STOCHASTIC TRANSMISSION DYNAMICS OF COVID-19 WITHIN A DENSITY DEPENDENT POPULATION

10.33003/659 ◽  
2021 ◽  
Vol 5 (2) ◽  
pp. 567-573
Author(s):  
Lubem M. Kwaghkor ◽  
Stephen E. Onah ◽  
Ibrahim G. Basi ◽  
Theophilus Danjuma
Keyword(s):  
Distribution Function ◽  
Exponential Distribution ◽  
Severe Disease ◽  
The Elderly ◽  
Control Measures ◽  
Special Treatment ◽  
Susceptible Population ◽  
Density Dependent ◽  
Infected People ◽  
Population Sizes

Coronavirus diseases (COVID-19) is a respiratory disease. Most infected people are known to develop mild to moderate symptoms and recover without requiring special treatment except for those who have underlying medical conditions and the elderly have a higher risk of developing severe disease. This research is aimed at studying the probable spread of the COVID-19 virus within a completely susceptible density-dependent population using a modified exponential distribution function. The modified exponential distribution function was extended to include the Basic Reproduction Number which was computed using the Nigerian COVID-19 index cases from 27th February to 18th April, 2020 to be. Various interesting results were obtained for the including the time period for the spread for different population sizes. The duration of the spread of the virus is from 4 to 7 hours with an average of 5.5 hours. This indicates that, for one infectious person with  to enter a completely susceptible population of size , the virus can spread through the entire population in about  hours if no control measures are in place.

Zika Virus Infection in the Elderly: Possible Relationship with Guillain-Barré Syndrome

Gerontology ◽  
2016 ◽  
Vol 63 (3) ◽  
pp. 210-215 ◽  
Author(s):  
Wilson Savino ◽  
Carolina V. Messias ◽  
Daniella A. Mendes-da-Cruz ◽  
Pamela Passos ◽  
Ana Carolina A.F. Ferreira ◽  
...  
Keyword(s):  
Zika Virus ◽  
Severe Disease ◽  
The Elderly ◽  
French Polynesia ◽  
Therapeutic Interventions ◽  
Guillain Barre Syndrome ◽  
Zikv Infection ◽  
Susceptible Population ◽  
Guillain Barré Syndrome ◽  
Guillain Barré

The Zika virus (ZIKV) outbreak in French Polynesia, in 2013, and in Brazil, in 2015, was correlated with neurological complications, which comprised, among others, congenital microcephaly and Guillain-Barré syndrome (GBS), which includes a group of acute autoimmune neuropathies generally reported after respiratory or gastrointestinal infectious diseases. Despite being relatively rare, the incidence rate of GBS rises with age, which makes GBS more frequent in the elderly, in whom it is also a more severe disease with slower recovery than in younger patients. Different forms of GBS have been described having diagnostic confirmation of a previous infection with the ZIKV virus. Although we do not have enough evidence that elderly people are a particularly susceptible population to developing GBS following ZIKV infection, this is plausible. We should consider this possibility, particularly taking into account that aging subjects are more susceptible to infections. In this context, a deeper understanding of how the immune system in the elderly functions in relation to ZIKV infection is necessary, as well as an understanding of what kind of alterations of the nervous system such an infection triggers in the elderly, beyond GBS. This will be relevant for better therapeutic interventions and for designing vaccine candidates that can be applied in an aging population, particularly those prone to develop ZIKV-induced autoimmunity.

scholarly journals The burden of seasonal influenza in Italy: a systematic review of influenza-related complications, hospitalizations, and mortality

2021 ◽  
Author(s):  
Irene Giacchetta ◽  
Chiara Primieri ◽  
Riccardo Cavalieri ◽  
Alexander Domnich ◽  
Chiara de Waure
Keyword(s):  
Seasonal Influenza ◽  
Risk Groups ◽  
The Elderly ◽  
Control Measures ◽  
Italian Population ◽  
Infected People ◽  
Public Health Decision ◽  
Increased Risk ◽  
Health Decision ◽  
Prevention And Control Measures

