scholarly journals SIR Model for Dengue Disease with Effect of Dengue Vaccination

2018 ◽  
Vol 2018 ◽  
pp. 1-14 ◽  
Author(s):  
Pratchaya Chanprasopchai ◽  
I. Ming Tang ◽  
Puntani Pongsumpun
Keyword(s):  
Mathematical Model ◽  
Mortality Rate ◽  
Dengue Virus ◽  
Numerical Solutions ◽  
Specific Treatment ◽  
Sir Model ◽  
Dengue Vaccine ◽  
Dengue Disease ◽  
Modelling Methods

The dengue disease is caused by dengue virus, and there is no specific treatment. The medical care by experienced physicians and nurses will save life and will lower the mortality rate. A dengue vaccine to control the disease is available in Thailand since late 2016. A mathematical model would be an important way to analyze the effects of the vaccination on the transmission of the disease. We have formulated an SIR (susceptible-infected-recovered) model of the transmission of the disease which includes the effect of vaccination and used standard dynamical modelling methods to analyze the effects. The equilibrium states and their stabilities are investigated. The trajectories of the numerical solutions plotted into the 2D planes and 3D spaces are presented. The main contribution is determining the role of dengue vaccination in the model. From the analysis, we find that there is a significant reduction in the total hospitalization time needed to treat the illness.

scholarly journals The Potential Influence of Vitamin A, C, and D and Zinc Supplements on the Severity of COVID-19 Symptoms and Clinical Outcomes: An Updated Review of Literature

2020 ◽  
Vol 8 (3) ◽  
pp. 703-714
Author(s):  
Abeer Salman Alzaben
Keyword(s):  
Mortality Rate ◽  
Vitamin A ◽  
Clinical Outcomes ◽  
Potential Role ◽  
Randomized Clinical Trials ◽  
Respiratory Infections ◽  
Specific Treatment ◽  
Zinc Supplements ◽  
Different Doses

Coronavirus disease-19 (COVID-19) caused by the severe acute respiratory syndrome coronavirus 2 is an ongoing viral epidemic that originated in China in December 2019. To date, no specific treatment is available for COVID-19. However, several studies have reported the benefits of vitamins A, C, and D and zinc in critically ill patients and in those with various infections, including respiratory infections and sepsis. The objective of this review is to discuss the potential role of vitamin A, C, and D and zinc supplementation in enhancing immune response, and reducing the severity of symptoms, and mortality rate in patients with COVID-19. Several clinical studies have shown that different doses of vitamins A, C, and D and/or zinc supplements reduce the ventilator, length of intensive care unit stay, and mortality rate. Future randomized clinical trials are warranted to conclusively establish protocols for the optimal doses of vitamin A, C, and D, as well as zinc supplements for improved clinical outcomes in patients with COVID-19.

scholarly journals Adaptive Immunity to Dengue Virus: Slippery Slope or Solid Ground for Rational Vaccine Design?

Pathogens ◽  
2020 ◽  
Vol 9 (6) ◽  
pp. 470 ◽  
Author(s):  
Lucas Wilken ◽  
Guus F. Rimmelzwaan
Keyword(s):  
Dengue Virus ◽  
Vaccine Development ◽  
Secondary Infection ◽  
Severe Disease ◽  
Structural Protein ◽  
Dengue Vaccine ◽  
Dengue Disease ◽  
Generation Vaccine ◽  
Virus Serotype ◽  
Rational Vaccine Design

The four serotypes of dengue virus are the most widespread causes of arboviral disease, currently placing half of the human population at risk of infection. Pre-existing immunity to one dengue virus serotype can predispose to severe disease following secondary infection with a different serotype. The phenomenon of immune enhancement has complicated vaccine development and likely explains the poor long-term safety profile of a recently licenced dengue vaccine. Therefore, alternative vaccine strategies should be considered. This review summarises studies dissecting the adaptive immune responses to dengue virus infection and (experimental) vaccination. In particular, we discuss the roles of (i) neutralising antibodies, (ii) antibodies to non-structural protein 1, and (iii) T cells in protection and pathogenesis. We also address how these findings could translate into next-generation vaccine approaches that mitigate the risk of enhanced dengue disease. Finally, we argue that the development of a safe and efficacious dengue vaccine is an attainable goal.

scholarly journals Changes in complement alternative pathway components, factor B and factor H during dengue virus infection in the AG129 mouse

