Host and Pathogen Coexistence in Sexually Transmitted and Vector-Borne Diseases Characterized by Frequency-Dependent Disease Transmission

1993 ◽  
Vol 142 (3) ◽  
pp. 543-552 ◽  
Author(s):  
Peter H. Thrall ◽  
Janis Antonovics ◽  
David W. Hall
Keyword(s):  
Disease Transmission ◽  
Frequency Dependent ◽  
Sexually Transmitted ◽  
Vector Borne Diseases ◽  
Vector Borne

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

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.

scholarly journals Climate, environmental and socio-economic change: weighing up the balance in vector-borne disease transmission

2015 ◽  
Vol 370 (1665) ◽  
pp. 20130551 ◽  
Author(s):  
Paul E. Parham ◽  
Joanna Waldock ◽  
George K. Christophides ◽  
Deborah Hemming ◽  
Folashade Agusto ◽  
...  
Keyword(s):  
Climate Change ◽  
Disease Transmission ◽  
Disease Burden ◽  
Current Knowledge ◽  
Vector Borne Diseases ◽  
Data Limitations ◽  
Vector Borne ◽  
Research Questions ◽  
Potential Impact ◽  
Socio Economic Factors

Arguably one of the most important effects of climate change is the potential impact on human health. While this is likely to take many forms, the implications for future transmission of vector-borne diseases (VBDs), given their ongoing contribution to global disease burden, are both extremely important and highly uncertain. In part, this is owing not only to data limitations and methodological challenges when integrating climate-driven VBD models and climate change projections, but also, perhaps most crucially, to the multitude of epidemiological, ecological and socio-economic factors that drive VBD transmission, and this complexity has generated considerable debate over the past 10–15 years. In this review, we seek to elucidate current knowledge around this topic, identify key themes and uncertainties, evaluate ongoing challenges and open research questions and, crucially, offer some solutions for the field. Although many of these challenges are ubiquitous across multiple VBDs, more specific issues also arise in different vector–pathogen systems.

scholarly journals Are Temperature Suitability and Socioeconomic Factors Reliable Predictors of Dengue Transmission in Brazil?

2021 ◽  
Vol 2 ◽  
Author(s):  
Lorena M. Simon ◽  
Thiago F. Rangel
Keyword(s):  
Socioeconomic Factors ◽  
Disease Transmission ◽  
Effect Of Temperature ◽  
Relative Role ◽  
Transmission Potential ◽  
Vector Borne Diseases ◽  
Dengue Transmission ◽  
Significant Proxy ◽  
Vector Borne ◽  
Temperature Suitability

Dengue is an ongoing problem, especially in tropical countries. Like many other vector-borne diseases, the spread of dengue is driven by a myriad of climate and socioeconomic factors. Within developing countries, heterogeneities on socioeconomic factors are expected to create variable conditions for dengue transmission. However, the relative role of socioeconomic characteristics and their association with climate in determining dengue prevalence are poorly understood. Here we assembled essential socioeconomic factors over 5570 municipalities across Brazil and assessed their effect on dengue prevalence jointly with a previously predicted temperature suitability for transmission. Using a simultaneous autoregressive approach (SAR), we showed that the variability in the prevalence of dengue cases across Brazil is primarily explained by the combined effect of climate and socioeconomic factors. At some dengue seasons, the effect of temperature on transmission potential showed to be a more significant proxy of dengue cases. Still, socioeconomic factors explained the later increase in dengue prevalence over Brazil. In a heterogeneous country such as Brazil, recognizing the transmission drivers by vectors is a fundamental issue in effectively predicting and combating tropical diseases like dengue. Ultimately, it indicates that not considering socioeconomic factors in disease transmission predictions might compromise efficient surveillance strategies. Our study shows that sanitation, urbanization, and GDP are regional indicators that should be considered along with temperature suitability on dengue transmission, setting effective directions to mosquito-borne disease control.

scholarly journals Vectors and vector-borne diseases in Qatar: current status, key challenges and future prospects

2021 ◽  
pp. 1-12
Author(s):  
F. Schaffner ◽  
D. Bansal ◽  
K. Mardini ◽  
S.A. Al-Marri ◽  
M.H.J. Al-Thani ◽  
...  
Keyword(s):  
Public Health ◽  
Vector Control ◽  
Disease Transmission ◽  
Eastern Mediterranean ◽  
Current Status ◽  
Global Public Health ◽  
Future Prospects ◽  
Vector Borne Diseases ◽  
Sustainable Solutions ◽  
Vector Borne

