NewTrypanosoma (Duttonella) vivaxgenotypes from tsetse flies in East Africa

Parasitology ◽  
2009 ◽  
Vol 137 (4) ◽  
pp. 641-650 ◽  
Author(s):  
E. R. ADAMS ◽  
P. B. HAMILTON ◽  
A. C. RODRIGUES ◽  
I. I. MALELE ◽  
V. DELESPAUX ◽  
...  
Keyword(s):  
East Africa ◽  
Glossina Pallidipes ◽  
Mammalian Host ◽  
Tsetse Flies ◽  
South American ◽  
Full Diversity ◽  
Dehydrogenase Gene ◽  
Multiple Regions ◽  
Animal Trypanosomiasis ◽  
And Control

SUMMARYSalivarian trypanosomes pose a substantial threat to livestock, but their full diversity is not known. To survey trypanosomes carried by tsetse in Tanzania, DNA samples from infected proboscides ofGlossina pallidipesandG. swynnertoniwere identified using fluorescent fragment length barcoding (FFLB), which discriminates species by size polymorphisms in multiple regions of the ribosomal RNA locus. FFLB identified the trypanosomes in 65 of 105 (61·9%) infected proboscides, revealing 9 mixed infections. Of 7 different FFLB profiles, 2 were similar but not identical to reference West AfricanTrypanosoma vivax; 5 other profiles belonged to known species also identified in fly midguts. Phylogenetic analysis of the glycosomal glyceraldehyde phosphate dehydrogenase gene revealed that the TanzanianT. vivaxsamples fell into 2 distinct groups, both outside the main clade of African and South AmericanT. vivax. These newT. vivaxgenotypes were common and widespread in tsetse in Tanzania. TheT. brucei-like trypanosome previously described from tsetse midguts was also found in 2 proboscides, demonstrating a salivarian transmission route. Investigation of mammalian host range and pathogenicity will reveal the importance of these new trypanosomes for the epidemiology and control of animal trypanosomiasis in East Africa.

Escape mechanisms of African trypanosomes: why trypanosomosis is keeping us awake

Parasitology ◽  
2014 ◽  
Vol 142 (3) ◽  
pp. 417-427 ◽  
Author(s):  
JENNIFER CNOPS ◽  
STEFAN MAGEZ ◽  
CARL De TREZ
Keyword(s):  
Immune Response ◽  
Trypanosoma Brucei ◽  
Parasitic Infection ◽  
Mammalian Host ◽  
Tsetse Flies ◽  
African Trypanosomes ◽  
Transmission Potential ◽  
Highly Sensitive ◽  
Commercially Important ◽  
And Control

SUMMARYAfrican trypanosomes have been around for more than 100 million years, and have adapted to survival in a very wide host range. While various indigenous African mammalian host species display a tolerant phenotype towards this parasitic infection, and hence serve as perpetual reservoirs, many commercially important livestock species are highly disease susceptible. When considering humans, they too display a highly sensitive disease progression phenotype for infections withTrypanosoma brucei rhodesienseorTrypanosoma brucei gambiense, while being intrinsically resistant to infections with other trypanosome species. As extracellular trypanosomes proliferate and live freely in the bloodstream and lymphatics, they are constantly exposed to the immune system. Due to co-evolution, this environment however no longer poses a hostile threat, but has become the niche environment where trypanosomes thrive and obligatory await transmission through the bites of tsetse flies or other haematophagic vectors, ideally without causing severe side infection-associated pathology to their host. Hence, African trypanosomes have acquired various mechanisms to manipulate and control the host immune response, evading effective elimination. Despite the extensive research into trypanosomosis over the past 40 years, many aspects of the anti-parasite immune response remain to be solved and no vaccine is currently available. Here we review the recent work on the different escape mechanisms employed by African Trypanosomes to ensure infection chronicity and transmission potential.

