scholarly journals Contact surveys reveal heterogeneities in age-group contributions to SARS-CoV-2 dynamics in the United States

Author(s):  
Taylor Chin ◽  
Dennis M. Feehan ◽  
Caroline O. Buckee ◽  
Ayesha S. Mahmud

SARS-CoV-2 is spread primarily through person-to-person contacts. Quantifying population contact rates is important for understanding the impact of physical distancing policies and for modeling COVID-19, but contact patterns have changed substantially over time due to shifting policies and behaviors. There are surprisingly few empirical estimates of age-structured contact rates in the United States both before and throughout the COVID-19 pandemic that capture these changes. Here, we use data from six waves of the Berkeley Interpersonal Contact Survey (BICS), which collected detailed contact data between March 22, 2020 and February 15, 2021 across six metropolitan designated market areas (DMA) in the United States. Contact rates were low across all six DMAs at the start of the pandemic. We find steady increases in the mean and median number of contacts across these localities over time, as well as a greater proportion of respondents reporting a high number of contacts. We also find that young adults between ages 18 and 34 reported more contacts on average compared to other age groups. The 65 and older age group consistently reported low levels of contact throughout the study period. To understand the impact of these changing contact patterns, we simulate COVID-19 dynamics in each DMA using an age-structured mechanistic model. We compare results from models that use BICS contact rate estimates versus commonly used alternative contact rate sources. We find that simulations parameterized with BICS estimates give insight into time-varying changes in relative incidence by age group that are not captured in the absence of these frequently updated estimates. We also find that simulation results based on BICS estimates closely match observed data on the age distribution of cases, and changes in these distributions over time. Together these findings highlight the role of different age groups in driving and sustaining SARS-CoV-2 transmission in the U.S. We also show the utility of repeated contact surveys in revealing heterogeneities in the epidemiology of COVID-19 across localities in the United States.

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Dennis M. Feehan ◽  
Ayesha S. Mahmud

AbstractSARS-CoV-2 is transmitted primarily through close, person-to-person interactions. Physical distancing policies can control the spread of SARS-CoV-2 by reducing the amount of these interactions in a population. Here, we report results from four waves of contact surveys designed to quantify the impact of these policies during the COVID-19 pandemic in the United States. We surveyed 9,743 respondents between March 22 and September 26, 2020. We find that interpersonal contact has been dramatically reduced in the US, with an 82% (95%CI: 80%–83%) reduction in the average number of daily contacts observed during the first wave compared to pre-pandemic levels. However, we find increases in contact rates over the subsequent waves. We also find that certain demographic groups, including people under 45 and males, have significantly higher contact rates than the rest of the population. Tracking these changes can provide rapid assessments of the impact of physical distancing policies and help to identify at-risk populations.


2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Jackie Kleynhans ◽  
Stefano Tempia ◽  
Meredith L. McMorrow ◽  
Anne von Gottberg ◽  
Neil A. Martinson ◽  
...  

Abstract Background Describing contact patterns is crucial to understanding infectious disease transmission dynamics and guiding targeted transmission mitigation interventions. Data on contact patterns in Africa, especially South Africa, are limited. We measured and compared contact patterns in a rural and urban community, South Africa. We assessed participant and contact characteristics associated with differences in contact rates. Methods We conducted a cross-sectional study nested in a prospective household cohort study. We interviewed participants to collect information on persons in contact with for one day. We described self-reported contact rates as median number people contacted per day, assessed differences in contact rates based on participant characteristics using quantile regression, and used a Poisson model to assess differences in contact rates based on contact characteristics within age groups. We also calculated cumulative person hours in contact within age groups at different locations. Results We conducted 535 interviews (269 rural, 266 urban), with 17,252 contacts reported. The overall contact rate was 14 (interquartile range (IQR) 9–33) contacts per day. Those ≤18 years had higher contact rates at the rural site (coefficient 17, 95% confidence interval (95%CI) 10–23) compared to the urban site, for those aged 14–18 years (13, 95%CI 3–23) compared to < 7 years. No differences were observed for adults. There was a strong age-based mixing, with age groups interacting more with similar age groups, but also interaction of participants of all ages with adults. Children aged 14–18 years had the highest cumulative person hours in contact (116.3 rural and 76.4 urban). Conclusions Age played an important role in the number and duration of contact events, with children at the rural site having almost double the contact rate compared to the urban site. These contact rates can be utilized in mathematical models to assess transmission dynamics of infectious diseases in similar communities.