Background: reliable country-specific data on influenza burden play a crucial role in informing prevention and control measures. Our purpose was to provide a comprehensive summary of the available evidence on the burden of seasonal influenza in Italy. Methods: we performed a sys-tematic literature review of articles published until 31 July 2020. PubMed, Embase and Web of Science were searched using terms related to burden, influenza, and Italian population. We in-cluded studies investigating seasonal influenza-related complications, hospitalizations and/or mortality. Results: sixteen studies were included: eight (50%) analyzed influenza-related compli-cations, eight (50%) hospitalizations, while seven (43.8%) influenza-related deaths. Only three studies (19.7%) concerned pediatric age. The synthesis of results showed that patients with chron-ic conditions have an increased risk for complications up to almost three times as compared to healthy people. Hospitalizations due to influenza can occur in as much as 5% of infected people depending on the study setting. Excess deaths rates were over six-fold higher in the elderly as compared to the rest of population. Conclusions: although there are still gaps in existing data, there is evidence of the significant burden that influenza places each year especially on high-risk groups. These data should be used to inform public health decision-making.

scholarly journals Determination of critical community size from an HIV/AIDS model

PLoS ONE ◽  
2021 ◽  
Vol 16 (1) ◽  
pp. e0244543
Author(s):  
Sarmistha Das ◽  
Pramit Ghosh ◽  
Sandip Banerjee ◽  
Saumyadipta Pyne ◽  
Joydev Chattopadhyay ◽  
...  
Keyword(s):  
Control Strategies ◽  
Control Measures ◽  
Community Size ◽  
Hiv Model ◽  
Susceptible Population ◽  
Small Communities ◽  
Population Sizes ◽  
Random Variability ◽  
Systematic Control

After an epidemic outbreak, the infection persists in a community long enough to engulf the entire susceptible population. Local extinction of the disease could be possible if the susceptible population gets depleted. In large communities, the tendency of eventual damp down of recurrent epidemics is balanced by random variability. But, in small communities, the infection would die out when the number of susceptible falls below a certain threshold. Critical community size (CCS) is considered to be the mentioned threshold, at which the infection is as likely as not to die out after a major epidemic for small communities unless reintroduced from outside. The determination of CCS could aid in devising systematic control strategies to eradicate the infectious disease from small communities. In this article, we have come up with a simplified computation based approach to deduce the CCS of HIV disease dynamics. We consider a deterministic HIV model proposed by Silva and Torres, and following Nåsell, introduce stochasticity in the model through time-varying population sizes of different compartments. Besides, Metcalf’s group observed that the relative risk of extinction of some infections on islands is almost double that in the mainlands i.e. infections cease to exist at a significantly higher rate in islands compared to the mainlands. They attributed this phenomenon to the greater recolonization in the mainlands. Interestingly, the application of our method on demographic facts and figures of countries in the AIDS belt of Africa led us to expect that existing control measures and isolated locations would assist in temporary eradication of HIV infection much faster. For example, our method suggests that through systematic control strategies, after 7.36 years HIV epidemics will temporarily be eradicated from different communes of island nation Madagascar, where the population size falls below its CCS value, unless the disease is reintroduced from outside.

Acquired haemophilia in the elderly is a severe disease: report of five new cases

Haemophilia ◽  
2001 ◽  
Vol 7 (4) ◽  
pp. 428-432 ◽  
Author(s):  
S. Godreuil ◽  
R. Navarro ◽  
P. Quittet ◽  
L. Landreau ◽  
J-F. Schved ◽  
...  
Keyword(s):  
Severe Disease ◽  
The Elderly ◽  
Acquired Haemophilia

The Approximation of Sum of Independent Distributions by the Erlang Distribution Function

2002 ◽  
Vol 7 (1) ◽  
pp. 55-60 ◽  
Author(s):  
Antanas Karoblis
Keyword(s):  
Distribution Function ◽  
Exponential Distribution ◽  
Queueing Theory ◽  
Erlang Distribution ◽  
Estimation Of Error

The exponential distribution and the Erlang distribution function are been used in numerous areas of mathematics, and specifically in the queueing theory. Such and similar applications emphasize the importance of estimation of error of approximation by the Erlang distribution function. The article gives an analysis and technique of error’s estimation of an accuracy of such approximation, especially in some specific cases.

