scholarly journals Inferring age-specific differences in susceptibility to and infectiousness upon SARS-CoV-2 infection based on Belgian social contact data

2021 ◽  
Author(s):  
Nicolas Franco ◽  
Pietro Coletti ◽  
Lander Willem ◽  
Leonardo Angeli ◽  
Adrien Lajot ◽  
...  
Keyword(s):  
Vaccination Campaign ◽  
Real Life ◽  
Social Contact ◽  
The Elderly ◽  
Computational Tools ◽  
Incidence Data ◽  
Transmission Parameters ◽  
Very Young Children ◽  
Age Related ◽  
Contact Data

Several important aspects related to SARS-CoV-2 transmission are not well known due to a lack of appropriate data. However, mathematical and computational tools can be used to extract part of this information from the available data, like some hidden age-related characteristics. In this paper, we investigate age-specific differences in susceptibility to and infectiousness upon contracting SARS-CoV-2 infection. More specifically, we use panel-based social contact data from diary-based surveys conducted in Belgium combined with the next generation principle to infer the relative incidence and we compare this to real-life incidence data. Comparing these two allows for the estimation of age-specific transmission parameters. Our analysis implies the susceptibility in children to be around half of the susceptibility in adults, and even lower for very young children (preschooler). However, the probability of adults and the elderly to contract the infection is decreasing throughout the vaccination campaign, thereby modifying the picture over time.

scholarly journals Cohort-based Smoothing Methods for Age-specific Contact Rates

2018 ◽  
Author(s):  
Yannick Vandendijck ◽  
Carlo G. Camarda ◽  
Niel Hens
Keyword(s):  
Disease Transmission ◽  
Age Distribution ◽  
Social Contact ◽  
Population Based ◽  
Smoothing Methods ◽  
Transmission Parameters ◽  
Contact Rates ◽  
The Social ◽  
Specific Contact ◽  
Contact Data

AbstractThe use of social contact rates is widespread in infectious disease modelling, since it is known that they provide proxies of crucial determinants of epidemiological and disease transmission parameters. Information on social contact rates can, for example, be obtained from a population-based contact diary survey, such as the POLYMOD study. Estimation of age-specific contact rates from these studies is often done using bivariate smoothing techniques. Typically, smoothing is done in the dimensions of the respondent’s and contact’s age. In this paper, we introduce a smoothing constrained approach - taking into account the reciprocal nature of contacts - where the contact rates are assumed smooth from a cohort perspective as well as from the age distribution of contacts. This is achieved by smoothing over the diagonal components (including all subdiagonals) of the social contact matrix. This approach is supported by the fact that people age with time and thus contact rates should vary smoothly by cohorts. Two approaches that allow for smoothing of social contact data over cohorts are proposed: (1) reordening of the diagonal components of the social contact rate matrix; and (2) reordening of the penalty matrix associated with the diagonal components. Parameter estimation is done using constrained penalized iterative reweighted least squares. A simulation study is presented to compare methods. The proposed methods are illustrated on the Belgian POLYMOD data of 2006.

scholarly journals Impact of personalized-dose vaccination in Covid-19 with a limited vaccine supply in a 100 day period in the U.S.A.

2021 ◽  
Author(s):  
Patrick Hunziker
Keyword(s):  
Protective Efficacy ◽  
Social Contact ◽  
Vaccination Strategy ◽  
The Elderly ◽  
Rapid Reduction ◽  
Vaccination Strategies ◽  
Age Related ◽  
The Usa ◽  
Dosing Strategies ◽  
The Individual

AbstractBackgroundWe aimed at minimizing loss of lives in the Covid-19 pandemic in the USA by identifying optimal vaccination strategies during a 100-day period with limited vaccine supplies. While lethality is highest in the elderly, transmission and case numbers are highest in the younger. A strategy of first vaccinating the elderly is widely used, thought to protect the vulnerable, elderly best. Despite lower immunogenicity in the elderly, mRNA vaccines retain high efficacy, implying that in the younger, reduced vaccine doses might suffice, thereby increasing vaccination counts with a given vaccine supply.MethodsUsing published immunogenicity data of the Moderna mRNA-1273 vaccine, we examined the value of personalized-dose vaccination strategies, using a modeling approach incorporating age-related vaccine immunogenicity, social contact patterns, population structure, Covid-19 case and death rates in the USA in late January 2021. An increase if the number of persons that can be vaccinated and a potential reduction of the individual protective efficacy was accounted for.ResultsAge-personalized dosing strategies reduced cases faster, shortening the pandemic, reducing the delay to reaching <100’000 cases/day from 64 to 30 days and avoiding 25’000 deaths within 100 days in the USA. In an “elderly first” vaccination strategy, mortality is higher even in the elderly. Findings were robust with transmission blocking efficacies of reduced dose vaccination between 30% to 90%, and with a vaccine supply from 1 to 3 million full dose vaccinations per day.ConclusionRapid reduction of Covid-19 case and death rate in the USA in 100 days with a limited vaccine supply is best achieved when personalized, age-tailored dosing for highly effective vaccines is used, according to this vaccination strategy model parameterized to U.S. demographics, Covid-19 transmission and vaccine characteristics. Protecting the vulnerable is most effectively achieved by personalized-dose vaccination of all population segments, while an “elderly first” approach costs more lives, even in the elderly.

