Effects of Lockdowns And Its Impacts On Age-Specific Transmission Dynamics of SARS-Cov-2 In Georgia, USA

Abstract Social distancing measures are effective in reducing overall community transmission but much remains unknown about how they have impacted finer-scale dynamics. In particular, much is unknown about how changes of contact patterns and other behaviors including adherence to social distancing, induced by these measures, may have impacted finer-scale transmission dynamics among different age groups. In this paper, we build a stochastic age-specific transmission model to systematically characterize the degree and variation of age-specific transmission dynamics, before and after lifting the lockdown in Georgia, USA. We perform Bayesian (missing-) data-augmentation model inference, leveraging reported age-specific case, seroprevalence and mortality data. We estimate that community-level transmissibility was reduced to 41.2% with 95% CI [39%, 43.8%] of the pre-lockdown level in about a week of the announcement of the shelter-in-place order. Although it subsequently increased after the lockdown was lifted, it only bounced back to 62% [58%, 67.2%] of the pre-lockdown level after about a month. We also find that during the lockdown susceptibility to infection increases with age. Specifically, relative to the oldest age group (>65+), susceptibility for the youngest age group (0-17 years) is 0.13 [0.09, 0.18], and it increases to 0.53 [0.49, 0.59] for 18-44 and 0.75 [0.68, 0.82] for 45- 64. More importantly, our results reveal clear changes of age-specific susceptibility (defined as average risk of getting infected during an infectious contact incorporating age-dependent behavioral factors) after the lockdown was lifted, with a trend largely consistent with reported age-specific adherence levels to social distancing and preventive measures. Specifically, the older groups (>45) (with the highest levels of adherence) appear to have the most significant reductions of susceptibility (e.g., post-lockdown susceptibility reduced to 31.6% [29.3%, 34%] of the estimate before lifting the lockdown for the 65+ group). Finally, we find heterogeneity in case reporting rates among different age groups, with the lowest rate occurring among the 0-18 group (9.7% [6.4%, 19%]). Our results provide a more fundamental understanding of the impacts of stringent lockdown measures, and finer evidence that other social distancing and preventive measures may be effective in reducing SARS-CoV-2 transmission. These results may be exploited to guide more effective implementations of these measures in many current settings (with low vaccination rate globally and emerging variants) and in future potential outbreaks of novel pathogens.

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SARS-CoV-2 transmission across age groups in France and implications for control

Nature Communications ◽

10.1038/s41467-021-27163-1 ◽

2021 ◽

Vol 12 (1) ◽

Author(s):

Cécile Tran Kiem ◽

Paolo Bosetti ◽

Juliette Paireau ◽

Pascal Crépey ◽

Henrik Salje ◽

...

Keyword(s):

Young Adults ◽

Age Groups ◽

Deep Understanding ◽

Transmission Dynamics ◽

Age Group ◽

Older Individuals ◽

Targeted Intervention ◽

Social Distancing ◽

Intervention Measures ◽

Better Than

AbstractThe shielding of older individuals has been proposed to limit COVID-19 hospitalizations while relaxing general social distancing in the absence of vaccines. Evaluating such approaches requires a deep understanding of transmission dynamics across ages. Here, we use detailed age-specific case and hospitalization data to model the rebound in the French epidemic in summer 2020, characterize age-specific transmission dynamics and critically evaluate different age-targeted intervention measures in the absence of vaccines. We find that while the rebound started in young adults, it reached individuals aged ≥80 y.o. after 4 weeks, despite substantial contact reductions, indicating substantial transmission flows across ages. We derive the contribution of each age group to transmission. While shielding older individuals reduces mortality, it is insufficient to allow major relaxations of social distancing. When the epidemic remains manageable (R close to 1), targeting those most contributing to transmission is better than shielding at-risk individuals. Pandemic control requires an effort from all age groups.

