scholarly journals A simulation study on the relative role of age groups under differing pertussis transmission scenarios

2018 ◽  
Author(s):  
Ana I. Bento ◽  
Aaron A. King ◽  
Pejman Rohani
Keyword(s):  
Herd Immunity ◽  
Age Groups ◽  
Transmission Model ◽  
Relative Role ◽  
Older Individuals ◽  
Age Cohorts ◽  
Relative Risks ◽  
Transmission Mechanisms ◽  
Acellular Vaccines ◽  
The Impact

AbstractPertussis has resurged in many countries where it was once regarded as under control, with the recent outbreaks showing a shift in incidence towards teens and older individuals. Here, using an age-stratified transmission model, we tested two potential causes for underlying changes in pertussis transmission dynamics. We did so assuming hypothesized mechanisms supporting present-day pertussis epidemiology: (I) improved diagnostics, (II) acellular vaccines leading to asymptomatic transmission (III) both. We used the relative risks and odds ratio methods to examine the impact of these differing assumptions on signatures of relative roles of key age groups through time, allowing us to explore those age cohorts that disproportionately account for transmission. Our findings show that for epidemics after the vaccine switch, a scenario with increased adult reporting and no asymptomatic transmission reflect a loss of signal, where no age group appears to be key. While scenarios with asymptomatic transmission, reflect a population where children (1-10 years old) are still disproportionally at risk. These results demonstrate that understanding the underlying transmission mechanisms in a population are paramount for vaccination policies in attaining herd immunity and eventually eradication.

scholarly journals Vaccinating Adolescents and Children Significantly Reduces COVID-19 Morbidity and Mortality across All Ages: A Popula-Tion-Based Modeling Study Using the UK as an Example

Vaccines ◽  
2021 ◽  
Vol 9 (10) ◽  
pp. 1180
Author(s):  
Tinevimbo Shiri ◽  
Marc Evans ◽  
Carla A. Talarico ◽  
Angharad R. Morgan ◽  
Maaz Mussad ◽  
...  
Keyword(s):  
Disease Transmission ◽  
Age Groups ◽  
Population Level ◽  
Vital Role ◽  
Morbidity And Mortality ◽  
Transmission Model ◽  
Base Case ◽  
Global Public Health ◽  
The Uk ◽  
The Impact

Debate persists around the risk–benefit balance of vaccinating adolescents and children against COVID-19. Central to this debate is quantifying the contribution of adolescents and children to the transmission of SARS-CoV-2, and the potential impact of vaccinating these age groups. In this study, we present a novel SEIR mathematical disease transmission model that quantifies the impact of different vaccination strategies on population-level SARS-CoV-2 infections and clinical outcomes. The model employs both age- and time-dependent social mixing patterns to capture the impact of changes in restrictions. The model was used to assess the impact of vaccinating adolescents and children on the natural history of the COVID-19 pandemic across all age groups, using the UK as an example. The base case model demonstrates significant increases in COVID-19 disease burden in the UK following a relaxation of restrictions, if vaccines are limited to those ≥18 years and vulnerable adolescents (≥12 years). Including adolescents and children in the vaccination program could reduce overall COVID-related mortality by 57%, and reduce cases of long COVID by 75%. This study demonstrates that vaccinating adolescents and children has the potential to play a vital role in reducing SARS-CoV-2 infections, and subsequent COVID-19 morbidity and mortality, across all ages. Our results have major global public health implications and provide valuable information to inform a potential pandemic exit strategy.

scholarly journals Modelling control measures to reduce the impact of pandemic influenza among schoolchildren

2007 ◽  
Vol 136 (8) ◽  
pp. 1035-1045 ◽  
Author(s):  
S.-C. CHEN ◽  
C.-M. LIAO
Keyword(s):  
Elementary School ◽  
Pandemic Influenza ◽  
Age Groups ◽  
Integrated Approach ◽  
Control Measures ◽  
Transmission Model ◽  
Transmission Potential ◽  
Vaccination Coverage Rate ◽  
Control Programmes ◽  
The Impact

