The Role of Environmental Transmission in Recurrent Avian Influenza Epidemics

Avian influenza virus (AIV) persists in North American wild waterfowl, exhibiting major outbreaks every 2–4 years. Attempts to explain the patterns of periodicity and persistence using simple direct transmission models are unsuccessful. Motivated by empirical evidence, we examine the contribution of an overlooked AIV transmission mode: environmental transmission. It is known that infectious birds shed large concentrations of virions in the environment, where virions may persist for a long time. We thus propose that, in addition to direct fecal/oral transmission, birds may become infected by ingesting virions that have long persisted in the environment. We design a new host–pathogen model that combines within-season transmission dynamics, between-season migration and reproduction, and environmental variation. Analysis of the model yields three major results. First, environmental transmission provides a persistence mechanism within small communities where epidemics cannot be sustained by direct transmission only (i.e., communities smaller than the critical community size). Second, environmental transmission offers a parsimonious explanation of the 2–4 year periodicity of avian influenza epidemics. Third, very low levels of environmental transmission (i.e., few cases per year) are sufficient for avian influenza to persist in populations where it would otherwise vanish

Health Behaviors of Breast Cancer Survivors with Hypertension: A Propensity Analysis of KNHANES III-V (2005-2012).

This study examines health behaviors of breast cancer survivors with hypertension and compares them with those of non-cancer individuals with hypertension.In this cross-sectional study, a total of 10,996 hypertensive adults (≥ 19 years) who participated in the 2005-2012 Korean National Health and Nutrition Examination Survey (KNHANES) were considered. Data on alcohol consumption, smoking, physical activity, antihypertensive medication adherence, self-reported diet control, and sodium intake were collected through self-report questionnaire. A total of 64 breast cancer survivors with hypertension and 10,932 non-cancer participants with hypertension were identified. To better compare health behaviors of the two groups, 56 breast cancer survivors and 280 non-cancer participants were selected through the 1:5 nearest available matching based on estimated propensity scores. Multivariate analysis was conducted to determine any differences between the two groups.According to multivariate analysis, breast cancer survivors with hypertension (n = 56) were significantly less likely to consume alcohol (odds ratio (OR): 3.75; 95% confidence interval (CI): 1.06-13.29) but significantly more likely to have sodium intake of more than 2400 mg (OR: 2.98; 95% CI: 1.27-6.97) than the propensity-matched control group (n = 280). There was no significant difference in other health behaviors between the two groups.Breast cancer survivors require active interventions for healthy behaviors related to the management of comorbid conditions such as hypertension to reduce the risk of cardiovascular disease and improve their overall survival rate

Health Behaviors of Breast Cancer Survivors with Hypertension: A Propensity Analysis of KNHANES III-V (2005-2012)

<div><p>Objective</p><p>This study examines health behaviors of breast cancer survivors with hypertension and compares them with those of non-cancer individuals with hypertension.</p><p>Methods</p><p>In this cross-sectional study, a total of 10,996 hypertensive adults (≥ 19 years) who participated in the 2005-2012 Korean National Health and Nutrition Examination Survey (KNHANES) were considered. Data on alcohol consumption, smoking, physical activity, antihypertensive medication adherence, self-reported diet control, and sodium intake were collected through self-report questionnaire. A total of 64 breast cancer survivors with hypertension and 10,932 non-cancer participants with hypertension were identified. To better compare health behaviors of the two groups, 56 breast cancer survivors and 280 non-cancer participants were selected through the 1:5 nearest available matching based on estimated propensity scores. Multivariate analysis was conducted to determine any differences between the two groups.</p><p>Results</p><p>According to multivariate analysis, breast cancer survivors with hypertension (n = 56) were significantly less likely to consume alcohol (odds ratio (OR): 3.75; 95% confidence interval (CI): 1.06-13.29) but significantly more likely to have sodium intake of more than 2400 mg (OR: 2.98; 95% CI: 1.27-6.97) than the propensity-matched control group (n = 280). There was no significant difference in other health behaviors between the two groups.</p><p>Conclusions</p><p>Breast cancer survivors require active interventions for healthy behaviors related to the management of comorbid conditions such as hypertension to reduce the risk of cardiovascular disease and improve their overall survival rate.</p></div

Sociodemographic characteristics and comorbid conditions of study participants by their cancer history before and after 1: 5 propensity score matching (KNHANES III-V, 2005–2012).

<p>Results were expressed as un-weighted numbers (weighted %) or mean ± SE (standard error).</p><p>*COPD: Chronic obstructive pulmonary disease</p><p>Sociodemographic characteristics and comorbid conditions of study participants by their cancer history before and after 1: 5 propensity score matching (KNHANES III-V, 2005–2012).</p

A comparison of health behaviors between breast cancer survivors and propensity-matched participants (KNHANES III-V, 2005–2012).

<p>Results were expressed as un-weighted numbers (weighted %)</p><p>Logistic regression models incorporated sampling weights.</p><p>¹ Unadjusted;</p><p>² Adjusted for age, height, weight, ischemic heart disease, arthritis and significant covariates (<i>p</i> ≤ 0.1) from the univariate analysis.</p><p>OR: Odds ratio; 95% CI: 95% confidence interval</p><p>A comparison of health behaviors between breast cancer survivors and propensity-matched participants (KNHANES III-V, 2005–2012).</p