Continental-scale dynamics of avian influenza in U.S. waterfowl are driven by demography, migration and temperature

Emerging diseases of wildlife origin are increasingly spilling over into humans and domestic animals. Surveillance and risk assessments for transmission between these populations are informed by a mechanistic understanding of the pathogens in wildlife reservoirs. For avian influenza viruses (AIV), much observational and experimental work in wildlife has been conducted at local scales, yet fully understanding their spread and distribution requires assessing the mechanisms acting at both local, (e.g., intrinsic epidemic dynamics), and continental scales, (e.g., long‐distance migration). Here, we combined a large, continental‐scale dataset on low pathogenic, Type A AIV in the United States with a novel network‐based application of bird banding/recovery data to investigate the migration‐based drivers of AIV and their relative importance compared to well‐characterised local drivers (e.g. demography, environmental persistence). We compared among regression models reflecting hypothesized ecological processes and evaluated their ability to predict AIV in space and time using within and out‐of‐sample validation. We found that predictors of AIV were associated with multiple mechanisms at local and continental scales. Hypotheses characterising local epidemic dynamics were strongly supported, with age, the age‐specific aggregation of migratory birds in an area and temperature being the best predictors of infection. Hypotheses defining larger, network‐based features of the migration processes, such as clustering or between‐cluster mixing explained less variation but were also supported. Therefore, our results support a role for local processes in driving the continental distribution of AIV

Avian Influenza in Wild Birds: Environmental Sampling for the Rapid Detection of Avian Influenza Viruses

All subtypes of influenza Type A viruses infect wild birds, especially waterfowl and shorebirds, but rarely cause disease or mortality in these aquatic species. Aquatic birds are the natural reservoirs for low pathogenic avian influenza viruses (LPAI) that are distributed globally. However, some AI subtypes can be virulent in other animals and humans and some highly pathogenic AI viruses (HPAI) have caused major outbreaks in poultry and even pandemics in the human population. The emergence of a HPAl H5N1 subtype in southeast Asian poultry in 1997 subsequently involved migratory waterfowl in 2005 and has since spread westward throughout the Asian, European, and African continents. This rapid continental spread planned animal and human health agencies in North America and initiated the establishment of a National Strategy for Pandemic influenza in the United States to increase and expand surveillance for the early detection of this virus, to improve and expand preventative measures, and to develop contingency responses to possible outbreaks. One of the methods of emergency surveillance developed and implemented was an interagency, early detection system for HPAI H5N1 avian influenza in wild migratory birds with the potential to bring in the virus from Asia or Europe and spread it throughout North America. As part of this early detection system, the Wildlife Services National Wildlife Research Center developed testing methods, sampling protocols, guidelines, and analyzed 50,184 avian fecal samples collected by Wildlife Service biologists in 50 states and the U. S. territories. Samples were pooled in the laboratory (n = 10,541 pools) and analyzed using RT-PCR. AI viruses were detected in 4.0% of the 10,541 sample pools analyzed and H5/H7 subtypes were detected in 0.2% of the sample pools. Positive H5 and H7 subtypes were shipped to the National Veterinary Services Laboratory for further evaluation and confirmation. This monitoring effort was successful in detecting AI viruses in environmental samples and has proven to be a rapid and cost effective surveillance method

Environmental and Demographic Determinants of Avian Influenza Viruses in Waterfowl across the Contiguous United States

Outbreaks of avian influenza in North American poultry have been linked to wild waterfowl. A first step towards understanding where and when avian influenza viruses might emerge from North American waterfowl is to identify environmental and demographic determinants of infection in their populations. Laboratory studies indicate water temperature as one determinant of environmental viral persistence and we explored this hypothesis at the landscape scale. We also hypothesized that the interval apparent prevalence in ducks within a local watershed during the overwintering season would influence infection probabilities during the following breeding season within the same local watershed. Using avian influenza virus surveillance data collected from 19,965 wild waterfowl across the contiguous United States between October 2006 and September 2009 We fit Logistic regression models relating the infection status of individual birds sampled on their breeding grounds to demographic characteristics, temperature, and interval apparent prevalence during the preceding overwintering season at the local watershed scale. We found strong support for sex, age, and species differences in the probability an individual duck tested positive for avian influenza virus. In addition, we found that for every seven days the local minimum temperature fell below zero, the chance an individual would test positive for avian influenza virus increased by 5.9 percent. We also found a twelve percent increase in the chance an individual would test positive during the breeding season for every ten percent increase in the interval apparent prevalence during the prior overwintering season. These results suggest that viral deposition in water and sub-freezing temperatures during the overwintering season may act as determinants of individual level infection risk during the subsequent breeding season. Our findings have implications for future surveillance activities in waterfowl and domestic poultry populations. Further study is needed to identify how these drivers might interact with other host-specific infection determinants, such as species phylogeny, immunological status, and behavioral characteristics

The Panama canal. A fallacy exposed. Gold is not needed.