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Age groups that sustain resurging COVID-19 epidemics in the United States

10.1101/2020.09.18.20197376 ◽

2020 ◽

Cited By ~ 2

Author(s):

Mélodie Monod ◽

Alexandra Blenkinsop ◽

Xiaoyue Xi ◽

Daniel Hebert ◽

Sivan Bershan ◽

...

Keyword(s):

United States ◽

Elementary Schools ◽

Age Groups ◽

The United States ◽

Transmission Dynamics ◽

Transmission Model ◽

Mortality Data ◽

Contact Patterns ◽

Specific Contact ◽

Novel Coronavirus

Following initial declines, in mid 2020, a resurgence in transmission of novel coronavirus disease (COVID-19) has occurred in the United States and parts of Europe. Despite the wide implementation of non-pharmaceutical interventions, it is still not known how they are impacted by changing contact patterns, age and other demographics. As COVID-19 disease control becomes more localised, understanding the age demographics driving transmission and how these impacts the loosening of interventions such as school reopening is crucial. Considering dynamics for the United States, we analyse aggregated, age-specific mobility trends from more than 10 million individuals and link these mechanistically to age-specific COVID-19 mortality data. In contrast to previous approaches, we link mobility to mortality via age-specific contact patterns and use this rich relationship to reconstruct accurate transmission dynamics. Contrary to anecdotal evidence, we find little support for age-shifts in contact and transmission dynamics over time. We estimate that, until August, 63.4% [60.9%-65.5%] of SARS-CoV-2 infections in the United States originated from adults aged 20-49, while 1.2% [0.8%-1.8%] originated from children aged 0- 9. In areas with continued, community-wide transmission, our transmission model predicts that re-opening kindergartens and elementary schools could facilitate spread and lead to additional COVID-19 attributable deaths over a 90-day period. These findings indicate that targeting interventions to adults aged 20-49 are an important consideration in halting resurgent epidemics and preventing COVID-19-attributable deaths when kindergartens and elementary schools reopen.

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Trends of Stomach Cancer in Central Serbia

Medicina ◽

10.3390/medicina57070665 ◽

2021 ◽

Vol 57 (7) ◽

pp. 665

Author(s):

Miodrag M. Stojanovic ◽

Natasa K. Rancic ◽

Marija R. Andjelkovic Apostolovic ◽

Aleksandra M. Ignjatovic ◽

Mirko V. Ilic

Keyword(s):

Stomach Cancer ◽

Preventive Measures ◽

Age Groups ◽

Optimal Number ◽

P Value ◽

Age Group ◽

Joinpoint Regression ◽

Mortality Trends ◽

Incidence Trend ◽

Incidence And Mortality

Somach cancer is the third most common cause of cancer-related deaths worldwide. The objective of the paper was to analyze the incidence and mortality trends of stomach cancer in Central Serbia in the period between 1999–2017. Materials and Methods: trends and annual percentage change (APC) of the incidence and mortality rate with corresponding 95% confidence intervals (CI) were calculated by joinpoint regression analyses. The optimal number of Joinpoints was identified using the Monte Carlo permutation method. The trend was considered to be significantly increasing (positive change) or decreasing (negative change) when the p-value was below 0.05 (p < 0.05). Results: the total number of new cases was 16,914 (10,873 males and 6041 females) and the total number of mortality cases was 14,790 (9348 in and 5442 in females). Almost one third (30.8%) of new cases were registered in the 60–69-year age group, and new cases were significantly more frequent in males than in females (30.8% vs. 29.02%, p < 0.001). Joinpoint regression analysis showed a significant decrease of incidence trend in females during the 2000–2015 period with APC of −2.13% (95% CI: −3.8 to −0.5, p < 0.001). An insignificant decrease in incidence trend was in males with APC of −0.72% (95% CI: −2.3 to 0.9, p = 0.30). According to the joinpoint analysis, a significant decrease of mortality trends both in males during 2000–2015 with APC of −2.21% (95% CI: −1.6 to −7.5, p ≤ 0.001 and in females, during the same period, with APC of −1.75% (95% CI: −2.9 to −0.6, p < 0.001) was registered. From 2015 to 2017, a significant increase of mortality was registered with APC of 44.5% (95% CI: from 24.2 to −68.1, p ≤ 0.001) in females and in males with APC of 53.15% (95% CI: 13.5 to −106.6, p ≤ 0.001). Conclusion: a significant decrease of stomach cancer incidence trend in females and insignificant decrease of incidence trend in males were determined in Central Serbia. Based on presented results, the mortality trend decreased significantly both in males and in females during 2000–2015, and from 2015 to 2017 we recorded a significant increase in mortality in both sexes. We found significantly more new cases in women than in men in the age group of 40–49, and the mortality of stomach cancer was significantly more frequent among females compared to males in the age groups 30–39, as well as in the 50–59 age group. There is a need for improving recording and registration of new cases of stomach cancer, especially in females. Urgent primary and secondary preventive measures are needed—introducing stomach cancer screening and early detection of premalignant changes. Urgent primary and secondary preventive measures are needed.