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

2020 ◽  
Author(s):  
Mallion Kangume ◽  
Denis Muhangi ◽  
Joseph Byaruhanga ◽  
Aggrey Agaba ◽  
Joachim Sserunkuma ◽  
...  
Keyword(s):  
Mixed Infection ◽  
National Park ◽  
Glossina Pallidipes ◽  
Tsetse Fly ◽  
Sub Saharan Africa ◽  
Public Health Importance ◽  
Baseline Information ◽  
Sub Saharan ◽  
Animal Trypanosomiasis ◽  
And Control

Abstract Background African Animal Trypanosomiasis (AAT) is an infectious disease of economic and public health importance hindering agricultural productivity in Sub-Saharan Africa. The current study aimed at providing baseline information on tsetse fly distribution and occurrence of Trypanosoma species in cattle and goats within and around Queen Elizabeth National Park (QENP), in western Uganda. A minimal entomological survey was conducted in April 2017 while blood samples collected from cattle (n = 576) and goats (n = 319) in June 2015 and May 2017 were subjected to microscopy and Polymerase Chain Reaction (PCR) to determine the occurrence of trypanosome species. Results Glossina pallidipes and G. fuscipes were the only tsetse fly species trapped in the study area with apparent density of 20.6. The overall prevalence of Trypanosoma spp. in cattle and goats was 38.9% and 37% respectively for samples collected in 2015 while the prevalence of Trypanosome spp in cattle samples collected in 2017 was 38%. In 2015, T. brucei was the highest prevalent trypanosome in both cattle (23%) and goats (18.8%). In both cattle and goats, a mixed infection of T. brucei + T. congolense was most encountered with prevalence of 4.8% and 4.1% in cattle and goats, respectively. In goats a mixed infection of T. brucei + T. congolense + T. vivax was higher (2.8%) than in cattle (2.4%). In 2017, in cattle (n = 250), the prevalence for T. congolense was 32.4%, T. vivax was 6.8% and T. brucei was 6.4%. A co-infection of T. brucei and T. congolense was most prevalent (7.4%). Only 3.2% of the cattle were co-infected with all the three Trypanosome species. Conclusions Current findings show that there are two types of Tsetse fly specie, s important in transmission of AAT. Presence of these parasites in goats shows that they also play a key role in epidemiology of the disease and control efforts should aim also involve goat farmers.

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

2020 ◽  
Author(s):  
Mallion Kangume ◽  
Denis Muhangi ◽  
Joseph Byaruhanga ◽  
Aggrey Agaba ◽  
Joachim Sserunkuma ◽  
...  
Keyword(s):  
National Park ◽  
Glossina Pallidipes ◽  
Dual Infection ◽  
Tsetse Fly ◽  
Sub Saharan Africa ◽  
Tsetse Flies ◽  
Baseline Information ◽  
Veterinary Importance ◽  
Sub Saharan ◽  
Animal Trypanosomiasis

Abstract Background: African Animal Trypanosomiasis (AAT) is an infectious disease of economic and veterinary importance in Sub-Saharan Africa. The current study aimed at providing baseline information on tsetse fly distribution and occurrence of Trypanosoma species in cattle and goats within and around Queen Elizabeth National Park (QENP), in western Uganda. A minimal entomological survey was conducted in April 2017 while blood samples collected from cattle (n = 576) and goats (n = 319) in June 2015 and May 2017 were subjected to Polymerase Chain Reaction (PCR) to determine the occurrence of Trypanosoma species.Results: Glossina pallidipes and G. fuscipes were the only tsetse fly species trapped in the study area with apparent density of 20.6. The overall prevalence of Trypanosoma spp. was 27% for goats and approximately 38% for cattle. The most prevalent Trypanosoma spp. in goats was T. brucei (n = 60, 18.8%) while the most prevalent in cattle was T. congolense (n = 102, 27.1%). In both cattle and goats, a dual infection of T. brucei + T. congolense was most encountered. In goats a triple infection of T. brucei + T. congolense + T. vivax was higher than that in cattle. Conclusions: Current findings show that there are two species of tsetse flies, and three species of Trypanosoma, important in transmission of AAT in both cattle and goats. Control efforts of AAT have mainly focused on cattle and this study proves that prevention and control efforts should also involve goat farmers.

scholarly journals An update on the distribution of Glossina (tsetse flies) at the wildlife-human-livestock interface of Akagera National Park, Rwanda

