Distribution and trypanosome infection rates ofGlossina morsitans submorsitansNewst. along a trade cattle route in south-western Nigeria

1969 ◽  
Vol 58 (3) ◽  
pp. 537-548 ◽  
Author(s):  
D. A. T. Baldry
Keyword(s):  
Wide Distribution ◽  
Reliable Data ◽  
Tsetse Flies ◽  
Trypanosoma Vivax ◽  
Trypanosome Infection ◽  
Infection Rates ◽  
Wet Season ◽  
Glossina Morsitans ◽  
Glossina Morsitans Submorsitans ◽  
Open Woodland

The distribution and trypanosome infection rates ofGlossina morsitans submorsitansNewst. were studied during the wet season of 1967 along 75 miles of the main trade cattle route which passes through the savannah country between Ilorin and Oyo in south-western Nigeria.G.m. submorsitanswas found inhabiting open woodland, grassland, farmland and the environs of towns associated with the cattle route. In comparison with the types of habitat this species occupies in its zone of wide distribution in northern Nigeria, those habitats studied were considered atypical. It is suggested that the presence ofG.m. submorsitansin the area investigated had resulted from a southward population advance over the last 50 years and this hypothesis is discussed in relation to existing knowledge ofG.m. submorsitansadvances.The trypanosome infection rates of 61.6 and 76.6 per cent, found in 364 examples ofG.m. submorsitansdissected are much higher than previously recorded for any of the subspecies ofG. morsitansWestw. A steady southward increase in the trypanosome infection rates ofG.m. submorsitanswas demonstrated for populations inhabiting 200 miles of cattle route. Trypanosome infections inG.m. submorsitansare attributed toTrypanosoma vivaxandT. congolense, and the absence ofbrucei-group infections is discussed in relation to the incidence ofT. bruceiinfections in trade cattle and limitations of the technique used for demonstrating infections in tsetse flies.It is stressed that epizootiological aspects of the present findings cannot be clarified until reliable data on trypanosome infections of trade cattle in the area studied are available.

Suppression of Trypanosoma congolense, T. vivax and T. brucei infection rates in tsetse flies maintained on goats immunized with uncoated forms of trypanosomes grown in vitro

Parasitology ◽  
1985 ◽  
Vol 91 (1) ◽  
pp. 53-66 ◽  
Author(s):  
M. Murray ◽  
H. Hirumi ◽  
S. K. Moloo
Keyword(s):  
Binding Assay ◽  
Solid Phase ◽  
Antibody Responses ◽  
Tsetse Flies ◽  
Trypanosome Infection ◽  
Infection Rates ◽  
Glossina Morsitans ◽  
Glossina Morsitans Centralis ◽  
Species Specific

Significant suppression in the incidence of cyclical development of Trypanosonia congolense, T. vivax and T. brucei occurred in Glossina morsitans centralis maintained on goats immunized with in vitro-propagated uncoated forms of T. congolense, T. vivax and T. brucei, respectively. This was observed when tsetse given a T. congolense-infected feed were subsequently maintained on uninfected immunized goats and also when uninfected tsetse were fed on immunized goats infected with T. congolense, T. vivax and T. brucei. Suppression of infection rates in tsetse was trypanosome species specific, but was independent of the trypanosome stock used for immunization of goats. These findings were reflected in antibody responses to uncoated trypanosomes, as measured by immunofluorescence and the solid-phase immuno radiometric binding assay. Thus, antibody from goats immunized with uncoated trypano somes of one species exhibited minimal reactivity with uncoated forms of other species of trypanosomes, but showed high levels of activity with uncoated forms of the same or unrelated stocks of the same species. However, in view of the range of hosts upon which tsetse feed, it is open to question whether the use of a vaccine which suppresses trypanosome infection rates in tsetse would have any significant effect in the field.