SUMMARYWe coupled the Wells–Riley equation and the susceptible–exposed–infected–recovery (SEIR) model to quantify the impact of the combination of indoor air-based control measures of enhanced ventilation and respiratory masking in containing pandemic influenza within an elementary school. We integrated indoor environmental factors of a real elementary school and aetiological characteristics of influenza to estimate the age-specific risk of infection (P) and basic reproduction number (R0). We combined the enhanced ventilation rates of 0·5, 1, 1·5, and 2/h and respiratory masking with 60%, 70%, 80%, and 95% efficacies, respectively, to predict the reducing level of R0. We also took into account the critical vaccination coverage rate among schoolchildren. Age-specific P and R0 were estimated respectively to be 0·29 and 16·90; 0·56 and 16·11; 0·59 and 12·88; 0·64 and 16·09; and 0·07 and 2·80 for five age groups 4–6, 7–8, 9–10, 11–12, and 25–45 years, indicating pre-schoolchildren have the highest transmission potential. We conclude that our integrated approach, employing the mechanism of transmission of indoor respiratory infection, population-dynamic transmission model, and the impact of infectious control programmes, is a powerful tool for risk profiling prediction of pandemic influenza among schoolchildren.

scholarly journals 2715. Pneumococcal Community-Acquired Pneumonia Attributed to PCV13 Serotypes in Hospitalized Adults: Comparison of the 50–64 and 65+ Age Groups

2019 ◽  
Vol 6 (Supplement_2) ◽  
pp. S955-S955
Author(s):  
Jason J LeBlanc ◽  
May ElSherif ◽  
Lingyun Ye ◽  
Donna MacKinnon-Cameron ◽  
Ardith Ambrose ◽  
...  
Keyword(s):  
Herd Immunity ◽  
Age Groups ◽  
Outcome Data ◽  
Community Acquired Pneumonia ◽  
Childhood Immunization ◽  
Age Cohorts ◽  
Vaccine Type ◽  
Age Cohort ◽  
Canadian Provinces ◽  
Quellung Reaction

Abstract Background In healthy adults aged ≥65 years, direct immunization with the 13-valent pneumococcal conjugate vaccine (PCV13) was shown effective at preventing vaccine-type pneumococcal community-acquired pneumonia (pCAP) and invasive pneumococcal disease (IPD). Although PCV13 was licensed for use in Canadian adults aged >50 years, it was recommended for immunocompromised individuals who are at highest risk of IPD. In 2016, a recommendation was issued for use of PCV13 in immunocompetent adults aged ≥65 years, for the prevention of pCAP and IPD. This study aimed to compare pCAP cases attributed to PCV13 serotypes in adults aged 50–64 and ≥65 years. Methods Active surveillance for CAP and IPD was performed from 2010 to 2015 in adult hospitals across five Canadian provinces. To identify pCAP, blood culture, sputum culture, or a PCV13 serotype-specific urine antigen detection (ssUAD) were used. Serotype was assigned using Quellung reaction, PCR, or ssUAD. All pCAP cases were categorized by serotype and age groups. Patient demographics and outcome data were collected. Results Over years 2010–2015, 6687 CAP cases were tested. 835 pCAP cases were identified, of which 418 (50%) caused by a PCV13 serotype. The majority (74%) of PCV13-associated pCAP occurred in the adults aged ≥50 years, whereas only 41.4% (173/418) were in adults ≥65 years. PCV13 pCAP cases declined over the years, likely through herd immunity from childhood immunization. The yearly proportion of pCAP attributed to PCV13 serotypes for ages ≥50 remained high (67.5 to 80.6%), compared those occurring in the ≥65 age groups (35.1 to 49.4%). Compared with test-negative controls, pCAP cases in both age groups were more likely to be admitted to ICU, require mechanical ventilation, and had higher mortality. Of pCAP deaths, 61.4% and 82.3% were in the ≥65 and ≥50 age cohorts, respectively. Conclusion From year 2010 to 2015, adults hospitalized with PCV13 pCAP in the ≥65 age cohort accounted for less than half of the cases, whereas including the 50–64 age cohort increased the proportion to 74%. Similarly, the proportion of PCV13 pCAP deaths that occurred in adults aged ≥50 years was 82%, compared with 61% in the ≥65 age cohort. Expansion of PCV13 recommendations to include adults 50–64 years of age should be considered. Disclosures All authors: No reported disclosures.

Traumatic Stress in Older Adults

2012 ◽  
pp. 118-127
Author(s):  
Joan M. Cook ◽  
Tatyana Biyanova ◽  
Diane L. Elmore
Keyword(s):  
Older Adults ◽  
World War Ii ◽  
Functional Impairment ◽  
Stress Disorder ◽  
Acute Stress ◽  
Age Groups ◽  
Care Utilization ◽  
Older Individuals ◽  
Delayed Recognition ◽  
The Impact

This chapter focuses on older adult trauma survivors. Information is presented on prevalence of acute stress disorder (ASD) and posttraumatic stress disorder (PTSD); course, functional impairment, suicide risk, and health care utilization in older adults with PTSD; and the impact of demographic factors such as gender, ethnicity, and race on PTSD in older individuals. In general, rates of ASD and PTSD are lower in older adults compared to other age groups. PTSD in older adults has been linked to suicidal ideation and attempts, functional impairment, physical health, and increased healthcare utilization. Although delayed onset of PTSD has been empirically verified in some military samples with World War II veterans and younger adult civilians, it is rare in the absence of any prior symptoms and might more accurately be labeled “delayed recognition.” More information on trauma and PTSD in diverse populations of older adults is needed, such as racial and ethnic minorities, those with severe physical or mental impairment, noncommunity-residing groups, and those from nonindustrialized countries.

