Field evaluation of a dot-ELISA for the detection and differentiation of trypanosome species in infected tsetse flies (Glossinaspp.)

Parasitology ◽  
1996 ◽  
Vol 112 (2) ◽  
pp. 205-211 ◽  
Author(s):  
K. M. Bosompem ◽  
R. A. Masake ◽  
R. K. G. Assoku ◽  
E. A. Opiyo ◽  
V. M. Nantulya
Keyword(s):  
Salivary Gland ◽  
Salivary Glands ◽  
Infection Rate ◽  
Field Evaluation ◽  
Trypanosoma Congolense ◽  
Tsetse Flies ◽  
Trypanosome Species ◽  
Ambient Temperatures ◽  
Dot Elisa ◽  
Dissection Method

SummaryA rapid, visually read, dot-ELISA developed for the detection and differentiation of trypanosome species in tsetse flies (Glossinaspp.), was field tested alongside the standard fly dissection method on a ranch in south eastern Kenya. Of 104G. pallidipesdissected, 2 were found to be infected with trypanosomes in their midguts. By the dissection method the infecting trypanosome species could not be identified, as both flies had no salivary gland infections. However, using the dot-ELISA, the 2 flies were shown to be infected withTrypanosoma congolensein their midguts. The midguts of an additional 6 (5·8%) of the 104 G.pallidipestested positive forT. congolensein the dot-ELISA, even though no trypanosomes were seen on dissection. The infection rate for this fly species as determined using the dot-ELISA, therefore, was 7·7% forT. congolensein midgut infections compared to 1·9% identified by fly dissection. The salivary glands and mouthparts of the 6 additional tsetse flies identified by dot-ELISA were all negative as determined by the 2 techniques. None of 390 G.longipennisflies dissected and examined for trypanosomes in the midgut, salivary glands and mouthparts was shown, by this method, to be infected. Using the dot-ELISA, however, 17 (4·4%) of the flies tested positive forT. congolensein the midgut, whilst the salivary glands and mouthparts of the same flies were negative. Thus, the dot-ELISA appears to be more sensitive than the fly dissection method under field conditions. Moreover, the dot-ELISA can be performed in the field without electricity. It is simple to perform, and was not affected by high ambient temperatures (22–32°C), or by contamination of reactants with dust.

Trypanosome infections and survival in tsetse

Parasitology ◽  
1998 ◽  
Vol 116 (S1) ◽  
pp. S23-S28 ◽  
Author(s):  
I. Maudlin ◽  
S. C. Welburn ◽  
P. J. M. Milligan
Keyword(s):  
Salivary Gland ◽  
Salivary Glands ◽  
Trypanosoma Brucei ◽  
Glossina Morsitans Morsitans ◽  
Trypanosoma Congolense ◽  
Vectorial Capacity ◽  
Trypanosome Infection ◽  
Trypanosoma Brucei Rhodesiense ◽  
Glossina Morsitans ◽  
Differential Effects

SummaryThe effect of trypanosome infection on vector survival was observed in a line of Glossina morsitans morsitans selected for susceptibility to trypanosome infection. The differential effects of midgut and salivary gland infections on survival were examined by exposing flies to infection with either Trypanosoma congolense which colonizes midgut and mouthparts or Trypanosoma brucei rhodesiense which colonizes midgut and salivary glands. A comparison of the survival distributions of uninfected flies with those exposed to infection showed that salivary gland infection significantly reduces tsetse survival; midgut infection had little or no effect on the survival of tsetse. The significance of these findings is discussed in relation to the vectorial capacity of wild flies.

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 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 ◽  
Large Scale ◽  
Tsetse Fly ◽  
Tsetse Flies ◽  
Trypanosome Species ◽  
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, 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%), and 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 a moderately high infection rate of 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

2021 ◽  
Vol 17 (1) ◽  
Author(s):  
Robert Opiro ◽  
Robert Opoke ◽  
Harriet Angwech ◽  
Esther Nakafu ◽  
Francis A. Oloya ◽  
...  
Keyword(s):  
Infection Rate ◽  
Apparent Density ◽  
Blood Meal ◽  
Nested Pcr ◽  
Large Scale ◽  
Tsetse Fly ◽  
Tsetse Flies ◽  
Trypanosome Species ◽  
Trypanosome Infection ◽  
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 status 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 We captured a total of 622 Glossina fuscipes fuscipes tsetse flies (269 males and 353 females) in the two districts with apparent density (AD) ranging from 0.6 to 3.7 flies/trap/day (FTD). 10.7% (29/272) of the flies were infected with one or more trypanosome species. Infection rate was not significantly associated with district of origin (Generalized linear model (GLM), χ2 = 0.018, P = 0.895, df = 1, n = 272) and sex of the fly (χ2 = 1.723, P = 0.189, df = 1, n = 272). However, trypanosome infection was highly significantly associated with the fly’s age based on wing fray category (χ2 = 22.374, P < 0.001, df = 1, n = 272), being higher among the very old than the young tsetse. 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 (Pelusios chapini) and the African Savanna elephant (Loxodonta africana). Conclusion We found an infection rate of 10.8% in the tsetse sampled, with all infections attributed to trypanosome species that are causative agents for AAT. 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 control 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.