Rickettsia-like organisms and chitinase production in relation to transmission of trypanosomes by tsetse flies

Parasitology ◽  
1993 ◽  
Vol 107 (2) ◽  
pp. 141-145 ◽  
Author(s):  
S. C. Welburn ◽  
K. Arnold ◽  
I. Maudlin ◽  
G. W. Gooday
Keyword(s):  
Glossina Morsitans Morsitans ◽  
Tsetse Flies ◽  
Trypanosome Infection ◽  
Infection Rates ◽  
Chitinolytic Activity ◽  
Trypanosoma Brucei Rhodesiense ◽  
Glossina Morsitans ◽  
High Incidence ◽  
Chitinase Production ◽  
Related Increase

SUMMARYRickettsia-like organisms (RLO) from tsetse midguts and mosquito cell cultures showed high levels of endochitinase activity. A line of Glossina morsitans morsitans highly susceptible to midgut trypanosome infection and with high incidence of RLO infection showed significantly greater chitinolytic activity than G. austeni which had low RLO incidence and were correspondingly refractory to midgut infection. Midgut infection rates of Trypanosoma brucei rhodesiense in G. m. morsitans showed a dose-related increase when flies were fed N-acetyl-D-glucosamine (GlcNAc) in the infective meal and for 4 subsequent days. A model is proposed for susceptibility to trypanosome infection based on the generation of GlcNAc by RLO endochitinase activity in tsetse pupae inhibiting midgut lectin in teneral flies.

The distribution of the tsetse flies Glossina morsitans submorsitans and G. palpalis gambiensis (Diptera: Glossinidae) in The Gambia and the application of survey results to tsetse and trypanosomiasis control

1993 ◽  
Vol 83 (4) ◽  
pp. 625-632 ◽  
Author(s):  
P. Rawlings ◽  
M.L. Ceesay ◽  
T.J. Wacher ◽  
W.F. Snow
Keyword(s):  
Environmental Factors ◽  
The Gambia ◽  
Control Measures ◽  
Evergreen Forest ◽  
General Distribution ◽  
Tsetse Flies ◽  
Glossina Morsitans ◽  
Glossina Morsitans Submorsitans ◽  
Survey Results ◽  
Riparian Habitats

AbstractA country-wide survey of the distribution of tsetse flies Glossina morsitans submorsitans Newstead and G. palpalis gambiensis Vanderplank was carried out in The Gambia, during 1989–1990, using box traps at 1654 sites over an area of 10,000 km2 The general distribution of tsetse had changed little during the last 45 years. G. m. submorsitans was present in dry, canopied woodland throughout most of the country, but was absent from an area south of the River Gambia stretching from the coast to some 100 km inland. G. p. gambiensis occurred in evergreen forest and woodland near the coast, and in riparian habitats along the length of the River Gambia and its major tributaries. Nowhere in the country was more than 20 km from tsetse-infested areas. Five major foci of G. m. submorsitans infestation were identified. Demographic, climatic and environmental factors affect tsetse populations in The Gambia, but it is expected that these foci of infestation will persist for at least the next 5–10 years. The numbers of tsetse trapped, expressed as relative densities, were used to assess the extent and severity of losses from trypanosomiasis to different categories of livestock. Survey results such as these could be used to assess whether control measures to reduce tsetse challenge are likely to be economically viable by using techniques such as insecticide-impregnated targets, pour-ons or chemotherapy.

scholarly journals Apparent density, trypanosome infection rates and host preference of tsetse flies in the sleeping sickness endemic focus of   Northwestern Uganda

2020 ◽  
Author(s):  
Robert Opiro ◽  
Robert Opoke ◽  
Harriet Angwech ◽  
Esther Nakafu ◽  
Francis A. Oloya ◽  
...  
Keyword(s):  
Infection Rate ◽  
Apparent Density ◽  
Blood Meal ◽  
Nested Pcr ◽  
Tsetse Fly ◽  
Tsetse Flies ◽  
Trypanosome Species ◽  
Trypanosome Infection ◽  
Infection Rates ◽  
Monitor Lizard