The Panama canal

PTSD Symptom Severities, Interpersonal Traumas, and Benzodiazepines Are Associated with Substance-Related Problems in Trauma Patients

Background: Trauma is commonly associated with substance-related problems, yet associations between specific substances and specific posttraumatic stress disorder symptoms (PTSSs) are understudied. We hypothesized that substance-related problems are associated with PTSS severities, interpersonal traumas, and benzodiazepine prescriptions. Methods: Using a cross-sectional survey methodology in a consecutive sample of adult outpatients with trauma histories (n = 472), we used logistic regression to examine substance-related problems in general (primary, confirmatory analysis), as well as alcohol, tobacco, and illicit drug problems specifically (secondary, exploratory analyses) in relation to demographics, trauma type, PTSSs, and benzodiazepine prescriptions. Results: After adjusting for multiple testing, several factors were significantly associated with substance-related problems, particularly benzodiazepines (AOR = 2.78; 1.99 for alcohol, 2.42 for tobacco, 8.02 for illicit drugs), DSM-5 PTSD diagnosis (AOR = 1.92; 2.38 for alcohol, 2.00 for tobacco, 2.14 for illicit drugs), most PTSSs (especially negative beliefs, recklessness, and avoidance), and interpersonal traumas (e.g., assaults and child abuse). Conclusion: In this clinical sample, there were consistent and strong associations between several trauma-related variables and substance-related problems, consistent with our hypotheses. We discuss possible explanations and implications of these findings, which we hope will stimulate further research, and improve screening and treatment

An adaptive community-based participatory approach to formative assessment with high schools for obesity intervention*.

BACKGROUND: In the emerging debate around obesity intervention in schools, recent calls have been made for researchers to include local community opinions in the design of interventions. Community-based participatory research (CBPR) is an effective approach for forming community partnerships and integrating local opinions. We used CBPR principles to conduct formative research in identifying acceptable and potentially sustainable obesity intervention strategies in 8 New Mexico school communities. METHODS: We collected formative data from 8 high schools on areas of community interest for school health improvement through collaboration with local School Health Advisory Councils (SHACs) and interviews with students and parents. A survey based on formative results was created to assess acceptability of specific intervention strategies and was provided to SHACs. Quantitative data were analyzed using descriptive statistics while qualitative data were evaluated using an iterative analytic process for thematic identification. RESULTS: Key themes identified through the formative process included lack of healthy food options, infrequent curricular/extracurricular physical activity opportunities, and inadequate exposure to health/nutritional information. Key strategies identified as most acceptable by SHAC members included healthier food options and preparation, a healthy foods marketing campaign, yearly taste tests, an after-school noncompetitive physical activity program, and community linkages to physical activity opportunities. CONCLUSION: An adaptive CBPR approach for formative assessment can be used to identify obesity intervention strategies that address community school health concerns. Eight high school SHACs identified 6 school-based strategies to address parental and student concerns related to obesity

Continental-scale dynamics of avian influenza in U.S. waterfowl are driven by demography, migration, and temperature

Emerging diseases of wildlife origin are increasingly spilling over into humans and domestic animals. Surveillance and risk assessments for transmission between these populations are informed by a mechanistic understanding of the pathogens in wildlife reservoirs. For avian influenza viruses (AIV), much observational and experimental work in wildlife has been conducted at local scales, yet fully understanding their spread and distribution requires assessing the mechanisms acting at both local, (e.g., intrinsic epidemic dynamics), and continental scales, (e.g., long-distance migration). Here, we combined a large, continental-scale data set on low pathogenic, Type A AIV in the United States with a novel network-based application of bird banding/recovery data to investigate the migration-based drivers of AIV and their relative importance compared to well-characterized local drivers (e.g., demography, environmental persistence). We compared among regression models reflecting hypothesized ecological processes and evaluated their ability to predict AIV in space and time using within and out-ofsample validation. We found that predictors of AIV were associated with multiple mechanisms at local and continental scales. Hypotheses characterizing local epidemic dynamics were strongly supported, with age, the age-specific aggregation of migratory birds in an area and temperature being the best predictors of infection. Hypotheses defining larger, network-based features of the migration processes, such as clustering or between-cluster mixing explained less variation but were also supported. Therefore, our results support a role for local processes in driving the continental distribution of AIV

Extinction intensity during Ordovician and Cenozoic glaciations explained by cooling and palaeogeography

International audienceA striking feature of the marine fossil record is the variable intensity of extinction during superficially similar climate transitions. Here we combine climate models and species trait simulations to explore the degree to which differing palaeogeographic boundary conditions and differing magnitudes of cooling and glaciation can explain the relative intensity of marine extinction during greenhouse-icehouse transitions in the Late Ordovician and the Cenozoic. Simulations modelled the response of virtual species to cooling climate using a spatially explicit cellular automaton algorithm. We find that palaeogeography alone may be a contributing factor, as identical changes in meridional sea surface temperature gradients caused greater extinction in Late Ordovician simulations than in Cenozoic simulations. Differences in extinction from palaeogeography are significant, but by themselves are insufficient to explain observed differences in extinction intensity. However, when simulations included inferred changes in continental flooding and interval-specific models of sea surface temperature, predicted differences in relative extinction intensity were more consistent with observations from the fossil record. Our results support the hypothesis that intense extinction in the Late Ordovician is partially attributable to exceptionally rapid and severe cooling compared to Cenozoic events