2021 ◽  
Author(s):  
Sheila Cabezas-Falcon ◽  
Aidan J. Norbury ◽  
Jarrod Hulme-Jones ◽  
Sonja Klebe ◽  
Penelope Adamson ◽  
...  
Keyword(s):  
Dengue Virus ◽  
Alternative Pathway ◽  
Severe Disease ◽  
Denv Infection ◽  
Factor H ◽  
Severe Dengue ◽  
Complement Alternative Pathway ◽  
Factor B ◽  
Dengue Disease

The complement alternative pathway (AP) is tightly regulated and changes in two important AP components, factor B (FB) and factor H (FH) are linked to severe dengue in humans. Here, a mouse model of dengue was investigated to define the changes in FB and FH and assess the utility of this model to study the role of the AP in severe dengue. Throughout the period of viremia in the AG129 IFN signalling-deficient mouse, an increase in FB and a decrease in FH was observed following dengue virus (DENV) infection, with the former only seen in a model of more severe disease associated with antibody-dependent enhancement (ADE). Terminal disease was associated with a decrease in FB and FH, with greater changes during ADE, and accompanied by increased C3 degradation consistent with complement activation. In silico analysis of NFκΒ, signal transducer and activator of transcription (STAT) and IFN-driven FB and FH promoter elements to reflect the likely impact of the lack of IFN-responses in AG129 mice, demonstrated that these elements differed markedly between human and mouse, notably with mouse FH lacking NFκΒ and key IFN-stimulated response elements (ISRE), and FB with many more NFκΒ and STAT-responsive elements than human FB. Thus, the AG129 mouse offers utility in demonstrating changes in FB and FH that, similar to humans, are associated with severe disease, but lack predicted important human-specific and IFN-dependent responses of FB and FH to DENV-infection that are likely to regulate the subtleties of the overall AP response during dengue disease in humans.

scholarly journals Serum LPS Associated with Hantavirus and Dengue Disease Severity in Barbados

Viruses ◽  
2019 ◽  
Vol 11 (9) ◽  
pp. 838
Author(s):  
Kirk Douglas ◽  
Thelma Samuels ◽  
Marquita Gittens-St. Hilaire
Keyword(s):  
Dengue Virus ◽  
Disease Severity ◽  
Elevated Serum ◽  
Severe Dengue ◽  
Hantavirus Infection ◽  
Dengue Virus Infection ◽  
Dengue Disease ◽  
Co Detection ◽  
First Time

Hantavirus and dengue virus (DENV) infections are caused by RNA viruses which infect immune systems’ cells including monocytes, macrophages and dendritic cells and occur year-round in Barbados. A retrospective serological study (2008–2015) was conducted on hantavirus and dengue patient sera confirmed by IgM and IgG ELISA, NS1 and RT-PCR using Limulus amoebocyte lysate (LAL) kinetic turbidimetric method to determine serum endotoxin levels. Hantavirus patients were categorized into two groups, namely (a) hospitalized and (b) non-hospitalized. Dengue patients were categorized into 3 groups using 2009 WHO dengue guidelines (a) severe dengue (SD), (b) hospitalized non-severe dengue (non-SD) and (c) non-hospitalized non-SD. Statistical analyses were conducted to determine the association of endotoxin levels with hantavirus disease severity based on hospitalization and dengue disease severity. Serum endotoxin levels are associated with hantavirus disease severity and hospitalization and dengue disease severity (p < 0.01). Similar studies have found an association of serum endotoxin levels with dengue disease severity but never with hantavirus infection. Co-detection of hantavirus- and DENV-specific IgM in some patients were observed with elevated serum endotoxin levels. In addition, previous studies observed hantavirus replication in the gut of patients, gastrointestinal tract as a possible entry route of infection and evidence of microbial translocation and its impact on hantavirus disease severity. A significant correlation of serum endotoxin and hantavirus disease severity and hospitalization in hantavirus infected patients is reported for the first time ever. In addition, serum endotoxin levels correlated with dengue disease severity. This study adds further support to the role of endotoxin in both hantavirus and dengue virus infection and disease severity and its role as a possible therapeutic target for viral haemorrhagic fevers (VHFs).

scholarly journals Local and Global Stability Analysis of Dengue Disease with Vaccination and Optimal Control