2020 ◽  
Vol 79 (Suppl 1) ◽  
pp. 156.1-156
Author(s):  
E. Yen ◽  
D. Singh ◽  
M. Wu ◽  
R. Singh

Background:Premature mortality is an important way to quantify disease burden. Patients with systemic sclerosis (SSc) can die prematurely of disease, however, the premature mortality burden of SSc is unknown. The years of potential life lost (YPLL), in addition to age-standardized mortality rate (ASMR) in younger ages, can be used as measures of premature death.Objectives:To evaluate the premature mortality burden of SSc by calculating: 1) the proportions of SSc deaths as compared to deaths from all other causes (non-SSc) by age groups over time, 2) ASMR for SSc relative to non-SSc-ASMR by age groups over time, and 3) the YPLL for SSc relative to other autoimmune diseases.Methods:This is a population-based study using a national mortality database of all United States residents from 1968 through 2015, with SSc recorded as the underlying cause of death in 46,798 deaths. First, we calculated the proportions of deaths for SSc and non-SSc by age groups for each of 48 years and performed joinpoint regression trend analysis1to estimate annual percent change (APC) and average APC (AAPC) in the proportion of deaths by age. Second, we calculated ASMR for SSc and non-SSc causes and ratio of SSc-ASMR to non-SSc-ASMR by age groups for each of 48 years, and performed joinpoint analysis to estimate APC and AAPC for these measures (SSc-ASMR, non-SSc-ASMR, and SSc-ASMR/non-SSc-ASMR ratio) by age. Third, to calculate YPLL, each decedent’s age at death from a specific disease was subtracted from an arbitrary age limit of 75 years for years 2000 to 2015. The years of life lost were then added together to yield the total YPLL for each of 13 preselected autoimmune diseases.Results:23.4% of all SSc deaths as compared to 13.5% of non-SSc deaths occurred at <45 years age in 1968 (p<0.001, Chi-square test). In this age group, the proportion of annual deaths decreased more for SSc than for non-SSc causes: from 23.4% in 1968 to 5.7% in 2015 at an AAPC of -2.2% (95% CI, -2.4% to -2.0%) for SSc, and from 13.5% to 6.9% at an AAPC of -1.5% (95% CI, -1.9% to -1.1%) for non-SSc. Thus, in 2015, the proportion of SSc and non-SSc deaths at <45 year age was no longer significantly different. Consistently, SSc-ASMR decreased from 1.0 (95% CI, 0.8 to 1.2) in 1968 to 0.4 (95% CI, 0.3 to 0.5) per million persons in 2015, a cumulative decrease of 60% at an AAPC of -1.9% (95% CI, -2.5% to -1.2%) in <45 years old. The ratio of SSc-ASMR to non-SSc-ASMR also decreased in this age group (cumulative -20%, AAPC -0.3%). In <45 years old, the YPLL for SSc was 65.2 thousand years as compared to 43.2 thousand years for rheumatoid arthritis, 18.1 thousand years for dermatomyositis,146.8 thousand years for myocarditis, and 241 thousand years for type 1 diabetes.Conclusion:Mortality at younger ages (<45 years) has decreased at a higher pace for SSc than from all other causes in the United States over a 48-year period. However, SSc accounted for more years of potential life lost than rheumatoid arthritis and dermatomyositis combined. These data warrant further studies on SSc disease burden, which can be used to develop and prioritize public health programs, assess performance of changes in treatment, identify high-risk populations, and set research priorities and funding.References:[1]Yen EY….Singh RR. Ann Int Med 2017;167:777-785.Disclosure of Interests:None declared


Neurology ◽  
2020 ◽  
Vol 95 (16) ◽  
pp. e2200-e2213 ◽  
Author(s):  
Fadar Oliver Otite ◽  
Smit Patel ◽  
Richa Sharma ◽  
Pushti Khandwala ◽  
Devashish Desai ◽  
...  

ObjectiveTo test the hypothesis that race-, age-, and sex-specific incidence of cerebral venous thrombosis (CVT) has increased in the United States over the last decade.MethodsIn this retrospective cohort study, validated ICD codes were used to identify all new cases of CVT (n = 5,567) in the State Inpatients Databases (SIDs) of New York and Florida (2006–2016). A new CVT case was defined as first hospitalization for CVT in the SID without prior CVT hospitalization. CVT counts were combined with annual Census data to compute incidence. Joinpoint regression was used to evaluate trends in incidence over time.ResultsFrom 2006 to 2016, annual age- and sex-standardized incidence of CVT in cases per 1 million population ranged from 13.9 to 20.2, but incidence varied significantly by sex (women 20.3–26.9, men 6.8–16.8) and by age/sex (women 18–44 years of age 24.0–32.6, men 18–44 years of age 5.3–12.8). Incidence also differed by race (Blacks: 18.6–27.2; Whites: 14.3–18.5; Asians: 5.1–13.8). On joinpoint regression, incidence increased across 2006 to 2016, but most of this increase was driven by an increase in all age groups of men (combined annualized percentage change [APC] 9.2%, p < 0.001), women 45 to 64 years of age (APC 7.8%, p < 0.001), and women ≥65 years of age (APC 7.4%, p < 0.001). Incidence in women 18 to 44 years of age remained unchanged over time.ConclusionCVT incidence is disproportionately higher in Blacks compared to other races. New CVT hospitalizations increased significantly over the last decade mainly in men and older women. Further studies are needed to determine whether this increase represents a true increase from changing risk factors or an artifactual increase from improved detection.