Sedentary Habits, Health, and Function in Older Women and Men

2000 ◽  
Vol 15 (1) ◽  
pp. 1-8 ◽  
Author(s):  
Steven N. Blair ◽  
Ming Wei
Keyword(s):  
Data Extraction ◽  
Functional Limitations ◽  
Age Groups ◽  
Extraction Methods ◽  
Epidemiological Studies ◽  
Older Individuals ◽  
Loss Of Function ◽  
Relative Risks ◽  
Response Gradient ◽  
And Function

Purpose. To evaluate the relation of physical activity and cardiorespiratory fitness to morbidity, mortality, and functional limitations in older persons. Data Sources. We reviewed published reports related to the review's purpose. Sources were identified from recent major reports and position statements from scientific and public health organizations, our files, and reference lists of published papers. Study Inclusion and Exclusion Criteria. We included prospective epidemiological studies and clinical trials published in the peer-reviewed literature that included data from age groups of people 60 years and older. We evaluated study methods and included studies that used valid measures of exposures, clearly specified outcomes, and controlled for confounders. Data Extraction Methods. We extracted by detailed review data on sample characteristics, outcomes, and rates and relative risks. Data Synthesis. Extracted data were included in tables, figures, or the text and were synthesized by nonquantitative methods. Major Conclusions. Active and fit individuals were at much lower risk for morbidity, mortality, and loss of function when compared with sedentary and unfit persons. Data from the studies generally conformed to a steep inverse dose-response gradient across activity or fitness categories. Results were consistent, temporally appropriate, strong, and graded, and therefore support a causal hypothesis that a fit and active way of life improves health and function in older individuals.

scholarly journals Modelling the impact of extending dose intervals for COVID-19 vaccines in Canada

2021 ◽  
Author(s):  
Austin Nam ◽  
Raphael Ximenes ◽  
Man Wah Yeung ◽  
Sharmistha Mishra ◽  
Jianhong Wu ◽  
...  
Keyword(s):  
Time Horizon ◽  
Compartmental Model ◽  
Age Groups ◽  
Dose Interval ◽  
Base Case ◽  
Third Wave ◽  
Older Individuals ◽  
High Efficacy ◽  
The Impact ◽  
Epidemiologic Features

AbstractBackgroundDual dose SARS-CoV-2 vaccines demonstrate high efficacy and will be critical in public health efforts to mitigate the COVID-19 pandemic and its health consequences; however, many jurisdictions face very constrained vaccine supply. We examined the impacts of extending the interval between two doses of mRNA vaccines in Canada in order to inform deliberations of Canada’s National Advisory Committee on Immunization.MethodsWe developed an age-stratified, deterministic, compartmental model of SARS-CoV-2 transmission and disease to reproduce the epidemiologic features of the epidemic in Canada. Simulated vaccination comprised mRNA vaccines with explicit examination of effectiveness against disease (67% [first dose], 94% [second dose]), hospitalization (80% [first dose], 96% [second dose]), and death (85% [first dose], 96% [second dose]) in adults aged 20 years and older. Effectiveness against infection was assumed to be 90% relative to the effectiveness against disease. We used a 6-week mRNA dose interval as our base case (consistent with early program rollout across Canadian and international jurisdictions) and compared extended intervals of 12 weeks, 16 weeks, and 24 weeks. We began vaccinations on January 1, 2021 and simulated a third wave beginning on April 1, 2021.ResultsExtending mRNA dose intervals were projected to result in 12.1-18.9% fewer symptomatic cases, 9.5-13.5% fewer hospitalizations, and 7.5-9.7% fewer deaths in the population over a 12-month time horizon. The largest reductions in hospitalizations and deaths were observed in the longest interval of 24 weeks, though benefits were diminishing as intervals extended. Benefits of extended intervals stemmed largely from the ability to accelerate coverage in individuals aged 20-74 years as older individuals were already prioritized for early vaccination. Conditions under which mRNA dose extensions led to worse outcomes included: first-dose effectiveness < 65% against death; or protection following first dose waning to 0% by month three before the scheduled 2nd dose at 24-weeks. Probabilistic simulations from a range of likely vaccine effectiveness values did not result in worse outcomes with extended intervals.ConclusionUnder real-world effectiveness conditions, our results support a strategy of extending mRNA dose intervals across all age groups to minimize symptomatic cases, hospitalizations, and deaths while vaccine supply is constrained.