The Biological Clock and Sleep in the Elderly

2006 ◽  
Vol 19 (1) ◽  
pp. 45-51 ◽  
Author(s):  
Myriam Juda ◽  
Mirjam Münch ◽  
Anna Wirz-Justice ◽  
Martha Merrow ◽  
Till Roenneberg
Keyword(s):  
Circadian Rhythms ◽  
Biological Clock ◽  
The Elderly ◽  
Early Morning ◽  
Behavioral Changes ◽  
Older Age ◽  
Age Related ◽  
Theoretical Considerations ◽  
Sleep Difficulties ◽  
Circadian Biology

Abstract: Among many other changes, older age is characterized by advanced sleep-wake cycles, changes in the amplitude of various circadian rhythms, as well as reduced entrainment to zeitgebers. These features reveal themselves through early morning awakenings, sleep difficulties at night, and a re-emergence of daytime napping. This review summarizes the observations concerning the biological clock and sleep in the elderly and discusses the documented and theoretical considerations behind these age-related behavioral changes, especially with respect to circadian biology.

What Can We Learn from Sarcopenia with Curarisation in the Context of Cancer Surgery? A Review of the Literature

2019 ◽  
Vol 25 (28) ◽  
pp. 3005-3010
Author(s):  
Georges Samouri ◽  
Alexandre Stouffs ◽  
Lionel V. Essen ◽  
Olivier Simonet ◽  
Marc De Kock ◽  
...  
Keyword(s):  
Frail Elderly ◽  
Muscle Fibers ◽  
Motor Units ◽  
The Elderly ◽  
Hepatic Function ◽  
Volume Of Distribution ◽  
Neuromuscular Blocking ◽  
Cancer Surgery ◽  
Old People ◽  
Age Related

Introduction: The monitoring of the curarisation is a unique opportunity to investigate the function of the neuromuscular junction (NMJ) during cancer surgery, especially in frailty-induced and age-related sarcopenia. Method: We conducted a comprehensive literature review in PubMed, without any limit of time related to frailty, sarcopenia, age and response to neuromuscular blockers in the context of cancer surgery. Results: Several modifications appear with age: changes in cardiac output, a decrease in muscle mass and increase in body fat, the deterioration in renal and hepatic function, the plasma clearance and the volume of distribution in elderly are smaller. These changes can be exacerbated in cancer patients. We also find modifications of the NMJ: dysfunctional mitochondria, modifications in the innervation of muscle fibers and motor units, uncoupling of the excitation-contraction of muscle fibers, inflammation. : Neuromuscular blocking agents (NMBAs) compete with acetylcholine and prevent it from fixing itself on its receptor. Many publications reported guidelines for using NMBAs in the elderly, based on studies comparing old people with young people. : No one screened frailty before, and thus, no studies compared frail elderly and non-frail elderly undergoing cancer surgery. Conclusion: Despite many studies about curarisation in the specific populations, and many arguments for a potential interest for investigation, no studies investigated specifically the response to NMBAs in regard of the frailty-induced and age-related sarcopenia.

scholarly journals A Narrative Review on Sarcopenia in Type 2 Diabetes Mellitus: Prevalence and Associated Factors

Nutrients ◽  
2021 ◽  
Vol 13 (1) ◽  
pp. 183
Author(s):  
Anna Izzo ◽  
Elena Massimino ◽  
Gabriele Riccardi ◽  
Giuseppe Della Pepa
Keyword(s):  
Diabetes Mellitus ◽  
Type 2 Diabetes ◽  
Type 2 Diabetes Mellitus ◽  
Elderly Population ◽  
The Elderly ◽  
Narrative Review ◽  
Macrovascular Complications ◽  
Diabetic Patients ◽  
Age Related