2013 ◽  
Vol 27 (3) ◽  
pp. 3-20 ◽  
Author(s):  
Facundo Alvaredo ◽  
Anthony B Atkinson ◽  
Thomas Piketty ◽  
Emmanuel Saez

The top 1 percent income share has more than doubled in the United States over the last 30 years, drawing much public attention in recent years. While other English-speaking countries have also experienced sharp increases in the top 1 percent income share, many high-income countries such as Japan, France, or Germany have seen much less increase in top income shares. Hence, the explanation cannot rely solely on forces common to advanced countries, such as the impact of new technologies and globalization on the supply and demand for skills. Moreover, the explanations have to accommodate the falls in top income shares earlier in the twentieth century experienced in virtually all high-income countries. We highlight four main factors. The first is the impact of tax policy, which has varied over time and differs across countries. Top tax rates have moved in the opposite direction from top income shares. The effects of top rate cuts can operate in conjunction with other mechanisms. The second factor is a richer view of the labor market, where we contrast the standard supply-side model with one where pay is determined by bargaining and the reactions to top rate cuts may lead simply to a redistribution of surplus. Indeed, top rate cuts may lead managerial energies to be diverted to increasing their remuneration at the expense of enterprise growth and employment. The third factor is capital income. Overall, private wealth (relative to income) has followed a U-shaped path over time, particularly in Europe, where inherited wealth is, in Europe if not in the United States, making a return. The fourth, little investigated, element is the correlation between earned income and capital income, which has substantially increased in recent decades in the United States.


Author(s):  
Christina M Ackerman ◽  
Jennifer L Nguyen ◽  
Swapna Ambati ◽  
Maya Reimbaeva ◽  
Birol Emir ◽  
...  

Abstract Background Pregnant women with coronavirus disease 19 (COVID-19) may be at greater risk of poor maternal and pregnancy outcomes. This retrospective analysis reports clinical and pregnancy outcomes among hospitalized pregnant women with COVID-19 in the United States. Methods The Premier Healthcare Database – Special Release was used to examine the impact of COVID-19 among pregnant women aged 15–44 years who were hospitalized and who delivered compared with pregnant women without COVID-19. Outcomes evaluated were COVID-19 clinical progression, including the use of supplemental oxygen therapy, intensive care unit admission, critical illness, receipt of invasive mechanical ventilation/extracorporeal membrane oxygenation, and maternal death, and pregnancy outcomes, including preterm delivery and stillbirth. Results Overall, 473,902 hospitalized pregnant women were included, of whom 8584 (1.8%) had a COVID-19 diagnosis (mean [SD] age 28.4 [6.1] years; 40% Hispanic). The risk of poor clinical and pregnancy outcomes was greater among pregnant women with COVID-19 compared with pregnant women without a COVID-19 diagnosis in 2020; the risk of poor clinical and pregnancy outcomes increased with increasing age. Hispanic and Black non-Hispanic women were consistently observed to have the highest relative risk of experiencing poor clinical or pregnancy outcomes across all age groups. Conclusions Overall, COVID-19 had a significant negative impact on maternal health and pregnancy outcomes. These data help inform clinical practice and counselling to pregnant women regarding the risks of COVID-19. Clinical studies evaluating the safety and efficacy of vaccines against severe acute respiratory syndrome coronavirus 2 in pregnant women are urgently needed.


