scholarly journals A gene expression panel for estimating age in males and females of the sleeping sickness vector Glossina morsitans

2021 ◽  
Vol 15 (9) ◽  
pp. e0009797
Author(s):  
Eric R. Lucas ◽  
Alistair C. Darby ◽  
Stephen J. Torr ◽  
Martin J. Donnelly
Keyword(s):  
Gene Expression ◽  
Disease Transmission ◽  
Mean Squared Error ◽  
Glossina Morsitans Morsitans ◽  
Tsetse Flies ◽  
Glossina Morsitans ◽  
Vector Borne Diseases ◽  
Squared Error ◽  
Control Programmes ◽  
Vector Borne

Many vector-borne diseases are controlled by methods that kill the insect vectors responsible for disease transmission. Recording the age structure of vector populations provides information on mortality rates and vectorial capacity, and should form part of the detailed monitoring that occurs in the wake of control programmes, yet tools for obtaining estimates of individual age remain limited. We investigate the potential of using markers of gene expression to predict age in tsetse flies, which are the vectors of deadly and economically damaging African trypanosomiases. We use RNAseq to identify candidate expression markers, and test these markers using qPCR in laboratory-reared Glossina morsitans morsitans of known age. Measuring the expression of six genes was sufficient to obtain a prediction of age with root mean squared error of less than 8 days, while just two genes were sufficient to classify flies into age categories of ≤15 and >15 days old. Further testing of these markers in field-caught samples and in other species will determine the accuracy of these markers in the field.

scholarly journals A gene expression panel for estimating age in males and females of the sleeping sickness vector Glossina morsitans

2021 ◽  
Author(s):  
Eric R Lucas ◽  
Alistair C Darby ◽  
Stephen J Torr ◽  
Martin J Donnelly
Keyword(s):  
Gene Expression ◽  
Disease Transmission ◽  
Mean Squared Error ◽  
Tsetse Flies ◽  
Vector Borne Diseases ◽  
Squared Error ◽  
Form Part ◽  
Control Programmes ◽  
Vector Borne ◽  
Males And Females

Many vector-borne diseases are controlled by methods that kill the insect vectors responsible for disease transmission. Recording the age structure of vector populations provides information on mortality rates and vectorial capacity, and should form part of the detailed monitoring that occurs in the wake of control programmes, yet tools for obtaining estimates of individual age remain limited. We investigate the potential of using markers of gene expression to predict age in tsetse flies, which are the vectors of deadly and economically damaging African trypanosomiases. We use RNAseq to identify candidate expression markers, and test these markers using qPCR in laboratory-reared Glossina morstians morsitans of known age. Measuring the expression of six genes was sufficient to obtain a prediction of age with root mean squared error of less than 8 days, while just two genes were sufficient to classify flies into age categories of ≤15 and >15 days old. Further testing of these markers in field-caught samples and in other species will determine the accuracy of these markers in the field.

Turbulent plumes of heat, moist heat, and carbon dioxide elicit upwind anemotaxis in tsetse flies Glossina morsitans morsitans Westwood (Diptera: Glossinidae)

2002 ◽  
Vol 80 (7) ◽  
pp. 1149-1155 ◽  
Author(s):  
W G Evans ◽  
R H Gooding
Keyword(s):  
Carbon Dioxide ◽  
Wind Tunnel ◽  
Relative Humidity ◽  
Glossina Morsitans Morsitans ◽  
Tsetse Flies ◽  
Glossina Morsitans ◽  
Low Velocity ◽  
Upwind Flight ◽  
Moist Heat ◽  
Heated Air

The roles and interactions of turbulent plumes of heat, moist heat, and carbon dioxide in mediating upwind flight of adult tsetse flies (Glossina morsitans morsitans Westwood) were investigated using a wind tunnel in a constant-environment chamber. Heat fluctuations in the plume that were detected by a thermocouple and displayed as oscilloscope traces allowed direct visualization of the structures of the plumes. Significantly more flies flew upwind when exposed to plumes of (i) carbon dioxide (0.0051% above background) and air (58% relative humidity) compared with air alone; (ii) carbon dioxide and heated air (35% relative humidity and temperature fluctuating up to 0.09°C above background) compared with carbon dioxide and air; and (iii) carbon dioxide and moist (82% relative humidity) heated air (temperature fluctuating up to 0.05°C above background) compared with carbon dioxide and heated air. However, there were no significant differences in upwind flight of flies exposed to plumes of (i) air compared with humidified air (65% relative humidity); (ii) carbon dioxide and heated air compared with heated air alone; and (iii) carbon dioxide and moist heated air compared with moist heated air alone. Recorded temperature fluctuations in heat plumes transported downwind from a tethered steer in a pasture showed patterns similar to those produced in the wind-tunnel plumes. These results suggest that host emissions of carbon dioxide alone and combined heat and moisture carried downwind by low-velocity winds elicit upwind anemotaxis in tsetse flies, which distinguish these emissions from a background of lower atmospheric levels.