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Oral Health of Individuals with Cleft Lip, Cleft Palate, or Both

The Cleft Palate-Craniofacial Journal ◽

10.1597/02-058 ◽

2004 ◽

Vol 41 (1) ◽

pp. 59-63 ◽

Cited By ~ 26

Author(s):

Elizabeth Maria Bastos Lages ◽

Badeia Marcos ◽

Isabela Almeida Pordeus

Keyword(s):

Oral Health ◽

General Population ◽

Cleft Lip ◽

Cleft Lip And Palate ◽

Preventive Measures ◽

Age Groups ◽

Gingival Recession ◽

Age Group ◽

Visual Examination ◽

Probing Depth

Objective To evaluate the oral health of children with cleft lip and palate. Design DMFT (dmft) and DMFS (dmfs) were calculated on the basis of visual examination. Periodontal disease was assessed by classical clinical parameters: volume gain, bleeding, probing depth, loss of insertion, gingival recession. and calculus. Patients Seventy-eight individuals aged 1 to 32 years took part in the study. Results The dmft was 2.91 (± 3.99) in the 1- to 5-year-old age group and 2.77 (± 3.15) in the 6- to 12-year-old group. The DMFT averages for the age groups of 6 to 12 years, 13 to 18 years, and 19 to 32 years were 1.87 (± 1.78), 6.46 (± 3.11), and 13.62 (± 6.51), respectively. A total of 5.3% of individuals presented a healthy periodontium, and 86.6% presented with gingivitis and 8% presented with periodontitis. Conclusions The dental and periodontal condition of individuals with cleft lip and palate was similar to the general population in the region in which this study was conducted. Good preventive measures should result in improved oral health similar to the general population and should be emphasized.

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SEASONAL AGE DYNAMICS OF EIMERIOSIS AND CRYPTOSPORIDI-OSIS OF CATTLE

International bulletin of Veterinary Medicine ◽

10.17238/issn2072-2419.2020.3.24 ◽

2020 ◽

Vol 3 ◽

pp. 24-29

Author(s):

E.S. Klimova ◽

◽

M.E. Mkrtchyan ◽

E.V. Maksimova ◽

A.D. Reshetnikova ◽

...

Keyword(s):