Type 2 diabetes mellitus (T2DM) represents a major health burden for the elderly population, affecting approximately 25% of people over the age of 65 years. This percentage is expected to increase dramatically in the next decades in relation to the increased longevity of the population observed in recent years. Beyond microvascular and macrovascular complications, sarcopenia has been described as a new diabetes complication in the elderly population. Increasing attention has been paid by researchers and clinicians to this age-related condition—characterized by loss of skeletal muscle mass together with the loss of muscle power and function—in individuals with T2DM; this is due to the heavy impact that sarcopenia may have on physical and psychosocial health of diabetic patients, thus affecting their quality of life. The aim of this narrative review is to provide an update on: (1) the risk of sarcopenia in individuals with T2DM, and (2) its association with relevant features of patients with T2DM such as age, gender, body mass index, disease duration, glycemic control, presence of microvascular or macrovascular complications, nutritional status, and glucose-lowering drugs. From a clinical point of view, it is necessary to improve the ability of physicians and dietitians to recognize early sarcopenia and its risk factors in patients with T2DM in order to make appropriate therapeutic approaches able to prevent and treat this condition.

Aflibercept in real-life for the treatment of age-related macular degeneration using a treat and extend protocol: The Armada study

2021 ◽  
pp. 112067212110057
Author(s):  
Pierre Gascon ◽  
Prithvi Ramtohul ◽  
Charles Delaporte ◽  
Sébastien Kerever ◽  
Danièle Denis ◽  
...  
Keyword(s):  
Macular Degeneration ◽  
Real Life ◽  
Age Related Macular Degeneration ◽  
Cumulative Number ◽  
Treat And Extend ◽  
Treatment Interval ◽  
Age Related ◽  
Treatment Naïve ◽  
The Mean

Purpose: To report the visual and anatomic outcomes in treatment-naïve neovascular age-related macular degeneration (nAMD) patients treated with aflibercept under a standardized Treat and Extend (T&E) protocol for up to 3 years of follow-up in “real-life” practice. Methods: This retrospective, observational, multicenter study included patients with treatment-naïve nAMD and at least 12 months of follow-up. T&E regimen adjustment was initiated after loading phase. At each visit best-corrected visual acuity (BCVA) and optical coherence tomography parameters were performed. Results: One hundred and thirty-six eyes of 115patients had at least 1 year of follow-up with 114 and 82 eyes completing at least 2 and 3 years of follow-up, respectively (mean follow-up duration: 2.7 ± 1.3 years). Mean age was 78.6 ± 8.6 years old and 52% were women. Mean BCVA increased from 60.6 ± 18.7 letters at diagnosis to 66.9 ± 16.2 letters at 1 year (+6.3 letters, p = 0.003) and remained stable throughout the follow-up period (63.1 ± 20.3 letters (+2.5, p = 0.1) and 64.0 ± 20.1 letters (+3.4, p = 0.27) at 2 and 3 years, respectively). The mean central retinal thickness decreased significantly from 358.2 ± 87.9 µm at baseline to 302 ± 71.7 µm at 12 months and maintained stable after 36 months of follow-up (297.1 ± 76 µm, p < 0.0001). Mean number of injections was 6.6 ± 2.2, 4.8 ± 1.9, and 5.6 ± 1.7 at 1, 2, and 3 years, respectively. Mean cumulative number of 16.4 ± 5.6 injections after 3 years. Mean treatment interval was 6.8 ± 2.5 weeks at 1 year. Eight-week and 12-week treatment interval were achieved in 59.5% and 19.1%, 65.8%, and 36.8% and 69.5% and 41.5% at 1, 2, and 3 years, respectively. Conclusions: Our study demonstrated that intravitreal injections of aflibercept initiated under a standardized T&E for patients with treatment-naïve nAMD allow for significant visual improvement at 12 months, which was maintained over a 3-year follow-up period.

scholarly journals Corticobasal Degeneration Misdiagnosed As Musculoskeletal Disease: A Challenging Diagnosis of Higher-Level Gait Disease

2020 ◽  
Vol 11 (04) ◽  
pp. 640-642
Author(s):  
Halil Onder
Keyword(s):  
Corticobasal Degeneration ◽  
The Elderly ◽  
Gait Disorders ◽  
Physiological Changes ◽  
Gait Abnormality ◽  
Age Related ◽  
Musculoskeletal Problems ◽  
Neurological Exam ◽  
Long Time ◽  
High Level