MALIGNANT MELANOMA. EPIDEMIOLOGY, ANALYTICAL INDICATORS OF THE EFFECTIVENESS OF ONCOLOGICAL SERVICES (POPULATION-BASED STUDY)

2017 ◽  
Vol 63 (2) ◽  
pp. 221-233
Author(s):  
Vakhtang Merabishvili
Keyword(s):  
Malignant Melanoma ◽  
Malignant Tumors ◽  
The Elderly ◽  
Population Based ◽  
Special Treatment ◽  
Detailed Structure ◽  
Population Based Study ◽  
Early Stages ◽  
One Year ◽  
Melanoma Epidemiology

Malignant melanoma of the skin (MMS) is less than 2% (1.74%) among all malignant tumors in Russia but this is more than 10,000 (10236-2015) of new cases. It is important to monitor the trend in dynamics of morbidity and mortality from this cause. From 1995 to 2015 a number of MMS primary cases was more than doubled in absolute numbers and “crude” rates. A slightly smaller increase is indicated by standardized indicators - 62.5% for men and 70.2% for women. Annually in Russia 3670 people die from MMS (2015), which is 1.2% of all cancer deaths. In recent years the previously revealed regularities have been largely preserved: lower rates of specific gravity detected in the early stages among people in the elderly and senile and in a smaller proportion in this group who received special treatment. At the same time a change in the detailed structure of the incidence of women has been revealed where currently the leading localization of MMS was not the lower extremities but the back. The index accuracy improved however the official statistics of the distribution of patients by stages of a disease was significantly distorted (weight of the early stages was increased from the real values). The index of one-year lethality and survival was significantly improved.

scholarly journals Human Coronaviruses: Counteracting the Damage by Storm

Viruses ◽  
2021 ◽  
Vol 13 (8) ◽  
pp. 1457
Author(s):  
Dewald Schoeman ◽  
Burtram C. Fielding
Keyword(s):  
Immune Response ◽  
Severe Disease ◽  
Antiviral Agents ◽  
The Elderly ◽  
Highly Pathogenic ◽  
Vaccine Responses ◽  
Cell Mediated Immune Response ◽  
Inhibition Antibody ◽  
A Cell ◽  
Human Coronaviruses

Over the past 18 years, three highly pathogenic human (h) coronaviruses (CoVs) have caused severe outbreaks, the most recent causative agent, SARS-CoV-2, being the first to cause a pandemic. Although much progress has been made since the COVID-19 pandemic started, much about SARS-CoV-2 and its disease, COVID-19, is still poorly understood. The highly pathogenic hCoVs differ in some respects, but also share some similarities in clinical presentation, the risk factors associated with severe disease, and the characteristic immunopathology associated with the progression to severe disease. This review aims to highlight these overlapping aspects of the highly pathogenic hCoVs—SARS-CoV, MERS-CoV, and SARS-CoV-2—briefly discussing the importance of an appropriately regulated immune response; how the immune response to these highly pathogenic hCoVs might be dysregulated through interferon (IFN) inhibition, antibody-dependent enhancement (ADE), and long non-coding RNA (lncRNA); and how these could link to the ensuing cytokine storm. The treatment approaches to highly pathogenic hCoV infections are discussed and it is suggested that a greater focus be placed on T-cell vaccines that elicit a cell-mediated immune response, using rapamycin as a potential agent to improve vaccine responses in the elderly and obese, and the potential of stapled peptides as antiviral agents.

scholarly journals Considerations for a Respiratory Syncytial Virus Vaccine Targeting an Elderly Population

Vaccines ◽  
2021 ◽  
Vol 9 (6) ◽  
pp. 624
Author(s):  
Laura M. Stephens ◽  
Steven M. Varga
Keyword(s):  
Respiratory Syncytial Virus ◽  
Disease Burden ◽  
Elderly Population ◽  
Vaccine Development ◽  
The Elderly ◽  
The United States ◽  
Susceptible Population ◽  
Age Related ◽  
Syncytial Virus ◽  
Tract Infections

