scholarly journals A Framework for Weather-Driven Dengue Virus Transmission Dynamics in Different Brazilian Regions

2021 ◽  
Vol 18 (18) ◽  
pp. 9493
Author(s):  
Leon Diniz Alves ◽  
Raquel Martins Lana ◽  
Flávio Codeço Coelho
Keyword(s):  
Vertical Transmission ◽  
Virus Transmission ◽  
Transmission Dynamics ◽  
Transmission Model ◽  
Egg Hatching ◽  
Climate Fluctuations ◽  
Dengue Transmission ◽  
Proposed Model ◽  
Environment Variables

This study investigated a model to assess the role of climate fluctuations on dengue (DENV) dynamics from 2010 to 2019 in four Brazilian municipalities. The proposed transmission model was based on a preexisting SEI-SIR model, but also incorporates the vector vertical transmission and the vector’s egg compartment, thus allowing rainfall to be introduced to modulate egg-hatching. Temperature and rainfall satellite data throughout the decade were used as climatic model inputs. A sensitivity analysis was performed to understand the role of each parameter. The model-simulated scenario was compared to the observed dengue incidence and the findings indicate that the model was able to capture the observed seasonal dengue incidence pattern with good accuracy until 2016, although higher deviations were observed from 2016 to 2019. The results further demonstrate that vertical transmission fluctuations can affect attack transmission rates and patterns, suggesting the need to investigate the contribution of vertical transmission to dengue transmission dynamics in future assessments. The improved understanding of the relationship between different environment variables and dengue transmission achieved by the proposed model can contribute to public health policies regarding mosquito-borne diseases.

scholarly journals Projections of increased and decreased dengue incidence under climate change

2016 ◽  
Vol 144 (14) ◽  
pp. 3091-3100 ◽  
Author(s):  
C. R. WILLIAMS ◽  
G. MINCHAM ◽  
H. FADDY ◽  
E. VIENNET ◽  
S. A. RITCHIE ◽  
...  
Keyword(s):  
Climate Change ◽  
Climate Warming ◽  
Carbon Emission ◽  
Climate Models ◽  
Virus Transmission ◽  
Transmission Model ◽  
Simple Relationship ◽  
Breeding Sites ◽  
Dengue Transmission ◽  
Dengue Epidemic

SUMMARYDengue is the world's most prevalent mosquito-borne disease, with more than 200 million people each year becoming infected. We used a mechanistic virus transmission model to determine whether climate warming would change dengue transmission in Australia. Using two climate models each with two carbon emission scenarios, we calculated future dengue epidemic potential for the period 2046–2064. Using the ECHAM5 model, decreased dengue transmission was predicted under the A2 carbon emission scenario, whereas some increases are likely under the B1 scenario. Dengue epidemic potential may decrease under climate warming due to mosquito breeding sites becoming drier and mosquito survivorship declining. These results contradict most previous studies that use correlative models to show increased dengue transmission under climate warming. Dengue epidemiology is determined by a complex interplay between climatic, human host, and pathogen factors. It is therefore naive to assume a simple relationship between climate and incidence, and incorrect to state that climate warming will uniformly increase dengue transmission, although in general the health impacts of climate change will be negative.

scholarly journals A Two-Patch Mathematical Model for Temperature-Dependent Dengue Transmission Dynamics

Processes ◽  
2020 ◽  
Vol 8 (7) ◽  
pp. 781
Author(s):  
Jung Kim ◽  
Yongin Choi ◽  
James Kim ◽  
Sunmi Lee ◽  
Chang Lee
Keyword(s):  
Climate Change ◽  
Vector Control ◽  
Control Strategies ◽  
Virus Transmission ◽  
Transmission Dynamics ◽  
Transmission Control ◽  
Temperature Dependent ◽  
Tropical Regions ◽  
Patch Model ◽  
Dengue Transmission

Dengue fever has been a threat to public health not only in tropical regions but non-tropical regions due to recent climate change. Motivated by a recent dengue outbreak in Japan, we develop a two-patch model for dengue transmission associated with temperature-dependent parameters. The two patches represent a park area where mosquitoes prevail and a residential area where people live. Based on climate change scenarios, we investigate the dengue transmission dynamics between the patches. We employ an optimal control method to implement proper control measures in the two-patch model. We find that blockage between two patches for a short-term period is effective in a certain degree for the disease control, but to obtain a significant control effect of the disease, a long-term blockage should be implemented. Moreover, the control strategies such as vector control and transmission control are very effective, if they are implemented right before the summer outbreak. We also investigate the cost-effectiveness of control strategies such as vaccination, vector control and virus transmission control. We find that vector control and virus transmission control are more cost-effective than vaccination in case of Korea.

scholarly journals The impact of the undetected COVID-19 cases on its transmission dynamics