Author(s):  
Brittny C Davis Lynn ◽  
Pavel Chernyavskiy ◽  
Gretchen L Gierach ◽  
Philip S Rosenberg

Abstract Background Incidence of estrogen receptor (ER)-negative breast cancer, an aggressive subtype, is highest in United States (US) African American women and in southern residents but has decreased overall since 1992. We assessed whether ER-negative breast cancer is decreasing in all age groups and cancer registries among non-Hispanic White (NHW), non-Hispanic Black (NHB), and Hispanic White (HW) women. Methods We analyzed 17 Surveillance, Epidemiology, and End-Results Program registries (twelve for 1992-2016; five for 2000-2016) to assess NHW, NHB, and HW trends by ER status and age group (30-39, 40-49, 50-69, 70-84 years). We used hierarchical age-period-cohort models that account for sparse data, which improve estimates to quantify between-registry heterogeneity in mean incidence rates and age-adjusted trends versus SEER overall. Results Overall, ER-negative incidence was highest in NHB, then NHW and HW women, and decreased from 1992-2016 in each age group and racial/ethnic group. The greatest decrease was for HW women ages 40-49 years with an annual percent change of –3.5%/year (95% credible interval = −4.4%, −2.7%), averaged over registries. The trend heterogeneity was statistically significant in every race/ethnic and age group. Furthermore, the incidence relative risks by race/ethnicity compared to the race-specific SEER average were also statistically significantly heterogeneous across the majority of registries and age groups (62 of 68 strata). The greatest heterogeneity was seen in HW women, followed by NHB women, and the least in NHW women. Conclusion Decreasing ER-negative breast cancer incidence differs meaningfully by US region and age among NHB and HW women. Analytical studies including minority women from higher and lower incidence areas may provide insights into breast cancer racial disparities.


Stroke ◽  
2020 ◽  
Vol 51 (Suppl_1) ◽  
Author(s):  
Sai P Polineni ◽  
Fadar O Otite ◽  
Seemant Chaturvedi

Background: The aim of this study is to evaluate current trends in racial, age, and sex-specific utilization of decompressive hemicraniectomy (HC) in acute ischemic stroke (AIS) patients in the United States over the last decade. Methods: All adult patients with a diagnosis of AIS were identified from the 2004-2015 Nationwide Inpatient Sample (weighted N=4,792,428) using International Classification of Diseases Ninth revision (ICD-9) codes. Proportion of patients undergoing HC in various age, race, and sex groups were ascertained using ICD-9 procedural codes. Temporal trends were mapped by year in order to track changes in utilization over time. Analysis of utilization disparities and trends within age, sex, and race subgroups was conducted via multivariate logistic regression. Results: Of all eligible AIS patients from 2004-2015, 0.25% underwent HC (.08 in 2004 to .46 in 2015). Increased utilization over time was seen in both men (.13 to .57) and women (.08 to .54), with women showing comparable odds of utilization to men [OR: 0.95 (95% CI: .87-1.04, p=0.27)]. Similarly, increased utilization trends were seen in all age groups (Figure 1) with the highest rates in the 18-39 subgroup (1.41%). Compared to trends in this younger subgroup (.43 to 2.12), patients aged 60-79 experienced a similar overall increase but at lower utilization rates (.06 to .37). Compared to white patients in multivariate models, blacks did not show significant differences in odds of HC [1.09 (.96-1.24, p=0.20)], while patients from Hispanic [1.25 (1.03-1.51, p=0.02)] and other [1.26 (1.04-1.52, p=0.02)] race-ethnic groups showed increased odds. Conclusions: From 2004-2015, hemicraniectomy rates have seen substantial increases in all age, sex, and race groups. The increasing rates of hemicraniectomies among those over age 60 suggest that there has been at least partial acceptance of DESTINY 2 study results.


2006 ◽  
Vol 46 (3) ◽  
pp. 382-408 ◽  
Author(s):  
Amy von Heyking

History, civics, and social studies courses in Canadian schools have always represented some official understanding of Canadian citizenship, even Canadian identity. They have prepared children for citizenship and the exercise of their adult duties in the community. As historian Ken Osborne argues, citizenship remains a “flexibly protean” term, changing over time according to setting, and always resisted or undermined by those who disagree with the official understanding imposed upon them. While it may be difficult to assess the impact of the school's messages on students, we can identify the official ideas about English-Canadian citizenship and identity transmitted by schools.


1983 ◽  
Vol 35 (3) ◽  
pp. 368-392 ◽  
Author(s):  
James N. Rosenau ◽  
Ole R. Holsti

The adaptation of the United States to its declining role as a superpower is examined through an inquiry into the belief systems of the society's leaders. Three sets of mutually exclusive domestic policy belief systems are identified, along with three sets of mutually exclusive foreign policy belief systems. The degree to which they are linked to each other is explored, and the connections are found to be tenuous—suggesting that the cleavages at work in American society are more enduring and less subject to change than may be readily apparent. The last section of the paper uses more recent data from a sample of American leaders to examine the degree to which foreign policy belief systems are susceptible to change over time, allowing for an analysis of the extent to which the hostage crisis in Iran and the Soviet invasion of Afghanistan affected pre-existing belief systems. The overall finding is that the impact was negligible, and that foreign policy belief systems are largely resistant to change.


Sign in / Sign up

Export Citation Format

Share Document