Responses of tsetse flies (Diptera: Glossinidae) to odour-baited trees

1991 ◽  
Vol 81 (3) ◽  
pp. 323-331 ◽  
Author(s):  
G. A. Vale
Keyword(s):  
Field Studies ◽  
Glossina Morsitans Morsitans ◽  
Tsetse Flies ◽  
Glossina Morsitans ◽  
Free Standing ◽  
Model Trees ◽  
Clear Effect

AbstractField studies in Zimbabwe elucidated how trees might be enhanced as baits for controlling Glossina morsitans morsitans Westwood and G. pallidipes Austen. Catches from electrocuting devices at the bases of trees were near nil when sampling tsetse flies landing on the trunk but much greater when sampling them flying within 1 m of the trunk. Catches increased 5–8 times when 2 m2 of the trunk were blackened and given odour of acetone, 1-octen-3-ol, 3-n-propyl phenol and 4-methyl phenol, but were still only ca. 30% of the catches from an odour-baited, free-standing, 1 × 1 m screen of black cloth. The upright trunk of real and model trees hindered their attractiveness but leaves and branches 5 m above ground had no clear effect. Real and artificial stumps of trees were as effective as the screen if they were 1 m2, compact and sharply outlined. The practical and biological implications of the results are discussed, with particular reference to the use of insecticide-treated netting with modified tree stumps as baits for control.

scholarly journals Population dynamics modelling : Impact of climate change on tick populations

2016 ◽  
Vol Volume 22 - 2016-2018 ◽  
Author(s):  
Leila Khouaja ◽  
Slimane Ben Miled ◽  
Hassan Hbid
Keyword(s):  
Climate Change ◽  
Disease Transmission ◽  
Physiological State ◽  
Good Prediction ◽  
Disease Evolution ◽  
Vector Borne Diseases ◽  
Host Interaction ◽  
Animaux Domestiques ◽  
Vector Borne ◽  
Dynamics Modelling

Epidemiology had an important development these last years allowing the resolution of a large number of problems and had good prediction on disease evolution. However, the transmission of several vector-borne diseases is closely connected to environmental protagonists, specially in the parasite-host interaction. Moreover, understanding the disease transmission is related to studying the ecology of all protagonists. These two levels of complexity(epidemiology and ecology) cannot be separated and have to be studied as a whole in a systematic way. Our goal is to understand the interaction of climate change on the evolution of a disease when the vector has ecological niche that depends on physiological state of development. We are particularly interested in tick vector diseases which are serious health problem affecting humans as well as domestic animals in many parts of the world. These infections are transmitted through a bite of an infected tick, and it appears that most of these infections are widely present in some wildlife species. L'épidémiologie a connu un développement important ces dernières années. Cette discipline a permis une meilleure compréhension del'évolution de maladies. Cependant, plusieurs maladies à transmission vectorielle sont étroitement liées aux protagonistes environnementaux. Ce constat est particulièrement vrai dans le contexte des interactions du parasite avec son hôte. De plus, comprendre la transmission de maladie est lié à l'étude de l'écologie de tous les protagonistes. Notre objectif est de comprendre l'influence du changement climatique sur l'évolution des maladies lorsque la niche écologique du vecteur dépend de l'état de développement physiologique de son hôte. Nous sommes particulièrement intéressés par les maladies vectorielles à tiques qui constituent un grave problème de santé touchant l'être humain et les animaux domestiques dans de nombreuses régions du monde. Ces infections sont généralement transmises par la piqûre d'une tique infectée et il apparaît que la plupart de ces infections sont largement présentées dans certaines espèces fauniques

Anterior midgut proteinase inhibitor from Glossina morsitans morsitans Westwood (Diptera: Glossinidae) and its effects upon tsetse digestive enzymes

