The Geographical Spread of Avian Influenza A (H5N1): Panzootic Transmission (December 2003–May 2006), Pandemic Potential, and Implications

Molecular Characterization of Non-H5 and Non-H7 Avian Influenza Viruses from Non-Mallard Migratory Waterbirds of the North American Flyways, 2006-2011

The surveillance of migratory waterbirds (MWs) for avian influenza virus (AIV) is indispensable for the early detection of a potential AIV incursion into poultry. Surveying AIV infections and virus subtypes in understudied MW species could elucidate their role in AIV ecology. Oropharyngeal-cloacal (OPC) swabs were collected from non-mallard MWs between 2006 and 2011. OPC swabs (n = 1158) that molecularly tested positive for AIV (Cts ≤ 32) but tested negative for H5 and H7 subtypes were selected for virus isolation (VI). The selected samples evenly represented birds from all four North American flyways (Pacific, Central, Mississippi, and Atlantic). Eighty-seven low pathogenic AIV isolates, representing 31 sites in 17 states, were recovered from the samples. All isolates belonged to the North American lineage. The samples representing birds from the Central Flyway had the highest VI positive rate (57.5%) compared to those from the other flyways (10.3-17.2%), suggesting that future surveillance can focus on the Central Flyway. Of the isolates, 43.7%, 12.6%, and 10.3% were obtained from blue-winged teal, American wigeon, and American black duck species, respectively. Hatch-year MWs represented the majority of the isolates (70.1%). The most common H and N combinations were H3N8 (23.0%), H4N6 (18.4%), and H4N8 (18.4%). The HA gene between non-mallard and mallard MW isolates during the same time period shared 85.5-99.5% H3 identity and 89.3-99.7% H4 identity. Comparisons between MW (mallard and non-mallard) and poultry H3 and H4 isolates also revealed high similarity (79.0-99.0% and 88.7-98.4%), emphasizing the need for continued AIV surveillance in MWs.

UK flockdown: A survey of smallscale poultry keepers and their understanding of governmental guidance on highly pathogenic avian influenza (HPAI)

The scale of the current outbreak of highly pathogenic avian influenza (HPAI) due to the A/H5N1 virus in the United Kingdom is unprecedented. In addition to its economic impact on the commercial poultry sector, the disease has devastated wild bird colonies and represents a potential public health concern on account of its zoonotic potential. Although the implementation of biosecurity measures is paramount to reducing the spread of HPAI in domestic and commercial settings, little is known about the attitudes and perspectives of backyard poultry keepers, who often keep their flocks in close proximity to the public. A large nationwide survey of backyard poultry keepers was undertaken in December 2021-March 2022, contemporaneous with the enforcement of an Avian Influenza Prevention Zone (AIPZ) and additional housing measures in England, Scotland and Wales. The survey explored keepers' understanding of the clinical manifestations of HPAI, compliance with housing and biosecurity measures, attitudes towards obligatory culling on confirmation of HPAI in their flocks, and the potential use of vaccination to control HPAI. Summary statistical analysis of the closed question responses was supplemented with qualitative data analysis and corpus linguistic approaches to draw out key themes and salient patterns in responses to open text questions. Survey responses were received from 1559 small-scale poultry keepers across the United Kingdom. Awareness of the HPAI outbreak was very high (99.0%). The majority of respondents learned of it via social media (53%), with Defra (49.7%), British Hen Welfare Trust (33.8%) and the APHA (22.0%) identified as the principal sources of information. Analysis revealed that backyard keepers lacked knowledge of the clinical signs of avian influenza and legal requirements relating to compliance with biosecurity measures. Some respondents dismissed the seriousness of HPAI and were unwilling to comply with the measures in force. The issue of obligatory culling proved highly emotive, and some expressed a lack of trust in authorities. Most respondents (93.1%) indicated a willingness to pay for vaccination if the option was available. Communications on biosecurity measures that are relevant to large-scale industrial setups are inappropriate for backyard contexts. Understanding the barriers that backyard keepers face is essential if official agencies are to communicate biosecurity information effectively to such groups. Lack of trust in authorities is likely to make elimination of the virus in the UK difficult. We make recommendations for tailoring HPAI-related information for backyard contexts, to aid future HPAI control measures in the UK.