Symmetry ◽  
2021 ◽  
Vol 13 (10) ◽  
pp. 1917
Author(s):  
Anusit Chamnan ◽  
Puntani Pongsumpun ◽  
I-Ming Tang ◽  
Napasool Wongvanich
Keyword(s):  
Optimal Control ◽  
Control Systems ◽  
Numerical Solutions ◽  
Dengue Infection ◽  
Transmission Model ◽  
Dengue Vaccine ◽  
Dengue Disease ◽  
Global Stability Analysis ◽  
Aedes Mosquitoes ◽  
Dengue Transmission

Dengue fever is a disease that has spread all over the world, including Thailand. Dengue is caused by a virus and there are four distinct serotypes of the virus that cause dengue DENV-1, DENV-2, DENV-3, and DENV-4. The dengue viruses are transmitted by two species of the Aedes mosquitoes, the Aedes aegypti, and the Aedes albopictus. Currently, the dengue vaccine used in Thailand is chimeric yellow tetravalent dengue (CYD-TDV). This research presents optimal control which studies the vaccination only in individuals with a documented past dengue infection (seropositive), regardless of the serotypes of infection causing the initial infection by the disease. The analysis of dengue transmission model is used to establish the local asymptotically stabilities. The property of symmetry in the Lyapunov function an import role in achieving this global asymptotically stabilities. The optimal control systems are shown in numerical solutions and conclusions. The result shows that the control resulted in a significant reduction in the number of infected humans and infected vectors.

scholarly journals Humanized Mice in Dengue Research: A Comparison with Other Mouse Models

Vaccines ◽  
2020 ◽  
Vol 8 (1) ◽  
pp. 39 ◽  
Author(s):  
Carolina Coronel-Ruiz ◽  
Hernando Gutiérrez-Barbosa ◽  
Sandra Medina-Moreno ◽  
Myriam L. Velandia-Romero ◽  
Joel V. Chua ◽  
...  
Keyword(s):  
Mouse Models ◽  
Clinical Signs ◽  
Specific Treatment ◽  
Inflammatory Factors ◽  
Humanized Mouse ◽  
Full Spectrum ◽  
Dengue Disease ◽  
Cell Responses ◽  
Life Threatening

Dengue virus (DENV) is an arbovirus of the Flaviviridae family and is an enveloped virion containing a positive sense single-stranded RNA genome. DENV causes dengue fever (DF) which is characterized by an undifferentiated syndrome accompanied by fever, fatigue, dizziness, muscle aches, and in severe cases, patients can deteriorate and develop life-threatening vascular leakage, bleeding, and multi-organ failure. DF is the most prevalent mosquito-borne disease affecting more than 390 million people per year with a mortality rate close to 1% in the general population but especially high among children. There is no specific treatment and there is only one licensed vaccine with restricted application. Clinical and experimental evidence advocate the role of the humoral and T-cell responses in protection against DF, as well as a role in the disease pathogenesis. A lot of pro-inflammatory factors induced during the infectious process are involved in increased severity in dengue disease. The advances in DF research have been hampered by the lack of an animal model that recreates all the characteristics of this disease. Experiments in nonhuman primates (NHP) had failed to reproduce all clinical signs of DF disease and during the past decade, humanized mouse models have demonstrated several benefits in the study of viral diseases affecting humans. In DENV studies, some of these models recapitulate specific signs of disease that are useful to test drugs or vaccine candidates. However, there is still a need for a more complete model mimicking the full spectrum of DENV. This review focuses on describing the advances in this area of research.

scholarly journals Dengue Fever: Causes, Complications, and Vaccine Strategies

2016 ◽  
Vol 2016 ◽  
pp. 1-14 ◽  
Author(s):  
Niyati Khetarpal ◽  
Ira Khanna
Keyword(s):  
Dengue Virus ◽  
Vaccine Development ◽  
Vaccine Candidate ◽  
Hemorrhagic Fever ◽  
Dengue Vaccine ◽  
Dengue Disease ◽  
The Public ◽  
Limited Application ◽  
Demographic Distribution ◽  
The Impact

Dengue is a highly endemic infectious disease of the tropical countries and is rapidly becoming a global burden. It is caused by any of the 4 serotypes of dengue virus and is transmitted within humans through femaleAedesmosquitoes. Dengue disease varies from mild fever to severe conditions of dengue hemorrhagic fever and shock syndrome. Globalization, increased air travel, and unplanned urbanization have led to increase in the rate of infection and helped dengue to expand its geographic and demographic distribution. Dengue vaccine development has been a challenging task due to the existence of four antigenically distinct dengue virus serotypes, each capable of eliciting cross-reactive and disease-enhancing antibody response against the remaining three serotypes. Recently, Sanofi Pasteur’s chimeric live-attenuated dengue vaccine candidate has been approved in Mexico, Brazil, and Philippines for usage in adults between 9 and 45 years of age. The impact of its limited application to the public health system needs to be evaluated. Simultaneously, the restricted application of this vaccine candidate warrants continued efforts in developing a dengue vaccine candidate which is additionally efficacious for infants and naïve individuals. In this context, alternative strategies of developing a designed vaccine candidate which does not allow production of enhancing antibodies should be explored, as it may expand the umbrella of efficacy to include infants and naïve individuals.