Abstract Background: African trypanosomiasis, caused by protozoa of the genus Trypanosoma and transmitted by the tsetse fly, is a serious parasitic disease of humans and animals. Reliable data on the vector distribution, feeding preference and the trypanosome species they carry is pertinent to planning sustainable control strategies.Methodology: We deployed 109 biconical traps in 10 villages in two districts of northwestern Uganda to obtain information on the apparent density, trypanosome infection rates and blood meal sources of tsetse flies. A subset (272) of the collected samples was analyzed for detection of trypanosomes species and sub-species using a nested PCR protocol based on primers amplifying the Internal Transcribed Spacer (ITS) region of ribosomal DNA. 34 blood-engorged adult tsetse midguts were analyzed for blood meal sources by sequencing of the mitochondrial cytochrome c oxidase 1 (COI) and cytochrome b (cytb) genes. Results: Out of the 109 traps deployed, we captured 622 Glossina fuscipes fuscipes tsetse flies (269 males and 353 females). Apparent density (AD) ranged from 0.6 to 3.7 flies/trap/day in the two districts. 29 (10.7%) of the flies were infected with one or more trypanosome species. Infection rate was not significantly associated with neither age group (χ2 = 5.001, df=2, 0.082), sex of the fly (χ2 = 0.099, df = 1, p = 0.753), district of origin (χ2= 0.629, df = 1, p = 0.428) nor village (χ2= 9.252, df = 9, p = 0.414). Nested PCR revealed several species of trypanosomes: T. vivax (6.62%), T. congolense (2.57%), T. brucei and T. simiae each at 0.73%. Blood meal analyses revealed five principal vertebrate hosts, namely, cattle (Bos taurus), humans (Homo sapiens), Nile monitor lizard (Varanus niloticus), African mud turtle (Pelusio schapini) and the African Savanna elephant (Loxodonta africana).Conclusion: We found an infection rate of 10.78 %, with all infections attributed to trypanosome species that are causative agents for the animal disease only. However, more verification of this finding using large-scale passive and active screening of human and tsetse samples should be done. Cattle and humans appear to be the most important tsetse hosts in the region and should be considered in the design of interventions.

scholarly journals Apparent Density, Trypanosome Infection Rates and Host Preference of Tsetse Flies in the Sleeping Sickness Endemic Focus of North-Western Uganda

2020 ◽  
Author(s):  
Robert Opiro ◽  
Robert Opoke ◽  
Harriet Angwech ◽  
Esther Nakafu ◽  
Francis A. Oloya ◽  
...  
Keyword(s):  
Infection Rate ◽  
Apparent Density ◽  
Blood Meal ◽  
Nested Pcr ◽  
Tsetse Fly ◽  
Tsetse Flies ◽  
Trypanosome Species ◽  
Trypanosome Infection ◽  
Infection Rates ◽  
Monitor Lizard