AbstractGait disorders are common in the elderly as there are various causes of neurological and non-neurological conditions. On the other hand, most of the gait parameters do change with advancing age which is identified as age-related physiological changes in gait. At this point, the discrimination between age-related physiological changes and gait disorders may be strictly challenging. After identifying gait as an abnormal pattern, classification of it and making the responsible pathophysiology also require high-level expertise in this regard. Herein, we present a rare patient with corticobasal degeneration (CBD) who had admitted initially due to complaints of gait problems. Over a long time, the patient had received the misdiagnosis of gait abnormality due to musculoskeletal problems by multiple physicians. However, the detailed neurological exam showed a higher level gait disorder (HLGD). Further investigations at this point yielded the diagnosis of CBD.

scholarly journals Impact of neovascular age-related macular degeneration: burden of patients receiving therapies in Japan

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Shigeru Honda ◽  
Yasuo Yanagi ◽  
Hideki Koizumi ◽  
Yirong Chen ◽  
Satoru Tanaka ◽  
...  
Keyword(s):  
Macular Degeneration ◽  
Productivity Loss ◽  
Work Productivity ◽  
The Elderly ◽  
Developed Countries ◽  
Age Related Macular Degeneration ◽  
Resource Utilisation ◽  
Total Work ◽  
Healthcare Resource Utilisation ◽  
Age Related

AbstractThe chronic eye disorder, neovascular age-related macular degeneration (nAMD), is a common cause of permanent vision impairment and blindness among the elderly in developed countries, including Japan. This study aimed to investigate the disease burden of nAMD patients under treatment, using data from the Japan National Health and Wellness surveys 2009–2014. Out of 147,272 respondents, 100 nAMD patients reported currently receiving treatment. Controls without nAMD were selected by 1:4 propensity score matching. Healthcare Resource Utilisation (HRU), Health-Related Quality of Life (HRQoL), and work productivity loss were compared between the groups. Regarding HRU, nAMD patients had significantly increased number of visits to any healthcare provider (HCP) (13.8 vs. 8.2), ophthalmologist (5.6 vs. 0.8), and other HCP (9.5 vs. 7.1) compared to controls after adjusting for confounding factors. Additionally, nAMD patients had reduced HRQoL and work productivity, i.e., reduced physical component summary (PCS) score (46.3 vs. 47.9), increased absenteeism (18.14% vs. 0.24%), presenteeism (23.89% vs. 12.44%), and total work productivity impairment (33.57% vs. 16.24%). The increased number of ophthalmologist visits were associated with decreased PCS score, increased presenteeism and total work productivity impairment. The current study highlighted substantial burden for nAMD patients, requiring further attention for future healthcare planning and treatment development.

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 A data-driven metapopulation model for the Belgian COVID-19 epidemic: assessing the impact of lockdown and exit strategies

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Pietro Coletti ◽  
Pieter Libin ◽  
Oana Petrof ◽  
Lander Willem ◽  
Steven Abrams ◽  
...  
Keyword(s):  
Phase 1 ◽  
Leisure Activities ◽  
National Level ◽  
Social Contact ◽  
Exit Strategy ◽  
Initial Wave ◽  
Contact Data ◽  
Stochastic Data ◽  
The Impact ◽  
Second Wave

Abstract Background In response to the ongoing COVID-19 pandemic, several countries adopted measures of social distancing to a different degree. For many countries, after successfully curbing the initial wave, lockdown measures were gradually lifted. In Belgium, such relief started on May 4th with phase 1, followed by several subsequent phases over the next few weeks. Methods We analysed the expected impact of relaxing stringent lockdown measures taken according to the phased Belgian exit strategy. We developed a stochastic, data-informed, meta-population model that accounts for mixing and mobility of the age-structured population of Belgium. The model is calibrated to daily hospitalization data and is able to reproduce the outbreak at the national level. We consider different scenarios for relieving the lockdown, quantified in terms of relative reductions in pre-pandemic social mixing and mobility. We validate our assumptions by making comparisons with social contact data collected during and after the lockdown. Results Our model is able to successfully describe the initial wave of COVID-19 in Belgium and identifies interactions during leisure/other activities as pivotal in the exit strategy. Indeed, we find a smaller impact of school re-openings as compared to restarting leisure activities and re-openings of work places. We also assess the impact of case isolation of new (suspected) infections, and find that it allows re-establishing relatively more social interactions while still ensuring epidemic control. Scenarios predicting a second wave of hospitalizations were not observed, suggesting that the per-contact probability of infection has changed with respect to the pre-lockdown period. Conclusions Contacts during leisure activities are found to be most influential, followed by professional contacts and school contacts, respectively, for an impending second wave of COVID-19. Regular re-assessment of social contacts in the population is therefore crucial to adjust to evolving behavioral changes that can affect epidemic diffusion.

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