Vector-borne diseases (VBDs) have re-emerged worldwide due to urbanisation, increase in travel and climate change, becoming a major and serious threat to global public health. In Qatar, the concern has recently risen because of the attribution of the soccer 2022 FIFA World Cup Qatar™, which necessitates fulfilling requirements in terms of prevention and preparedness for disease transmission, including VBDs. This review presents a general overview about current status of vectors and VBDs in Qatar and addresses key challenges and future prospects of control programmes and strategies. It is based on a vector control situation analysis and needs assessment performed during an expert mission in Qatar, November 2017, organised by the WHO Eastern Mediterranean Regional Office and achieved in collaboration with the Ministry of Public Health of Qatar and other local stakeholders. The situation of vectors and VBDs of public health importance in Qatar was analysed based on a systematic literature review by December 31, 2019. The literature reveals that no locally transmitted VBD cases have been recorded in Qatar, but cases were recorded among expatriate workers and travellers who returned from an endemic country. However, data on VBD cases remain scarce except for malaria. The presence of native arthropod vectors is under-recorded to date. A compilation of literature data revealed reports of 30 vector species, including 20 mosquitoes, 2 fleas, 1 louse, 1 fly, and 6 ticks. Overall, Qatar benefits currently from a good surveillance of some VBDs (malaria) and has some capacities in vector control, but no national plan exists, and vector surveillance is in its infancy. In Qatar, clear needs exist in capacity in epidemiology and vector entomology, as well as on the organisational level, and a number of measures are suggested to mitigate and improve VBD risk assessment and management. There is an urgent need to define sustainable solutions for VBD control, management and prevention, and a number of recommendations are suggested.

scholarly journals Epidemiology of imported infectious diseases, China, 2014–18

2020 ◽  
Vol 27 (8) ◽  
Author(s):  
Yang Wu ◽  
Meng-Yang Liu ◽  
Jin-Long Wang ◽  
Hai-Yang Zhang ◽  
Yu Sun ◽  
...  
Keyword(s):  
Respiratory Infections ◽  
Gastrointestinal Diseases ◽  
International Travel ◽  
Asian Countries ◽  
African Countries ◽  
Sexually Transmitted ◽  
Vector Borne Diseases ◽  
Place Of Origin ◽  
Vector Borne ◽  
Imported Infections

Abstract Background The frequent movement of population between countries brings an increasing number of travel-related infections. This study aims to define the spectrum and dynamics of imported infections observed from international travel in the Chinese mainland. Methods Sick travellers were screened by inbound sentinel surveillance and post-travel clinic visits from 2014 to 18. The infections were classified as respiratory, gastrointestinal, vector-borne, blood/sexually transmitted and mucocutaneous. The analysed variables included the place of origin of the travellers (Chinese or foreign) and the time when travel-related infection was present (at the time of return, during travel and post-travel visits to the clinic). Results In total, 58 677 cases were identified amongst 1 409 265 253 travellers, with an incidence of 41.64/million, comprising during-travel incidence of 27.44/million and a post-travel incidence of 14.20/million. Respiratory infections constituted the highest proportion of illnesses during travel (81.19%, 31 393 of 38 667), which mainly came from Asian countries and tourists; with influenza virus and rhinovirus infections being mainly diagnosed. Vector-borne diseases constituted the highest proportion of post-travel illnesses (98.14%, 19 638 of 20 010), which were mainly diagnosed from African countries and labourers; with malaria and dengue fever being mainly diagnosed. The differential infection spectrum varied in terms of the traveller’s demography, travel destination and travel purpose. As such, a higher proportion of foreign travellers had blood/sexually transmitted diseases (89.85%, 2832 of 3152), while Chinese citizens had a higher prevalence of vector-borne diseases (85.98%, 19 247 of 22 387) and gastrointestinal diseases (79.36%, 1115 of 1405). The highest incidence rate was observed amongst travellers arriving from Africa, while the lowest was observed amongst travellers arriving from Europe. Conclusions The findings might help in preparing recommendations for travellers and also aid in primary care or other clinics that prepare travellers before trips abroad. The findings will also help to identify locations and the associated types of infections that might require attention.

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.

scholarly journals Decoys and dilution: the impact of incompetent hosts on prevalence of Chagas disease

2019 ◽  
Author(s):  
Mondal Hasan Zahid ◽  
Christopher M. Kribs
Keyword(s):  
Chagas Disease ◽  
Disease Transmission ◽  
Birth Rate ◽  
Parasite Prevalence ◽  
Human Infection ◽  
Vector Borne Diseases ◽  
Intermediate Distance ◽  
Vector Borne ◽  
Reduce Risk ◽  
The Impact

AbstractBiodiversity is commonly believed to reduce risk of vector-borne zoonoses. However, researchers already showed that the effect of biodiversity on disease transmission is not that straightforward. This study focuses on the effect of biodiversity, specifically on the effect of the decoy process (additional hosts distracting vectors from their focal host), on reducing infections of vector-borne diseases in humans. Here, we consider the specific case of Chagas disease and use mathematical population models to observe the impact on human infection of the proximity of chickens, which are incompetent hosts for the parasite but serve as a preferred food source for vectors. We consider three cases as the distance between the two host populations varies: short (when farmers bring chickens inside the home to protect them from predators), intermediate (close enough for vectors with one host to detect the presence of the other host type), and far (separate enclosed buildings such as a home and hen-house). Our analysis shows that the presence of chickens reduces parasite prevalence in humans only at an intermediate distance under the condition that the vector birth rate from feeding on chickens is sufficiently low.

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