2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Richard S. Gashururu ◽  
Samuel M. Githigia ◽  
Methode N. Gasana ◽  
Richard Habimana ◽  
Ndichu Maingi ◽  
...  
Keyword(s):  
National Park ◽  
Control Strategies ◽  
Glossina Pallidipes ◽  
Distribution Patterns ◽  
Tsetse Flies ◽  
Wet Season ◽  
Chi Square ◽  
Large Numbers ◽  
Surrounding Areas ◽  
Biconical Traps

Abstract Background Glossina (tsetse flies) biologically transmit trypanosomes that infect both humans and animals. Knowledge of their distribution patterns is a key element to better understand the transmission dynamics of trypanosomosis. Tsetse distribution in Rwanda has not been well enough documented, and little is known on their current distribution. This study determined the current spatial distribution, abundance, diversity, and seasonal variations of tsetse flies in and around the Akagera National Park. Methods A longitudinal stratified sampling following the seasons was used. Biconical traps were deployed in 55 sites for 6 consecutive days of each study month from May 2018 to June 2019 and emptied every 48 h. Flies were identified using FAO keys, and the number of flies per trap day (FTD) was used to determine the apparent density. Pearson chi-square (χ2) and parametrical tests (t-test and ANOVA) were used to determine the variations between the variables. The significance (p < 0.05) at 95% confidence interval was considered. Logistic regression was used to determine the association between tsetse occurrence and the associated predictors. Results A total of 39,516 tsetse flies were collected, of which 73.4 and 26.6% were from inside Akagera NP and the interface area, respectively. Female flies accounted for 61.3 while 38.7% were males. Two species were identified, i.e. G. pallidipes [n = 29,121, 7.4 flies/trap/day (FTD)] and G. morsitans centralis (n = 10,395; 2.6 FTD). The statistical difference in numbers was significant between the two species (p = 0.000). The flies were more abundant during the wet season (15.8 FTD) than the dry season (4.2 FTD). Large numbers of flies were trapped around the swamp areas (69.1 FTD) inside the park and in Nyagatare District (11.2 FTD) at the interface. Glossina morsitans was 0.218 times less likely to occur outside the park. The chance of co-existing between the two species reduced outside the protected area (0.021 times). Conclusions The occurrence of Glossina seems to be limited to the protected Akagera NP and a narrow band of its surrounding areas. This finding will be crucial to design appropriate control strategies. Glossina pallidipes was found in higher numbers and therefore is conceivably the most important vector of trypanosomosis. Regional coordinated control and regular monitoring of Glossina distribution are recommended. Graphic Abstract

Aircraft Applications of Insecticides in East Africa. IV.—The Application of Coarse Aerosols in Savannah Woodland containing the Tsetse Flies Glossina morsitans and G. swynnertoni

1953 ◽  
Vol 44 (4) ◽  
pp. 627-640 ◽  
Author(s):  
K. S. Hocking ◽  
H. C. M. Parr ◽  
D. Yeo ◽  
D. Anstey
Keyword(s):  
East Africa ◽  
Meteorological Conditions ◽  
The Other ◽  
Tsetse Flies ◽  
Small Populations ◽  
Central Province ◽  
Glossina Morsitans ◽  
Short Period ◽  
Savannah Woodland ◽  
Mass Median

Attempts have been made to eradicate the tsetse flies G. morsitans and G. swynnertoni from two blocks of savannah woodland situated in the Central Province of Tanganyika.The insecticides were applied from aircraft. Coarse aerosols were used, with mass median diameters of approximately 90 microns; droplet diameters varied from 4 microns to 250 microns approximately.Eight applications of insecticides were made at intervals of two weeks. Each application was carried out at a nominal dosage of 0·25 gallons per acre, which was equivalent to 0·20 1b. per acre of the p, p'isomer of DDT or 0·03 lb. per acre of the γ isomer of BHC.In the area treated with DDT it is possible that both species of flies were eradicated for a short period, but small populations were re-established there by immigrant flies. In the other block the reduction was not so great, but it is not considered that this was due to a lesser effectiveness of the BHC, but to a combination of circumstances that led to less effective applications.Some general observations are made upon the use of aircraft for this sort of work, particularly in connection with the effect of meteorological conditions.