New Patterns for Highly Pathogenic Avian Influenza and Adjustment of Prevention, Control and Surveillance Strategies: The Example of France

From 2020 up to summer 2023, there was a substantial change in the situation concerning the high pathogenic avian influenza (HPAI) virus in Europe. This change concerned mainly virus circulation within wildlife, both in wild birds and wild mammals. It involved the seasonality of HPAI detections, the species affected, excess mortality events, and the apparent increased level of contamination in wild birds. The knock-on effect concerned new impacts and challenges for the poultry sector, which is affected by repeated annual waves of HPAI arriving with wild migratory birds and by risks due to viral circulation within resident wild birds across the year. Indeed, exceeding expectations, new poultry sectors and production areas have been affected during the recent HPAI seasons in France. The HPAI virus strains involved also generate considerable concern about human health because of enhanced risks of species barrier crossing. In this article, we present these changes in detail, along with the required adjustment of prevention, control, and surveillance strategies, focusing specifically on the situation in France.

Exploring the responses of smallscale poultry keepers to avian influenza regulations and guidance in the United Kingdom, with recommendations for improved biosecurity messaging

Understanding how smallscale ('backyard') poultry keepers interpret and respond to governmental directives designed to reduce the transmission of highly pathogenic avian influenza (HPAI) is of paramount importance in preparing for future HPAI outbreaks. Qualitative insights from open questions in an online survey conducted during the 2021-22 HPAI season (1,559 responses) shed light on smallscale poultry keepers' understanding of, and responses to, governmental directives to control HPAI exposure and onwards transmission. A follow-up participatory workshop (21 participants) explored the HPAI-related information sources used by smallscale poultry keepers, their trust in these sources, perceptions of HPAI-related risk, and interpretation of, opinions on and adherence to government regulations and communications regarding biosecurity and housing measures. This paper draws on a multi-scale behaviour change model to explore barriers to compliance with HPAI-related regulations. Insights from behaviour settings theory reveal how poultry-keeping settings and routines might be 'disrupted' and 're-configured' to improve long-term biosecurity and reduce the risk of HPAI exposure. The findings highlight the need for HPAI-related guidance that is tailored to smallscale poultry keepers. This guidance should include clear action points and simple, practical, affordable and sustainable suggestions for improving compliance with biosecurity measures.

Economic globalization and the COVID-19 pandemic: global spread and inequalities

In just a few weeks, COVID-19 has become a global crisis and there is no longer any question of it being a major pandemic. The spread of the disease and the speed of transmission need to be squared with the forms and characteristics of economic globalization, disparities in development between the world's different regions and the highly divergent degree of their interconnectedness. Combining a geographic approach based on mapping the global spread of the virus with the collection of data and socio-economic variables, we drew up an OLS model to identify the impact of certain socio-economic factors on the number of cases observed worldwide. Globalization and the geography of economic relations were the main drivers of the spatial structuring and speed of the international spread of the COVID-19.

Social capital's impact on COVID-19 outcomes at local levels

Over the past thirty years, disaster scholars have highlighted that communities with stronger social infrastructure-including social ties that enable trust, mutual aid, and collective action-tend to respond to and recover better from crises. However, comprehensive measurements of social capital across communities have been rare. This study adapts Kyne and Aldrich's (Risk Hazards Crisis Public Policy 11, 61-86, 2020) county-level social capital index to the census-tract level, generating social capital indices from 2011 to 2018 at the census-tract, zipcode, and county subdivision levels. To demonstrate their usefulness to disaster planners, public health experts, and local officials, we paired these with the CDC's Social Vulnerability Index to predict the incidence of COVID-19 in case studies in Massachusetts, Wisconsin, Illinois, and New York City. We found that social capital predicted 41-49% of the variation in COVID-19 outbreaks, and up to 90% with controls in specific cases, highlighting its power as diagnostic and predictive tools for combating the spread of COVID.