Treatment of ebola and other infectious diseases: melatonin “goes viral”

2020 ◽  
Vol 3 (1) ◽  
pp. 43-57 ◽  
Author(s):  
Russel J Reiter ◽  
Qiang Ma ◽  
Ramaswamy Sharma
Keyword(s):  
Mortality Rate ◽  
Infectious Diseases ◽  
Hemorrhagic Shock ◽  
Safety Profile ◽  
Ebola Virus ◽  
Viral Infections ◽  
Virus Disease ◽  
Attractive Potential ◽  
Potential Treatment

This review summarizes published reports on the utility of melatonin as a treatment for virus-mediated diseases. Of special note are the data related to the role of melatonin in influencing Ebola virus disease. This infection and deadly condition has no effective treatment and the published works documenting the ability of melatonin to attenuate the severity of viral infections generally and Ebola infection specifically are considered. The capacity of melatonin to prevent one of the major complications of an Ebola infection, i.e., the hemorrhagic shock syndrome, which often contributes to the high mortality rate, is noteworthy. Considering the high safety profile of melatonin, the fact that it is easily produced, inexpensive and can be self-administered makes it an attractive potential treatment for Ebola virus pathology.  

The Impact of Light Polarisation on Light Field of Scenes with Multiple Reflections

2020 ◽  
pp. 108-115 ◽  
Author(s):  
Vladimir P. Budak ◽  
Anton V. Grimaylo
Keyword(s):  
Mathematical Model ◽  
Light Field ◽  
Global Illumination ◽  
Multiple Reflections ◽  
Software Environment ◽  
The Monte Carlo Method ◽  
Mueller Matrices ◽  
Volume Integration ◽  
The Impact

The article describes the role of polarisation in calculation of multiple reflections. A mathematical model of multiple reflections based on the Stokes vector for beam description and Mueller matrices for description of surface properties is presented. On the basis of this model, the global illumination equation is generalised for the polarisation case and is resolved into volume integration. This allows us to obtain an expression for the Monte Carlo method local estimates and to use them for evaluation of light distribution in the scene with consideration of polarisation. The obtained mathematical model was implemented in the software environment using the example of a scene with its surfaces having both diffuse and regular components of reflection. The results presented in the article show that the calculation difference may reach 30 % when polarisation is taken into consideration as compared to standard modelling.

Myocardial Noncompaction

2018 ◽  
Vol 69 (8) ◽  
pp. 2209-2212
Author(s):  
Alexandru Radu Mihailovici ◽  
Vlad Padureanu ◽  
Carmen Valeria Albu ◽  
Venera Cristina Dinescu ◽  
Mihai Cristian Pirlog ◽  
...  
Keyword(s):  
Ventricular Arrhythmias ◽  
Specific Treatment ◽  
Left Ventricular ◽  
Left Ventricular Noncompaction ◽  
Ventricular Noncompaction ◽  
Genetic Transmission ◽  
Asymptomatic Patients ◽  
Increased Risk ◽  
Patients With Heart Failure

Left ventricular noncompaction is a primary cardiomyopathy with genetic transmission in the vast majority of autosomal dominant cases. It is characterized by the presence of excessive myocardial trabecularities that generally affect the left ventricle. In diagnosing this condition, echocardiography is the gold standard, although this method involves an increased risk of overdiagnosis and underdiagnosis. There are also uncertain cases where echocardiography is inconclusive, a multimodal approach is needed, correlating echocardiographic results with those obtained by magnetic resonance imaging. The clinical picture may range from asymptomatic patients to patients with heart failure, supraventricular or ventricular arrhythmias, thromboembolic events and even sudden cardiac death. There is no specific treatment of left ventricular noncompaction, but the treatment is aimed at preventing and treating the complications of the disease. We will present the case of a young patient with left ventricular noncompactioncardiomyopathy and highlight the essential role of transthoracic echocardiography in diagnosing this rare heart disease.

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