against Trypanosomiasismentioning

confidence: 99%

Evolving anti-disease strategies from biochemical pathogenesis of african trypanosomiasis

Igbokwe¹

2018

ACP

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African trypanosomes are transmitted biologically by tsetse flies (Glossina spp) to humans and animals to cause African trypanosomiasis or trypanosomosis (sleeping sickness or Ngana). The pathology associated with the disease includes blood dyscrasia (anemia, leucopenia, thrombocytopenia), organ damage and inflammation. The infected host's metabolism is altered in response to the disease. The biochemical configuration and functions of the cell membrane, mitochondria, and cytosolic components are deranged by the infection. Cells of the infected host respond biochemically by producing chemical signals which regulate biochemical pathways, influence inflammatory responses and modify structural components. Several biochemical tools have been used to elucidate the biomolecules expressed in the disease. These biomolecules are also markers for diagnostic purposes and pathophysiological evaluations. The technologies involved in the biochemical studies are expanding from basic techniques of colorimetry, spectophotometry, and chromatography to sophisticated mass spectrometry. There are new trends employing systematics such as genomics, proteomics and metabolomics (metabonomics). The goal is to identify molecules and biochemical loci which can provide avenue for anti-disease strategies needed to treat and control the disease.

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Building Endogenous Capacity for the Management of Neglected Tropical Diseases in Africa: The Pioneering Role of ICIPE

Cited by 8 publications

References 28 publications

Seasonal Patterns: Bovine Trypanosomosis, Glossina pallidipes Density, and Infection in Rift Valleys of Gamo Zone, Southern Ethiopia

Seasonal Patterns: Bovine Trypanosomosis, Glossina pallidipes Density, and Infection in Rift Valleys of Gamo Zone, Southern Ethiopia

Zebra skin odor repels the savannah tsetse fly, Glossina pallidipes (Diptera: Glossinidae)

Evolving anti-disease strategies from biochemical pathogenesis of african trypanosomiasis

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