Abstract Background: African trypanosomiasis, caused by protozoa of the genus Trypanosoma and transmitted by the tsetse fly, is a serious parasitic disease of humans and animals. Reliable data on the vector distribution, feeding preference and the trypanosome species they carry is pertinent to planning sustainable control strategies.Methodology: We deployed 109 biconical traps in 10 villages in two districts of northwestern Uganda to obtain information on the apparent density, trypanosome infection rates and blood meal sources of tsetse flies. A subset of the collected samples was analyzed for detection of trypanosomes species and sub-species using a nested PCR protocol based on primers amplifying the Internal Transcribed Spacer (ITS) region of ribosomal DNA. 34 blood-engorged adult tsetse midguts were analyzed for blood meal sources by sequencing of the mitochondrial cytochrome c oxidase 1 (COI) and cytochrome b (cytb) genes. Results: Out of the 109 traps deployed, we captured 622 Glossina fuscipes fuscipes tsetse flies (269 males and 353 females). Apparent density (AD) ranged from 0.6 to 3.7 flies/trap/day in the two districts. 29 (10.7%) of the flies were infected with one or more trypanosome species, with infection rate significantly associated with age group (χ2 = 29.733, df = 2, p < 0.05) but not with sex (χ2 = 0.43, df = 1, p = 0.835) and district of origin (χ2 = 1.374, df = 1, p = 0.241). Nested PCR revealed several species of trypanosomes: T. vivax (62.1%), T. congolense (24.14 %), and T. brucei and T. simiae each at 6.89%. Blood meal analyses revealed five principal vertebrate hosts, namely, cattle (Bos taurus), humans (Homo sapiens), Nile monitor lizard (Varanus niloticus), African mud turtle (Pelusio schapini) and the African Savanna elephant (Loxodonta africana).Conclusion: We found a moderately high infection rate at 10.78%, with all infections attributed to trypanosome species that are causative agents for the animal disease only. However, more validation using large-scale passive and active screening of human and tsetse samples should be done. Cattle and humans appear to be the most important tsetse hosts in the region and should be considered in the design of interventions.

scholarly journals Apparent density, trypanosome infection rates and host preference of tsetse flies in the sleeping sickness endemic focus of Northwestern Uganda

2020 ◽  
Author(s):  
Robert Opiro ◽  
Robert Opoke ◽  
Harriet Angwech ◽  
Esther Nakafu ◽  
Francis A. Oloya ◽  
...  
Keyword(s):  
Infection Rate ◽  
Apparent Density ◽  
Blood Meal ◽  
Nested Pcr ◽  
Tsetse Fly ◽  
Tsetse Flies ◽  
Trypanosome Species ◽  
Trypanosome Infection ◽  
Infection Rates ◽  
Monitor Lizard

Abstract Background: African trypanosomiasis, caused by protozoa of the genus Trypanosoma and transmitted by the tsetse fly, is a serious parasitic disease of humans and animals. Reliable data on the vector distribution, feeding preference and the trypanosome species they carry is pertinent to planning sustainable control strategies.Methodology: We deployed 109 biconical traps in 10 villages in two districts of northwestern Uganda to obtain information on the apparent density, trypanosome infection rates and blood meal sources of tsetse flies. A subset (272) of the collected samples was analyzed for detection of trypanosomes species and sub-species using a nested PCR protocol based on primers amplifying the Internal Transcribed Spacer (ITS) region of ribosomal DNA. 34 blood-engorged adult tsetse midguts were analyzed for blood meal sources by sequencing of the mitochondrial cytochrome c oxidase 1 (COI) and cytochrome b (cytb) genes. Results: Out of the 109 traps deployed, we captured 622 Glossina fuscipes fuscipes tsetse flies (269 males and 353 females). Apparent density (AD) ranged from 0.6 to 3.7 flies/trap/day in the two districts. 29 (10.7%) of the flies were infected with one or more trypanosome species. Infection rate was not significantly associated with age group (χ2 = 5.001, df=2, p = 0.082), sex of the fly (χ2 = 0.099, df = 1, p = 0.753), district of origin (χ2= 0.629, df = 1, p = 0.428) and village of origin (χ2= 9.252, df = 9, p = 0.414). Nested PCR revealed several species of trypanosomes: T. vivax (6.62%), T. congolense (2.57%), T. brucei and T. simiae each at 0.73%. Blood meal analyses revealed five principal vertebrate hosts, namely, cattle (Bos taurus), humans (Homo sapiens), Nile monitor lizard (Varanus niloticus), African mud turtle (Pelusio schapini) and the African Savanna elephant (Loxodonta africana).Conclusion: We found an infection rate of 10.78 %, with all infections attributed to trypanosome species that are causative agents for the animal disease only. However, more verification of this finding using large-scale passive and active screening of human and tsetse samples should be done. Cattle and humans appear to be the most important tsetse hosts in the region and should be considered in the design of interventions.

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