scholarly journals Insights Into the Effects of Mucosal Epithelial and Innate Immune Dysfunction in Older People on Host Interactions With Streptococcus pneumoniae

2021 ◽  
Vol 11 ◽  
Author(s):  
Caroline M. Weight ◽  
Simon P. Jochems ◽  
Hugh Adler ◽  
Daniela M. Ferreira ◽  
Jeremy S. Brown ◽  
...  
Keyword(s):  
Streptococcus Pneumoniae ◽  
Older People ◽  
Immune Cell ◽  
Herd Immunity ◽  
Pneumococcal Infection ◽  
Innate Immune ◽  
Older Individuals ◽  
Serotype Replacement ◽  
Pneumococcal Colonization ◽  
The Impact

In humans, nasopharyngeal carriage of Streptococcus pneumoniae is common and although primarily asymptomatic, is a pre-requisite for pneumonia and invasive pneumococcal disease (IPD). Together, these kill over 500,000 people over the age of 70 years worldwide every year. Pneumococcal conjugate vaccines have been largely successful in reducing IPD in young children and have had considerable indirect impact in protection of older people in industrialized country settings (herd immunity). However, serotype replacement continues to threaten vulnerable populations, particularly older people in whom direct vaccine efficacy is reduced. The early control of pneumococcal colonization at the mucosal surface is mediated through a complex array of epithelial and innate immune cell interactions. Older people often display a state of chronic inflammation, which is associated with an increased mortality risk and has been termed ‘Inflammageing’. In this review, we discuss the contribution of an altered microbiome, the impact of inflammageing on human epithelial and innate immunity to S. pneumoniae, and how the resulting dysregulation may affect the outcome of pneumococcal infection in older individuals. We describe the impact of the pneumococcal vaccine and highlight potential research approaches which may improve our understanding of respiratory mucosal immunity during pneumococcal colonization in older individuals.

scholarly journals Predictions of COVID-19 dynamics in the UK: Short-term forecasting and analysis of potential exit strategies

2021 ◽  
Vol 17 (1) ◽  
pp. e1008619
Author(s):  
Matt J. Keeling ◽  
Edward M. Hill ◽  
Erin E. Gorsich ◽  
Bridget Penman ◽  
Glen Guyver-Fletcher ◽  
...  
Keyword(s):  
Critical Care ◽  
Health Service ◽  
Age Groups ◽  
Transmission Model ◽  
Bed Occupancy ◽  
Time Data ◽  
Social Distancing ◽  
Number Of Patients ◽  
The Uk ◽  
The Impact

Efforts to suppress transmission of SARS-CoV-2 in the UK have seen non-pharmaceutical interventions being invoked. The most severe measures to date include all restaurants, pubs and cafes being ordered to close on 20th March, followed by a “stay at home” order on the 23rd March and the closure of all non-essential retail outlets for an indefinite period. Government agencies are presently analysing how best to develop an exit strategy from these measures and to determine how the epidemic may progress once measures are lifted. Mathematical models are currently providing short and long term forecasts regarding the future course of the COVID-19 outbreak in the UK to support evidence-based policymaking. We present a deterministic, age-structured transmission model that uses real-time data on confirmed cases requiring hospital care and mortality to provide up-to-date predictions on epidemic spread in ten regions of the UK. The model captures a range of age-dependent heterogeneities, reduced transmission from asymptomatic infections and produces a good fit to the key epidemic features over time. We simulated a suite of scenarios to assess the impact of differing approaches to relaxing social distancing measures from 7th May 2020 on the estimated number of patients requiring inpatient and critical care treatment, and deaths. With regard to future epidemic outcomes, we investigated the impact of reducing compliance, ongoing shielding of elder age groups, reapplying stringent social distancing measures using region based triggers and the role of asymptomatic transmission. We find that significant relaxation of social distancing measures from 7th May onwards can lead to a rapid resurgence of COVID-19 disease and the health system being quickly overwhelmed by a sizeable, second epidemic wave. In all considered age-shielding based strategies, we projected serious demand on critical care resources during the course of the pandemic. The reintroduction and release of strict measures on a regional basis, based on ICU bed occupancy, results in a long epidemic tail, until the second half of 2021, but ensures that the health service is protected by reintroducing social distancing measures for all individuals in a region when required. Our work confirms the effectiveness of stringent non-pharmaceutical measures in March 2020 to suppress the epidemic. It also provides strong evidence to support the need for a cautious, measured approach to relaxation of lockdown measures, to protect the most vulnerable members of society and support the health service through subduing demand on hospital beds, in particular bed occupancy in intensive care units.