Seasonal Dynamics ◽

Preventive Measures ◽

Age Groups ◽

Central Zone ◽

Age Group ◽

Age Dynamics ◽

Research Material ◽

Age Related ◽

Udmurt Republic

Currently, the topic of determination of the seasonal and age-related dynamics of eimeria and cryptosporidia, especially with their associative course in cattle on farms of the Udmurt Republic, remains relevant. The research material were represented by fecal samples (1629 samples) from animals of various age groups of the central zone of Udmurtia, spontaneously infected with eime-ria and cryptosporidia. Coprological studies were performed monthly by generally accepted flotation methods, and fingerprint smears were made, followed by Ziehl-Nielsen staining. Our studies on the seasonal dynamics of protozoa showed that peaks of infection in animals in the central zone of the Udmurt Republic were noted in the autumn-winter periode. The age dynamics in the regions differed significantly depending on the type of pathogen and the age of the animals. Thus, Zavyalovsky is a stationary dysfunctional area for eimeriosis and cryptosporidiosis, where the per-centage of eimeriosis infection is 96.3%. At the same time, the maximum number of ocists were observed in young animals in age of 8-12 months. Cryptosporidiosis infestation was recorded from 3 days of age to 2 months, and the percentage of infection in this age group reached 89,66%.The results of our studies revealed a fairly widespread association of these protozooses. So, it was found that in Zavyalovsky district, the maximum intensi-ty of mixtinvasion is recorded in animals aged 1-2 months and reaches up to 69,17%. In the Uvinsky district, the greatest degree of infection with the association of eimeria and cryptosporidia is record-ed almost 2 times less often (in 37,31% of cas-es).The results of seasonal dynamics must be taken into account for drawing up treatment and preventive measures for various age groups of animals in the central zone of the Udmurt Republic.

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

PLoS Computational Biology ◽

10.1371/journal.pcbi.1008619 ◽

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.

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Vaccination Prioritization Strategies for COVID-19 in Korea: A Mathematical Modeling Approach

International Journal of Environmental Research and Public Health ◽

10.3390/ijerph18084240 ◽

2021 ◽

Vol 18 (8) ◽

pp. 4240

Author(s):

Yongin Choi ◽

James Slghee Kim ◽

Jung Eun Kim ◽

Heejin Choi ◽

Chang Hyeong Lee

Keyword(s):

Age Groups ◽

Epidemiological Data ◽

The Elderly ◽

Age Group ◽

Elderly Age ◽

Social Distancing ◽

Vaccination Strategies ◽

Effective Age ◽

Incidence And Mortality ◽

Age Dependent

Coronavirus disease 2019 (COVID-19) vaccination has recently started worldwide. As the vaccine supply will be limited for a considerable period of time in many countries, it is important to devise the effective vaccination strategies that reduce the number of deaths and incidence of infection. One of the characteristics of COVID-19 is that the symptom, severity, and mortality of the disease differ by age. Thus, when the vaccination supply is limited, age-dependent vaccination priority strategy should be implemented to minimize the incidences and mortalities. In this study, we developed an age-structured model for describing the transmission dynamics of COVID-19, including vaccination. Using the model and actual epidemiological data in Korea, we estimated the infection probability for each age group under different levels of social distancing implemented in Korea and investigated the effective age-dependent vaccination strategies to reduce the confirmed cases and fatalities of COVID-19. We found that, in a lower level of social distancing, vaccination priority for the age groups with the highest transmission rates will reduce the incidence mostly, but, in higher levels of social distancing, prioritizing vaccination for the elderly age group reduces the infection incidences more effectively. To reduce mortalities, vaccination priority for the elderly age group is the best strategy in all scenarios of levels of social distancing. Furthermore, we investigated the effect of vaccine supply and efficacy on the reduction in incidence and mortality.

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Comparative Analysis of Mortality from Infectious Diseases in the Russian Federation and Some European Countries

Epidemiology and Vaccinal Prevention ◽

10.31631/2073-3046-2017-16-3-4-10 ◽

2017 ◽

Vol 16 (3) ◽

pp. 4-10 ◽

Cited By ~ 5

Author(s):

R. V. Polibin ◽

A. Ya. Mindlina ◽

A. A. Gerasimov ◽

N. I. Briko

Keyword(s):

Infectious Diseases ◽

Russian Federation ◽

Preventive Measures ◽

Clinical Epidemiology ◽

Age Groups ◽

Care Quality ◽

European Countries ◽

Mortality Data ◽

Working Age ◽

The Russian Federation

The purpose. To conduct comparative evaluation of mortality from infectious diseases and medical care quality in Russia and some European countries in different age groups. Materials and methods. Selection of mortality data was performed from various Russian and foreign databases. Ranking of countries according to mortality rates was done with a quartiles calculation method. For evaluating the adherence to preventive measures surveys of different population groups, to assess adherence to the principles of clinical epidemiology and evidence-based medicine was conducted a continuous survey of doctors, one branch of the municipal polyclinic of Moscow. The results and discussion. It is shown that the situation in the Russian Federation as a whole can be assessed as disadvantaged in mortality from infectious diseases in all age groups. Conclusions. A reduction in mortality among children as well as working-age population requires a comprehensive approach that should include both of improvement of quality of care and the formation of commitment to preventive measures.