Respiratory syncytial virus (RSV) is most commonly associated with acute lower respiratory tract infections in infants and children. However, RSV also causes a high disease burden in the elderly that is often under recognized. Adults >65 years of age account for an estimated 80,000 RSV-associated hospitalizations and 14,000 deaths in the United States annually. RSV infection in aged individuals can result in more severe disease symptoms including pneumonia and bronchiolitis. Given the large disease burden caused by RSV in the aged, this population remains an important target for vaccine development. Aging results in lowered immune responsiveness characterized by impairments in both innate and adaptive immunity. This immune senescence poses a challenge when developing a vaccine targeting elderly individuals. An RSV vaccine tailored towards an elderly population will need to maximize the immune response elicited in order to overcome age-related defects in the immune system. In this article, we review the hurdles that must be overcome to successfully develop an RSV vaccine for use in the elderly, and discuss the vaccine candidates currently being tested in this highly susceptible population.

scholarly journals Neutrophils in respiratory viral infections

2021 ◽  
Author(s):  
Cecilia Johansson ◽  
Freja C. M. Kirsebom
Keyword(s):  
Viral Infections ◽  
Immune Cell ◽  
Respiratory Infections ◽  
Fungal Infections ◽  
Severe Disease ◽  
The Elderly ◽  
Viral Control ◽  
Immunological Mechanisms ◽  
Respiratory Viral Infections ◽  
Viral Respiratory Infections

AbstractViral respiratory infections are a common cause of severe disease, especially in infants, people who are immunocompromised, and in the elderly. Neutrophils, an important innate immune cell, infiltrate the lungs rapidly after an inflammatory insult. The most well-characterized effector mechanisms by which neutrophils contribute to host defense are largely extracellular and the involvement of neutrophils in protection from numerous bacterial and fungal infections is well established. However, the role of neutrophils in responses to viruses, which replicate intracellularly, has been less studied. It remains unclear whether and, by which underlying immunological mechanisms, neutrophils contribute to viral control or confer protection against an intracellular pathogen. Furthermore, neutrophils need to be tightly regulated to avoid bystander damage to host tissues. This is especially relevant in the lung where damage to delicate alveolar structures can compromise gas exchange with life-threatening consequences. It is inherently less clear how neutrophils can contribute to host immunity to viruses without causing immunopathology and/or exacerbating disease severity. In this review, we summarize and discuss the current understanding of how neutrophils in the lung direct immune responses to viruses, control viral replication and spread, and cause pathology during respiratory viral infections.

scholarly journals Upaya Penanganan Khusus Narapidana Lansia sebagai Kelompok Rentan

2021 ◽  
Vol 1 (12) ◽  
pp. 855-867
Author(s):  
Elika Sifra Lidya ◽  
Mitro Subroto
Keyword(s):  
Justice System ◽  
Health Workers ◽  
The Elderly ◽  
Vulnerable Groups ◽  
Special Treatment ◽  
Correctional Institution ◽  
Correctional Services ◽  
The Social ◽  
Directorate General ◽  
The Government

LAPAS or Correctional Institution under the auspices of the Directorate General of Corrections is the final place of the criminal justice system process that fosters and integrates the social of convicts, so that when returning to society they are able to live a normal life. Elderly (according to Law No. 13 of 1998: Elderly) is a person whose age reaches the age of 60 years and above. In its efforts, Correctional Services interpret this understanding by regulating the rights of inmates contained in Law no. 12 of 1995 article 14 paragraph 1.The increasing age and declining body condition of the elderly inmates need special treatment both in health, treatment, and public services. Elderly inmates as much as possible are treated as people usually are, it's just that the place and application are different. This is for the implementation of part of Human Rights (HAM) as a national instrument. This special handling effort involves other stakeholders be it medical or health workers and the government to support the infrastructure needed. The elderly as one of the vulnerable groups become important objects in terms of how decent handlers are so that they feel cared for in their twilight years. Although until now still in the process and stages of refinement of special handling for them. The fact is still not optimal and this study illustrates how well the effort is.

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