THE FEATURES OF FORMATION SOMATIC PATHOLOGIES AT INFLUENCE OF LOCAL VIBRATION IN THE CONDITIONS OF METALLURGICAL MANUFACTURE

2021 ◽  
Author(s):  
E.L. Bazarova ◽  
◽  
I.S. Osherov ◽  
N.A. Roslaya ◽  
Keyword(s):  
Working Conditions ◽  
Negative Impact ◽  
Age Groups ◽  
Average Degree ◽  
Production Environment ◽  
Local Vibration ◽  
Relative Risks ◽  
Gender And Age ◽  
Age Features ◽  
The Impact

Abstract: Relevance. Local vibration is a significant factor in the production environment of metallurgical production, which affects health and efficiency. The aim of the study is to identify the exposure, gender and age features of the formation of general somatic morbidity associated with the impact of local vibration in the production of titanium alloys. Scope and methods. The prevalence of general somatic pathology was compared in 2596 workers who have contact with local vibration, with varying degrees of harmfulness of working conditions, and non-exposed persons according to the results of periodic medical examination using the methodology of occupational risk analysis of the Research Institute of Occupational Medicine. academician N. F. Izmerov. Results. At comparison of prevalence of a somatic pathology at workers in contact to local vibration to not exhibited persons according to medical inspection, and at different degree of harm of working conditions, are revealed the raised risks of formation of diseases nervous, kostno-muscular, endocrine systems, respiratory organs, digestion, an ear, a skin, an arterial hypertensia, the mental frustration, the raised weight of a body, gynecologic diseases with a tendency of growth of the majority of them at the big levels of vibration, more often at small, less often - average degree of communication with working conditions. The frequency of pathology in exposed workers was higher in all age groups. Average degree of communication with working conditions of a gynecologic pathology at the age of 18-25 years was marked. At men frequency of a pathology of respiratory organs, digestion is revealed authentically big, than at women; an ear; skin at the big relative risks 1,2-1,3, of the raised arterial pressure and hyperglycemia. Conclusion. A higher frequency of visceral pathology of a number of body systems under the influence of local vibration of high levels may justify the need to develop differentiated preventive programs to minimize its negative impact, taking into account the identified features in sex and age groups.

scholarly journals On the Role of Different Age Groups and Pertussis Vaccines During the 2012 Outbreak in Wisconsin

2018 ◽  
Vol 5 (5) ◽  
Author(s):  
Edward Goldstein ◽  
Colin J Worby ◽  
Marc Lipsitch
Keyword(s):  
Protective Effect ◽  
Age Groups ◽  
Vaccination Status ◽  
Relative Role ◽  
Age Group ◽  
Limited Information ◽  
Infection Transmission ◽  
Status Analysis ◽  
The Impact

Abstract Background There is limited information on the roles of different age groups in propagating pertussis outbreaks, and on the impact of vaccination on pertussis transmission in the community. Methods The relative roles of different age groups in propagating the 2012 pertussis outbreak in Wisconsin were evaluated using the relative risk (RR) statistic that measures the change in the group’s proportion among all detected cases before vs after the epidemic peak. The impact of vaccination in different age groups against infection (that is potentially different from the protective effect against detectable disease) was evaluated using the odds ratios (ORs), within each age group, for being vaccinated vs undervaccinated before vs after the outbreak’s peak. Results The RR statistic suggests that children aged 13–14 years played the largest relative role during the outbreak’s ascent (with estimates consistent across the 3 regions in Wisconsin that were studied), followed by children aged 7–8, 9–10, and 11–12 years. Young children and older teenagers and adults played more limited relative roles during the outbreak. Results of the vaccination status analysis for the fifth dose of DTaP (for children aged 7–8 years: OR, 0.44; 95% confidence interval [CI], 0.23–0.86; for children aged 9–10 years: OR, 0.51; 95% CI, 0.27–0.95); and for Tdap for children aged 13–14 years (OR, 0.38, 95% CI, 0.16–0.89) are consistent with protective effect against infection. Conclusions While our epidemiological findings for the fifth dose of DTaP and for Tdap are consistent with protective effect against infection, further studies, including those estimating vaccine effectiveness against infection/transmission to others particularly for pertussis vaccines for adolescents, are needed to evaluate the impact of vaccination on the spread of pertussis in the community.

Sign in / Sign up

Export Citation Format

Share Document