1980 ◽  
Vol 58 (1) ◽  
pp. 79-87 ◽  
Author(s):  
Jon G. Houseman
Keyword(s):  
Proteinase Inhibitor ◽  
Periplaneta Americana ◽  
Specific Activity ◽  
Glossina Morsitans Morsitans ◽  
Tsetse Flies ◽  
Trypsin Activity ◽  
Glossina Morsitans ◽  
Trypsin Hydrolysis ◽  
Hydrolysis Of ◽  
Anterior Midgut

The anterior midgut of Glossina morsitans morsitans Westwood contains a proteinase inhibitor, molecular weight 5000 ± 2000daltons, stable to 1 M HCl, heat, and dialysis, but unstable to 1% trichloroacetic acid. Inhibitor activity is not associated with anticoagulant in the anterior midgut. The specific activity of the proteinase inhibitor is similar in mated and unmated females and greater than in male tsetse flies. Proteinase inhibitor inhibits proteinase VI and trypsin hydrolysis of N-benzoyl-L-arginine ethyl ester (BAEE) and benzoyl-DL-arginine-p-nitroanilide (BAPNA) but has no effect on proteinase VI hydrolysis of haemoglobin. Inhibition of trypsin hydrolysis of haemoglobin is noncompetitive. Proteinase inhibitor levels in the anterior midgut decreased immediately after feeding and then increased, reaching a maximum 60–100 h after ingestion of the bloodmeal. Postteneral flies contained higher levels of proteinase inhibitor than teneral individuals. Trypsin activity in gut homogenates of Phormia regina and Aedes aegypti was inhibited by the tsetse inhibitor. There was no detectable inhibition of bovine or Pterostichus adstrictus trypsin activity. Inhibition of Periplaneta americana trypsin occurred but was less than fly trypsin inhibition. The possible role of the inhibitor in terminating proteinase production is discussed.

scholarly journals Responses of Glossina pallidipes and Glossina morsitans morsitans tsetse flies to analogues of δ-octalactone and selected blends

Acta Tropica ◽  
2016 ◽  
Vol 160 ◽  
pp. 53-57 ◽  
Author(s):  
Benson M. Wachira ◽  
Paul O. Mireji ◽  
Sylvance Okoth ◽  
Margaret M. Ng’ang’a ◽  
Julius M. William ◽  
...  
Keyword(s):  
Glossina Pallidipes ◽  
Glossina Morsitans Morsitans ◽  
Tsetse Flies ◽  
Glossina Morsitans

Waterborne Diseases and Climate Change: Impact and Implications

2018 ◽  
pp. 469-484
Author(s):  
Maha Bouzid
Keyword(s):  
Climate Change ◽  
Developing Countries ◽  
Disease Transmission ◽  
Waterborne Diseases ◽  
Vector Borne Diseases ◽  
Significant Burden ◽  
Change Impact ◽  
Vector Borne ◽  
The Impact ◽  
Adaptation Options

Waterborne diseases are caused by a multitude of pathogens and associated with a significant burden in both developed and developing countries. While the assessment of the adverse impacts of climate change on human heath from infectious diseases has mainly focused on vector-borne diseases, waterborne diseases prevalence and transmission patterns are also likely to be impacted by environmental change. This chapter will outline relevant waterborne pathogens, summarise the impact of climate change on disease transmission and explore climate change adaptation options in order to reduce the increased burden of waterborne diseases.

Waterborne Diseases and Climate Change

2017 ◽  
pp. 1041-1055
Author(s):  
Maha Bouzid
Keyword(s):  
Climate Change ◽  
Developing Countries ◽  
Disease Transmission ◽  
Waterborne Diseases ◽  
Waterborne Pathogens ◽  
Vector Borne Diseases ◽  
Significant Burden ◽  
Vector Borne ◽  
The Impact ◽  
Adaptation Options

Waterborne diseases are caused by a multitude of pathogens and associated with a significant burden in both developed and developing countries. While the assessment of the adverse impacts of climate change on human heath from infectious diseases has mainly focused on vector-borne diseases, waterborne diseases prevalence and transmission patterns are also likely to be impacted by environmental change. This chapter will outline relevant waterborne pathogens, summarise the impact of climate change on disease transmission and explore climate change adaptation options in order to reduce the increased burden of waterborne diseases.

scholarly journals Mosquito diversity and dog heartworm prevalence in suburban areas

