scholarly journals Dynamics and Biocontrol: The Indirect Effects of a Predator Population on a Host-Vector Disease Model

2014 ◽  
Vol 2014 ◽  
pp. 1-14 ◽  
Author(s):  
Fengyan Zhou ◽  
Hongxing Yao
Keyword(s):  
Disease Model ◽  
Transmitted Disease ◽  
Host Population ◽  
Uniform Persistence ◽  
Predator Population ◽  
Insect Vector ◽  
Vector Borne Diseases ◽  
Vector Population ◽  
Reproduction Numbers ◽  
Vector Borne

A model of the interactions among a host population, an insect-vector population, which transmits virus from hosts to hosts, and a vector predator population is proposed based on virus-host, host-vector, and prey (vector)-enemy theories. The model is investigated to explore the indirect effect of natural enemies on host-virus dynamics by reducing the vector densities, which shows the basic reproduction numbersR01(without predators) andR02(with predators) that provide threshold conditions on determining the uniform persistence and extinction of the disease in a host population. When the model is absent from predator, the disease is persistent ifR01>1; in such a case, by introducing predators of a vector, then the insect-transmitted disease will be controlled ifR02<1. From the point of biological control, these results show that an additional predator population of the vector may suppress the spread of vector-borne diseases. In addition, there exist limit cycles with persistence of the disease or without disease in presence of predators. Finally, numerical simulations are conducted to support analytical results.

scholarly journals Bifurcation Analysis in Models for Vector-Borne Diseases with Logistic Growth

2014 ◽  
Vol 2014 ◽  
pp. 1-9
Author(s):  
Guihua Li ◽  
Zhen Jin
Keyword(s):  
Death Rate ◽  
Host Population ◽  
Backward Bifurcation ◽  
Logistic Growth ◽  
Natural Death ◽  
Vector Borne Diseases ◽  
Vector Population ◽  
Existence And Stability ◽  
Vector Borne ◽  
Parameter Varying

We establish and study vector-borne models with logistic and exponential growth of vector and host populations, respectively. We discuss and analyses the existence and stability of equilibria. The model has backward bifurcation and may have no, one, or two positive equilibria when the basic reproduction numberR0is less than one and one, two, or three endemic equilibria whenR0is greater than one under different conditions. Furthermore, we prove that the disease-free equilibrium is stable ifR0is less than 1, it is unstable otherwise. At last, by numerical simulation, we find rich dynamical behaviors in the model. By taking the natural death rate of host population as a bifurcation parameter, we find that the system may undergo a backward bifurcation, saddle-node bifurcation, Hopf bifurcation, Bogdanov-Takens bifurcation, and cusp bifurcation with the saturation parameter varying. The natural death rate of host population is a crucial parameter. If the natural death rate is higher, then the host population and the disease will die out. If it is smaller, then the host and vector population will coexist. If it is middle, the period solution will occur. Thus, with the parameter varying, the disease will spread, occur periodically, and finally become extinct.

scholarly journals Bayesian data assimilation provides rapid decision support for vector-borne diseases

2015 ◽  
Vol 12 (108) ◽  
pp. 20150367 ◽  
Author(s):  
Chris P. Jewell ◽  
Richard G. Brown
Keyword(s):  
Decision Support ◽  
Data Assimilation ◽  
Population Data ◽  
Disease Status ◽  
Host Population ◽  
Significant Advance ◽  
Model Parameters ◽  
Vector Borne Diseases ◽  
Vector Borne ◽  
Bayesian Data Assimilation

Predicting the spread of vector-borne diseases in response to incursions requires knowledge of both host and vector demographics in advance of an outbreak. Although host population data are typically available, for novel disease introductions there is a high chance of the pathogen using a vector for which data are unavailable. This presents a barrier to estimating the parameters of dynamical models representing host–vector–pathogen interaction, and hence limits their ability to provide quantitative risk forecasts. The Theileria orientalis (Ikeda) outbreak in New Zealand cattle demonstrates this problem: even though the vector has received extensive laboratory study, a high degree of uncertainty persists over its national demographic distribution. Addressing this, we develop a Bayesian data assimilation approach whereby indirect observations of vector activity inform a seasonal spatio-temporal risk surface within a stochastic epidemic model. We provide quantitative predictions for the future spread of the epidemic, quantifying uncertainty in the model parameters, case infection times and the disease status of undetected infections. Importantly, we demonstrate how our model learns sequentially as the epidemic unfolds and provide evidence for changing epidemic dynamics through time. Our approach therefore provides a significant advance in rapid decision support for novel vector-borne disease outbreaks.

The dynamics of vector-transmitted diseases in human communities

1988 ◽  
Vol 321 (1207) ◽  
pp. 513-539 ◽  
Keyword(s):  
Disease Transmission ◽  
Disease Model ◽  
Transmitted Disease ◽  
Field Studies ◽  
Human Host ◽  
Large Numbers ◽  
Reservoir Species ◽  
Single Feature ◽  
Trypanosomatid Parasites ◽  
Vector Borne

The development of vector-transmitted disease models and their application to field studies is reviewed. The key concepts of the basic rate of reproduction and disease transmission threshold are explained, and their application to disease control briefly illustrated. The complications involved in producing appropriate models are discussed for the case of the trypanosomatid parasites Leishmania and Trypanosoma that frequently have more than one vertebrate host and are often fatal in the human host. A two-species, vector-borne disease model allows a quantification of the role of animal reservoirs in maintaining human diseases. Human prevalence may be determined more by the parasitological characteristics of wild reservoir species, about which little is generally known, than by any other single feature of the complex interaction between parasites, vectors and hosts. Domestic animals are often ideal reservoirs, maintaining large numbers of vectors and considerably enlarging the parasite pool. When vector-transmitted diseases are fatal to the human host, human and vector dynamics interact in ways which may cause epidemic cycles, low-level endemic equilibria or disease extinction. For both leishmaniasis and trypanosomiasis it is suggested that a very small number of chronic human cases can maintain the disease in the human population over long periods of time between epidemic outbreaks. They may also be important in the maintenance of geographically distinct foci, characteristic of human trypanosomiasis in Africa. Finally there is a plea to establish a tradition of field observation leading to, and being directed by, mathematical models which in turn are modified as the observations accumulate. All too often, one-way traffic between the two results in slow, or misguided, progress.