Detection and differentiation between trypanosome species in experimentally infected tsetse flies (Glossina spp.) using dot-ELISA

Acta Tropica ◽  
1995 ◽  
Vol 60 (2) ◽  
pp. 81-96 ◽  
Author(s):  
K.M. Bosompem ◽  
S.K. Moloo ◽  
R.K.G. Assoku ◽  
V.M. Nantulya
Keyword(s):  
Tsetse Flies ◽  
Trypanosome Species ◽  
Dot Elisa

Grouping of trypanosome species in mixed infections in Glossina pallidipes

Parasitology ◽  
2000 ◽  
Vol 120 (6) ◽  
pp. 583-592 ◽  
Author(s):  
M. J. LEHANE ◽  
A. R. MSANGI ◽  
C. J. WHITAKER ◽  
S. M. LEHANE
Keyword(s):  
Glossina Pallidipes ◽  
Trypanosoma Congolense ◽  
Tsetse Flies ◽  
Mixed Infections ◽  
Trypanosome Species ◽  
Infection Rates ◽  
Specific Primers ◽  
Tsetse Population ◽  
Chi Squared ◽  
Species Specific

Trypanosomes in the dissection-positive proboscis of Glossina pallidipes were identified by PCR using species-specific primers. Of the 3741 flies dissected 643 were proboscis positive. PCR was performed on 406 dissection-positive probosces giving positive identifications in 352 (86·7%) and infection rates of 14·8% for congolense-type infections, 2·8% for vivax- type infections and 1·4% for the unidentified group. Of the 352 PCR identified infections 225 were single, 111 were double, 13 were triple infections and there were 3 quadruple infections. Statistical analysis suggests that mixed infections group into 3 largely separate divisions among the tsetse population (i) Trypanosoma congolense savannah and T. congolense Kenya coast, (ii) T. simiae, T. congolense Tsavo and T. godfreyi and (iii) T. vivax. We conclude that either differing feeding patterns among members of the fly population or the ability of the trypanosomes in each of the infection categories to significantly influence the maturation of trypanosomes in the other categories are the most likely causes of the groupings noted. Chi-squared analysis of dissection and PCR methods of trypanosome identification revealed profound differences (χ = 19·1; D.F. = 1; P > 0·05). If confirmed in other studies these findings have serious implications for our understanding of trypanosome epidemiology in tsetse flies, much of which is founded on data from dissection-based trypanosome identifications.

Comparative sensitivity of dot-ELISA, PCR and dissection method for the detection of trypanosome infections in tsetse flies (Diptera: Glossinidae)

Acta Tropica ◽  
2000 ◽  
Vol 75 (3) ◽  
pp. 315-321 ◽  
Author(s):  
Johnson O Ouma ◽  
Rachael A Masake ◽  
Daniel K Masiga ◽  
Shamshudeen K Moloo ◽  
James T Njuguna ◽  
...  
Keyword(s):  
Tsetse Flies ◽  
Comparative Sensitivity ◽  
Dot Elisa ◽  
Dissection Method

scholarly journals Neurofibromin expression by normal salivary glands

2021 ◽  
Vol 17 (1) ◽  
Author(s):  
Eloá Borges Luna ◽  
Pâmella Pinho Montovani ◽  
Rafaela Elvira Rozza-de-Menezes ◽  
Karin Soares Cunha
Keyword(s):  
Salivary Gland ◽  
Salivary Glands ◽  
Acinar Cells ◽  
Staining Intensity ◽  
Neurofibromatosis 1 ◽  
Tissue Type ◽  
Sublingual Gland ◽  
Minor Salivary Glands ◽  
Expression Levels ◽  
Ductal Cells

AbstractIntroductionNeurofibromin, a protein encoded by theNF1gene, is mutated in neurofibromatosis 1, one of the most common genetic diseases. Oral manifestations are common and a high prevalence of hyposalivation was recently described in individuals with neurofibromatosis 1. Although neurofibromin is ubiquitously expressed, its expression levels vary depending on the tissue type and developmental stage of the organism. The role of neurofibromin in the development, morphology, and physiology of salivary glands is unknown and a detailed expression of neurofibromin in human normal salivary glands has never been investigated.AimTo investigate the expression levels and distribution of neurofibromin in acinar and ductal cells of major and minor salivary glands of adult individuals without NF1.Material and methodTen samples of morphologically normal major and minor salivary glands (three samples of each gland: parotid, submandibular and minor salivary; and one sample of sublingual gland) from individuals without neurofibromatosis 1 were selected to assess neurofibromin expression through immunohistochemistry. Immunoquantification was performed by a digital method.ResultsNeurofibromin was expressed in the cytoplasm of both serous and mucous acinar cells, as well as in ducts from all the samples of salivary glands. Staining intensity varied from mild to strong depending on the type of salivary gland and region (acini or ducts). Ducts had higher neurofibromin expression than acinar cells (p = 0.003). There was no statistical association between the expression of neurofibromin and the type of the salivary gland, considering acini (p = 0.09) or ducts (p = 0.50) of the four salivary glands (parotid, submandibular, minor salivary, and sublingual gland). Similar results were obtained comparing the acini (p = 0.35) and ducts (p = 0.50) of minor and major salivary glands. Besides, there was no correlation between the expression of neurofibromin and age (p = 0.08), and sex (p = 0.79) of the individuals, considering simultaneously the neurofibromin levels of acini and duct (n = 34).ConclusionNeurofibromin is expressed in the cytoplasm of serous and mucous acinar cells, and ductal cells of salivary glands, suggesting that this protein is important for salivary gland function.

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