2020 ◽  
Vol 13 (1) ◽  
Author(s):  
Meredith R. Spence Beaulieu ◽  
Jennifer L. Federico ◽  
Michael H. Reiskind
Keyword(s):  
Disease Transmission ◽  
Disease Risk ◽  
Mosquito Species ◽  
Negative Relationship ◽  
Global Scale ◽  
Vector Borne Diseases ◽  
Suburban Areas ◽  
Host Seeking ◽  
Vector Borne ◽  
Wake County

Abstract Background Urbanization is occurring rapidly on a global scale and is altering mosquito communities, creating assemblages that are characteristically less diverse. Despite high rates of urbanization and ample examples of vector-borne diseases transmitted by multiple species, the effects of urbanization-driven mosquito diversity losses on disease transmission has not been well explored. We investigated this question using the dog heartworm, a filarial parasite vectored by numerous mosquito species. Methods We trapped host-seeking mosquitoes in undeveloped areas and neighborhoods of different ages in Wake County, North Carolina, USA, analyzing captured mosquitoes for heartworm DNA. We compared within-mosquito heartworm infection across land-use types by Kruskal–Wallis and likelihood ratio tests. Using zip code level data acquired from dogs in a local shelter, we performed linear regressions of within-host heartworm prevalence by within-mosquito heartworm prevalence as well as by three mosquito diversity measures. We also determined the best predictor of host-level prevalence among models including within-mosquito infection, mosquito diversity and abundance, and socioeconomic status as variables. Results Suburban areas had lower within-mosquito heartworm prevalence and lower likelihood of heartworm-positive mosquitoes than did undeveloped field sites, although no differences were seen between suburban and undeveloped wooded sites. No relationships were noted between within-mosquito and within-host heartworm prevalence. However, mosquito diversity metrics were positively correlated with host heartworm prevalence. Model selection revealed within-host prevalence was best predicted by a positive relationship with mosquito Shannon–Wiener diversity and a negative relationship with household income. Conclusions Our results demonstrate that decreases in mosquito diversity due to urbanization alter vector-borne disease risk. With regard to dog heartworm disease, this loss of mosquito diversity is associated with decreased heartworm prevalence within both the vector and the host. Although the response is likely different for diseases transmitted by one or few species, mosquito diversity losses leading to decreased transmission could be generalizable to other pathogens with multiple vectors. This study contributes to better understanding of the effects of urbanization and the role of vector diversity in multi-vectored pathosystems.

The olfactory responses of tsetse flies, Glossina spp. (Diptera: Glossinidae), to phenols and urine in the field

1988 ◽  
Vol 78 (2) ◽  
pp. 293-300 ◽  
Author(s):  
G. A. Vale ◽  
D. R. Hall ◽  
A. J. E. Gough
Keyword(s):  
Glossina Morsitans Morsitans ◽  
Synthetic Mixture ◽  
Tsetse Flies ◽  
Glossina Morsitans ◽  
Olfactory Responses ◽  
Naturally Occurring

AbstractIn Zimbabwe, catches of Glossina morsitans morsitans Westwood and G. pallidipes Austen in traps baited with acetone and 1-octen-3-ol were increased by the addition of the synthetic mixture of eight phenols found in cattle urine to a level equal to or greater than those with natural urine. The addition of natural urine to the synthetic mixture did not increase catches further, indicating that the phenols account for essentially all the attractiveness of cattle urine. 4-Methylphenol and 3-n-propylphenol were shown to be the naturally-occurring components essential for attractiveness, and 2-methoxyphenol was found to reduce attractiveness. 4-Methylphenol alone was slightly attractive to both species, but only for males, increasing catches by approximately 30%. Catches of both species were increased by approximately 50% by 3-n-propylphenol. The addition of 4-methylphenol increased catches of G. pallidipes by up to a further four times, but catches of G. m. morsitans were decreased. Of 14 other phenols tested, phenol, 3-methylphenol and 4-ethylphenol increased the attractiveness of 3-n-propylphenol to G. pallidipes without decreasing the attractiveness to G. m. morsitans; (E)- and (Z)-3-(1-propenyl)phenol, potential contaminants in 3-n- propylphenol, did not reduce the attractiveness of mixtures of 3-n-propylphenol and 4-methylphenol, and the E and, to a lesser extent, the Z isomer could substitute for 3-n-pro-pylphenol in these mixtures. Mixtures of phenols which increased the attractiveness of traps to tsetse showed similar effects with targets but at a slightly reduced level.

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