Community Perception Regarding Mosquito-Borne Diseases in Some Selected Areas of Ganjam District of Odisha State, India

2021 ◽  
pp. 0272684X2110049
Author(s):  
Sisir K Nayak ◽  
Surya N Swain ◽  
T Sarita Achari ◽  
Tapan K Barik
Keyword(s):  
Disease Incidence ◽  
Basic Knowledge ◽  
Health Concern ◽  
Mosquito Vector ◽  
College Level ◽  
Community Perception ◽  
Vector Borne Diseases ◽  
Vector Population ◽  
Vector Borne ◽  
Ganjam District

Mosquito-borne diseases are a major public health concern. Because of absence of effective therapy and vaccination to treat and prevent such vector-borne diseases, these initial cases have triggered strong concerns within medical communities, turning a bad dream into reality. To date, reducing the mosquito vector population remains the main strategy to control the transmission of mosquito borne diseases. In this connection, community-based perception recognized as an essential tool for long-term vector control management. In this study, a community perception survey was carried out in six selected study areas of Ganjam district of Odisha. A total of 3257 inhabitants from randomly chosen 600 no. of houses from 06 selected study areas were interviewed using a pre-tested structured questionnaire about various mosquito vector-borne diseases. As an outcome, we found that only 36% of people have basic knowledge and idea about vector-borne diseases, out of which only 14% know Anopheles as a causative agent whereas Aedes and Culex were very least concern. Regarding the source of knowledge, electronic media was the principal source of information, while the involvements of health personnel were least mentioned. Results of the current study indicates the necessity to plan health education program to bring important perceptions regarding vector-borne diseases at school and college level because the infrequent source of knowledge is the main cause of an increase in the disease incidence.

scholarly journals ENTOMOLOGICAL PARAMETERS AND CHARACTERIZATION OF INSECTICIDE RESISTANCE IN DENGUE VECTOR AEDES AEGYPTI LARVAE FROM BENGKULU CITY, INDONESIA

2021 ◽  
Vol 21 (1) ◽  
pp. 96-102
Author(s):  
Dessy Triana ◽  
Fitaloca N Siregar ◽  
Eka Purnama Wulan Tri Utami ◽  
Tatik Suteky ◽  
Swandito Wicaksono
Keyword(s):  
Aedes Aegypti ◽  
Cross Sectional ◽  
Vector Borne Diseases ◽  
Control Programs ◽  
Vector Population ◽  
Who 1999 Criteria ◽  
Vector Borne ◽  
Dengue Control ◽  
Breeding Place

In Bengkulu, as in other areas of Indonesia, dengue is one of the most important vector-borne diseases. The primary strategy to control dengue is by reducing the vector population using insecticides. However, applications of insecticides becomes a contributing factor in the development of vector resistance. As there is no effective dengue drug or safe vaccine available, vector control remains the most effective intervention to reduce incidence and prevent transmission and outbreak. This study aimed to determine the entomological parameters and resistance status to temephos of Aedes aegypti larvae from Lingkar Barat village and Jalan Gedang village (dengue endemic areas). This study used cross-sectional and experimental with post-control only design. The sampling refers to the guidelines for dengue entomology surveys according to WHO 1999 criteria. Aedes aegypti eggs were collected by ovitraps and reared to larvae stage. Susceptibility test of larvae to the temephos was estimated using standard WHO. Mortality of larvae Ae. aegypti after 24 hours with multiple concentration of temephos indicative of highly resistant.  Entomological parameters for house index (HI), container index (CI) and container pupa index (CPI) in Jalan Gedang village and Lingkar Barat village were estimated: 7%, 12% for HI and 1.97%, 3.43% for CI, and 5%, 2% for CPI, respectively. The proportion of controllable sites is higher than disposable sites, it has a high risk as breeding places for mosquitoes indicates a high potential risk as breeding place and transmission of dengue. Awareness sanitation in the home and surrounding environment must be possessed by each individual community in order to prevent and overcome the incidence of dengue. These data should be of value in formulating dengue control programs.

scholarly journals Clustered Breeding Sites: Shelters for Vector-Borne Diseases

2018 ◽  
Vol 2018 ◽  
pp. 1-5 ◽  
Author(s):  
J. C. A. Dias ◽  
L. H. A. Monteiro
Keyword(s):  
Host Population ◽  
Spatial Distributions ◽  
Breeding Sites ◽  
Vector Borne Diseases ◽  
Vector Abundance ◽  
Probabilistic Cellular Automaton ◽  
Time Variations ◽  
Vector Borne ◽  
Clustered Distributions ◽  
Homogeneous Distributions

Here, the propagation of vector-borne diseases is modeled by using a probabilistic cellular automaton. Numerical simulations considering distinct spatial distributions and time variations of the vector abundance are performed, in order to investigate their impacts on the number of infected individuals of the host population. The main conclusion is as follows: in the clustered distributions, the prevalence is lower, but the eradication is more difficult to be achieved, as compared to homogeneous distributions. This result can be relevant in the implementation of preventive surveillance measures.

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