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Age-Structured Model for COVID-19: Effectiveness of Social Distancing and Contact Reduction

10.21203/rs.3.rs-33480/v1 ◽

2020 ◽

Author(s):

Mark Kimathi ◽

Samuel Mwalili ◽

Viona Ojiambo ◽

Duncan Gathungu

Keyword(s):

Deterministic Model ◽

Age Groups ◽

School Closure ◽

Model Parameters ◽

Suitable Model ◽

Age Group ◽

Social Distancing ◽

First Case ◽

Age Structured ◽

The Impact

Abstract Background: Coronavirus disease 2019 is caused by severe acute respiratory syndrome coronavirus 2. The disease has spread to almost every country in the world. Kenya reported its first case on 13th of March 2020. From 16th March 2020, the country instituted various social distancing strategies to reduce the transmission and flatten the epidemic curve. These strategies include school closure, dusk-to-dawn curfew, and travel restriction across counties, especially Nairobi, Mombasa and Kwale. An age-structured compartmental model was developed to assess the impact of non-pharmaceutical interventions on severity of infections, hospital demands and deaths. Methods: The population is divided into four age-groups and for each age-group there are seven compartments, namely: susceptible , exposed, asymptomatic, mild, severe, critical, death and recovered. The contact matrices between the different ages are integrated into an age-structured deterministic model via the force of infection. This model is represented by ordinary differential equations and solved using Runge–Kutta methods, with suitable model parameters. Simulation results for the unmitigated and mitigated scenarios were depicted, for the different age-groups. Results: The 45% reduction in contacts for 60-days period resulted to between 11.5-13% reduction of infections severity and deaths, while for the 190-days period yielded between 18.8-22.7% reduction. The peak of infections in the 60-days mitigation was higher and happened about 2 months after the relaxation of mitigation as compared to that of the 190-days mitigation, which happened just a month after mitigation were relaxed. Low numbers of cases in children under 15 years was attributed to low susceptibility of persons in this age-group. High numbers of cases are reported in the 15-29 years and 30-59 years age bands since these individuals have wider interaction spheres, and they form a significant percentage of Kenya population. Conclusion: Two mitigation periods, considered in the study, resulted to reductions in severe and critical cases, attack rates, hospital and ICU bed demands, as well as deaths, with the 190-days period giving higher reductions. The study revealed the age-dependency of the key health outputs.

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The Prevalence of Risk Factors of Breast Cancer in Different Age Groups of the Female Population of the Omsk Region

Epidemiology and Vaccinal Prevention ◽

10.31631/2073-3046-2017-16-6-40-46 ◽

2017 ◽

Vol 16 (6) ◽

pp. 40-46

Author(s):

N. G. Shirlina ◽

V. L. Stasenko ◽

V. A. Shirinskiy ◽

T. M. Obukhova

Keyword(s):

Breast Cancer ◽

Risk Factors ◽

Integrated Assessment ◽

Preventive Measures ◽

Age Groups ◽

Specific Weight ◽

Age Group ◽

Female Population ◽

The Third ◽

Different Ages

The paper estimates the prevalence of the main risk factors for breast cancer (BC) in different age groups of the female population of the Omsk Region. Priority groups for the correction of risk factors in five age intervals were identified. According to the results of an integrated assessment of the aggregate of risk factors at different ages of women, the age group 60-69 years old was in the first ranking place for the priority of preventive measures, the second group was 70 years or more, the third group included a group of 30-39 year old women. The specific weight of the corrected risk factors in this group of respondents was 85.7%, which determines the potential of preventive measures.

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