scholarly journals Comparative performance of traps in catching tsetse flies (Diptera: Glossinidae) in Tanzania

2016 ◽  
Vol 83 (1) ◽  
Author(s):  
Imna I. Malele ◽  
Johnson O. Ouma ◽  
Hamisi S. Nyingilili ◽  
Winston A. Kitwika ◽  
Deusdedit J. Malulu ◽  
...  
Keyword(s):  
Glossina Pallidipes ◽  
Abundant Species ◽  
Tsetse Fly ◽  
Tsetse Flies ◽  
Comparative Performance ◽  
Control Programmes ◽  
Fly Control ◽  
Tsetse Fly Control ◽  
Species Being ◽  
Biconical Traps

This study was conducted to determine the efficiency of different tsetse traps in 28 sites across Tanzania. The traps used were biconical, H, NGU, NZI, pyramidal, S3, mobile, and sticky panels. Stationary traps were deployed at a distance of 200 m apart and examined 72 h after deployment. The results showed that 117 (52.2%) out of the 224 traps deployed captured at least one Glossina species. A total of five Glossina species were captured, namely Glossina brevipalpis, Glossina pallidipes, Glossina swynnertoni, Glossina morsitans, and Glossina fuscipes martinii. Biconical traps caught tsetse flies in 27 sites, pyramidal in 26, sticky panel in 20, mobile in 19, S3 in 15, NGU in 7, H in 2 and NZI in 1. A total of 21 107 tsetse flies were trapped, with the most abundant species being G. swynnertoni (55.9%), followed by G. pallidipes (31.1%), G. fuscipes martinii (6.9%) and G. morsitans (6.0%). The least caught was G. brevipalpis (0.2%). The highest number of flies were caught by NGU traps (32.5%), followed by sticky panel (16%), mobile (15.4%), pyramidal (13.0%), biconical (11.3%) and S3 (10.2%). NZI traps managed to catch 0.9% of the total flies and H traps 0.7%. From this study, it can be concluded that the most efficient trap was NGU, followed by sticky panel and mobile, in that order. Therefore, for tsetse fly control programmes, NGU traps could be the better choice. Conversely, of the stationary traps, pyramidal and biconical traps captured tsetse flies in the majority of sites, covering all three ecosystems better than any other traps; therefore, they would be suitable for scouting for tsetse infestation in any given area, thus sparing the costs of making traps for each specific Glossina species.Keywords: tseste; traps; densties; Glossina; mobile; stationary; Tanzania

Aircraft Applications of Insecticides in East Africa. VI.—Applications of a coarse Aerosol containning DDT to control the Tsetse Flies, Glossina morsitans Westw., Glossina swynnertoni Aust. and Glossina pallidipes Aust.

1954 ◽  
Vol 45 (3) ◽  
pp. 585-603 ◽  
Author(s):  
K. S. Hocking ◽  
D. Yeo ◽  
D. G. Anstey
Keyword(s):  
Random Effects ◽  
Glossina Pallidipes ◽  
Tsetse Flies ◽  
Glossina Morsitans ◽  
Median Diameter ◽  
Coarse Aerosol ◽  
Savannah Woodland ◽  
Mass Median ◽  
Glossina Swynnertoni ◽  
Mass Median Diameter

An experiment is described where applications of a coarse aerosol were made to savannah woodland containing the tsetse flies, Glossina moritans Westw., G. swynnertoni Aust. and G. pallidipes Aust.Seven applications were made, each at a nominal dosage of 0·25 lb. of technical DDT per acre and 0·25 gallons of solution per acre. The applications in any particular part of the treaed woodland covered an interval of 90 days, or rather more than two pupal periods.The coarse aerosol was produced by emitting the insecticidal solution under pressure through fine nozzles fitted to a boom. It had a mass median diameter of approximately 60 microns, and droplet dismeters varied from a few microns to approximately 200 microns.The population of G. pallidipes was so drastically reduced that it has subsequently dies out. The reduction of G. morsitans was approximately 95 per cent. The differences between the reductions are attributed mainly to differences between the ease with which the three species can be killed. It is pointed out that this is not necessarily equivalent to differences in susceptibility.Comparisons are made with previous experiments, and the different results of the various experiments are difficult to explian satisfactory. The increased cover in savannah areas during the leafy period may have reduced the effectiveness of the applications, and the total periods covered by the various series of applications were probably also important. Random effects, leading to ineffective treatments, may also be important.Costs are discussed.