2020 ◽  
Author(s):  
Sujata Saha ◽  
Sumanta Saha
Keyword(s):  
Basic Reproduction Number ◽  
Reproduction Number ◽  
Disease Risk ◽  
Transmission Dynamics ◽  
Transmission Model ◽  
Risk Of Infection ◽  
Infection Transmission ◽  
Reported Data ◽  
The Impact

AbstractObjectiveThe COVID-19 pandemic is currently ongoing. Presently, due to the unavailability of a definitive vaccine to decrease its acquiring, it’s essential to understand its transmissibility in the community by undetected cases to control its transmission. This study aims to study this context using mathematical modelling.MethodsA COVID-19 transmission model was framed that estimated the basic reproduction number (R0, a measurement of disease risk) using the next-generation method. It explored the contribution of exposed and infected (detected and undetected) individuals, and environmental pathogen to the overall risk of infection spreading, utilizing the publicly reported data of this infection in Maharashtra between March 22, 2020, and May 4, 2020. A sensitivity analysis was performed to study the effect of a rising number of undetected cases to R0.ResultsThe estimated basic reproduction number is R0 = 4.63, which increases rapidly with the rise in the undetected COVID-19 cases. Although the exposed individuals made the largest contribution to infection transmission (R1 = 2.42), the contaminated environment also played a significant role.ConclusionsIt is crucial to identify the individuals exposed and infected to COVID-19 disease and isolate them to control its transmission. The awareness of the role of fomites in infection transmission is also important in this regard.

scholarly journals Mathematical model and analysis of hepatitis B virus transmission dynamics

F1000Research ◽  
2018 ◽  
Vol 7 ◽  
pp. 1312 ◽  
Author(s):  
Blessing O. Emerenini ◽  
Simeon C. Inyama
Keyword(s):  
Hepatitis B Virus ◽  
Hepatitis B ◽  
Virus Transmission ◽  
Transmission Dynamics ◽  
Seir Model ◽  
Hbv Vaccination ◽  
B Virus ◽  
Different Populations ◽  
Liver Infection

Hepatitis B is a liver infection induced by the hepatitis B virus (HBV). In this paper, the dynamics involved in the transmission of HBV is mathematically formulated with considerations of different populations of individuals. The role of HBV vaccination of new born babies and the treatment of infected individuals in controlling the transmission are factored into the model. The model in this study is based on the standard SEIR model.

Social Networking Sites Continuance: An Application of Extended Theory of Planned Behaviour

2015 ◽  
Vol 8 (1) ◽  
Author(s):  
Himanshu Rajput
Keyword(s):  
Social Networking ◽  
Social Networking Sites ◽  
Theory Of Planned Behaviour ◽  
Standard Theory ◽  
Planned Behaviour ◽  
Privacy Concerns ◽  
Proposed Model ◽  
Continued Use ◽  
Moderating Role

Social networking sites (SNSs) have become popular in India with the proliferation of Internet. SNSs have gained the interests of academicians and researchers. The current study is an endeavor to understand the continuance of social networking sites in India. The study applies an extended version of theory of planned behavior. Additional factors privacy concerns and habits were incorporated into the standard theory of planned behaviour. A survey was conducted in a Central University in India. Overall, data was collected from 150 respondents. PLS-SEM was used to test the proposed model. All the hypotheses except the moderating role of habits between intentions and continued use of social networking sites, were supported by the results. Habits were found to affect continued use of social networking sites indirectly through continued intentions.

scholarly journals Model-based evaluation of school- and non-school-related measures to control the COVID-19 pandemic

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Ganna Rozhnova ◽  
Christiaan H. van Dorp ◽  
Patricia Bruijning-Verhagen ◽  
Martin C. J. Bootsma ◽  
Janneke H. H. M. van de Wijgert ◽  
...  
Keyword(s):  
Reproduction Number ◽  
Additional Benefit ◽  
Transmission Model ◽  
Time Points ◽  
School Based ◽  
Admission Data ◽  
Age Structured ◽  
The Impact ◽  
Pandemic Wave

AbstractThe role of school-based contacts in the epidemiology of SARS-CoV-2 is incompletely understood. We use an age-structured transmission model fitted to age-specific seroprevalence and hospital admission data to assess the effects of school-based measures at different time points during the COVID-19 pandemic in the Netherlands. Our analyses suggest that the impact of measures reducing school-based contacts depends on the remaining opportunities to reduce non-school-based contacts. If opportunities to reduce the effective reproduction number (Re) with non-school-based measures are exhausted or undesired and Re is still close to 1, the additional benefit of school-based measures may be considerable, particularly among older school children. As two examples, we demonstrate that keeping schools closed after the summer holidays in 2020, in the absence of other measures, would not have prevented the second pandemic wave in autumn 2020 but closing schools in November 2020 could have reduced Re below 1, with unchanged non-school-based contacts.

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