scholarly journals Differential virulence and tsetse fly transmissibility of Trypanosoma congolense and Trypanosoma brucei strains

2017 ◽  
Vol 84 (1) ◽  
Author(s):  
Purity K. Gitonga ◽  
Kariuki Ndung’u ◽  
Grace A. Murilla ◽  
Paul C. Thande ◽  
Florence N. Wamwiri ◽  
...  
Keyword(s):  
Survival Time ◽  
Trypanosoma Brucei ◽  
Acute Infection ◽  
Glossina Pallidipes ◽  
Trypanosoma Congolense ◽  
Tsetse Fly ◽  
Economic Losses ◽  
Entire Group ◽  
Tsetse Flies ◽  
African Countries

African animal trypanosomiasis causes significant economic losses in sub-Saharan African countries because of livestock mortalities and reduced productivity. Trypanosomes, the causative agents, are transmitted by tsetse flies (Glossina spp.). In the current study, we compared and contrasted the virulence characteristics of five Trypanosoma congolense and Trypanosoma brucei isolates using groups of Swiss white mice (n = 6). We further determined the vectorial capacity of Glossina pallidipes, for each of the trypanosome isolates. Results showed that the overall pre-patent (PP) periods were 8.4 ± 0.9 (range, 4–11) and 4.5 ± 0.2 (range, 4–6) for T. congolense and T. brucei isolates, respectively (p < 0.01). Despite the longer mean PP, T. congolense–infected mice exhibited a significantly (p < 0.05) shorter survival time than T. brucei–infected mice, indicating greater virulence. Differences were also noted among the individual isolates with T. congolense KETRI 2909 causing the most acute infection of the entire group with a mean ± standard error survival time of 9 ± 2.1 days. Survival time of infected tsetse flies and the proportion with mature infections at 30 days post-exposure to the infective blood meals varied among isolates, with subacute infection–causing T. congolense EATRO 1829 and chronic infection–causing T. brucei EATRO 2267 isolates showing the highest mature infection rates of 38.5% and 23.1%, respectively. Therefore, our study provides further evidence of occurrence of differences in virulence and transmissibility of eastern African trypanosome strains and has identified two, T. congolense EATRO 1829 and T. brucei EATRO 2267, as suitable for tsetse infectivity and transmissibility experiments.

scholarly journals History of Sleeping Sickness in East Africa

1999 ◽  
Vol 12 (1) ◽  
pp. 112-125 ◽  
Author(s):  
Geoff Hide
Keyword(s):  
East Africa ◽  
Molecular Data ◽  
Sleeping Sickness ◽  
Tsetse Fly ◽  
Tsetse Flies ◽  
Agricultural Practice ◽  
Molecular Approaches ◽  
History Of ◽  
The Stability ◽  
The Right

SUMMARY The history of human sleeping sickness in East Africa is characterized by the appearance of disease epidemics interspersed by long periods of endemicity. Despite the presence of the tsetse fly in large areas of East Africa, these epidemics tend to occur multiply in specific regions or foci rather than spreading over vast areas. Many theories have been proposed to explain this phenomenon, but recent molecular approaches and detailed analyses of epidemics have highlighted the stability of human-infective trypanosome strains within these foci. The new molecular data, taken alongside the history and biology of human sleeping sickness, are beginning to highlight the important factors involved in the generation of epidemics. Specific, human-infective trypanosome strains may be associated with each focus, which, in the presence of the right conditions, can be responsible for the generation of an epidemic. Changes in agricultural practice, favoring the presence of tsetse flies, and the important contribution of domestic animals as a reservoir for the parasite are key factors in the maintenance of such epidemics. This review examines the contribution of molecular and genetic data to our understanding of the epidemiology and history of human sleeping sickness in East Africa.

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