Bowling alone or distancing together? The role of social capital in excess death rates from COVID19

Much attention on the spread and impact of the ongoing pandemic has focused on institutional factors such as government capacity along with population-level characteristics such as race, income, and age. This paper draws on a growing body of evidence that bonding, bridging, and linking social capital - the horizontal and vertical ties that bind societies together - impact public health to explain why some U.S. counties have seen higher (or lower) excess deaths during the COVID19 pandemic than others. Drawing on county-level reports from the Centers for Disease Control and Prevention (CDC) since February 2020, we calculated the number of excess deaths per county compared to 2018. Starting with a panel dataset of county observations over time, we used coarsened exact matching to create smaller but more similar sets of communities that differ primarily in social capital. Controlling for several factors, including politics and governance, health care quality, and demographic characteristics, we find that bonding and linking social capital reduce the toll of COVID-19 on communities. Public health officials and community organizations should prioritize building and maintaining strong social ties and trust in government to help combat the pandemic.

The dual effect of social ties on COVID-19 spread in Japan

We investigate why some communities experience worse COVID-19 outcomes than others. Past studies have linked the resilience of communities against crisis to social vulnerability and the capacity of local governments to provide public goods and services like health care. Disaster studies, which frequently examine the effect of social ties and mobility, may better help illuminate the current spread of COVID-19. We analyze Japan's 47 prefectures from February 12 to August 31 using 62,722 individual confirmed cases of COVID-19, paired with daily tallies of aggregate Facebook user movement among neighborhoods. Controlling for mobility levels, health care systems, government finance, gender balance, age, income, and education levels of communities, our analysis indicates that areas with strong linking social ties see no or far lower levels of COVID-19 case rates initially. However, case fatality rates rise in such communities once the disease enters as they lack horizontal (bonding) ties which can mitigate its health impacts. We anticipate this study to be a starting point for broader studies of how social ties and mobility influence COVID-19 outcomes worldwide along with shining a light on how different types of social relationships play different roles as a crisis or disaster progresses.

Mega Regions and Pandemics

The ongoing COVID-19 crisis has put the relationship between spatial structure and disease exposure into relief. Here, we propose that mega regions - clusters of metropolitan regions like the Acela Corridor in the United States are more exposed to diseases earlier in pandemics. We review standard accounts for the benefits and costs of locating in such regions before arguing that pandemic risk is higher there on average. We test this mega region exposure theory with a study of the US urban system. Our results indicate that American mega regions have born the early brunt of the disease, and that three mega regions are hotspots. From this standpoint, the extent more than the intensity of New York's urbanization may be implicated in its COVID-19 experience. We conclude that early pandemic risk is a hitherto unrecognised diseconomy operating in mega regions.

[Using geo-intelligence to estimate risk of introduction of influenza type A in MexicoCenário de risco de introdução do vírus da influenza A no México estimado com o uso de inteligência geográfica]

Objetivo.

Estimar el escenario potencial probabilístico de introducción del agente causal de la influenza tipo A en México mediante geointeligencia sanitaria.

Métodos.

Estudio ecológico en el que consideran 1 973 brotes de influenza con alto grado de patogenicidad en el mundo durante el período 2014-2016. Se desarrolló un modelado geoespacial con herramientas de la geointeligencia, como la representación espacial, modelo de conexidad, caracterización espacial de la fuente de inoculo con el modelo de máxima entropía y la curva característica de operación receptora (COR) mediante la evaluación espacial multicriterio y se validó con el índice de Moran y la regresión geográficamente ponderada.

Resultados.

Se estimaron las isocronas de riesgo sanitario con una distancia de 548 km y su crecimiento exponencial; hasta la cuarta isócrona se identificaron las costas este y oeste de Estados Unidos de América (EEUU) y una porción de América Central como posible superficie que favorece la introducción del patógeno. Se obtuvo, también, una curva COR = 0,923, se identificaron dos períodos de riesgo de introducción (setiembre-marzo) y (abril-agosto) con trayectorias de norte-sur y sur-norte respectivamente, con alta autocorrelación positiva para el modelado geoespacial, y se estimó un escenario donde más de la mitad de México se encuentra en un riesgo alto de introducción, con 78 millones de personas expuestas. Se identificó una asociación positiva entre las áreas de riesgo significativo (P < 0,001).

Conclusión.

Se evidencia que más de 50% del territorio mexicano se encuentra en riesgo de introducción del agente causal de la influenza tipo A, con aproximadamente 70% de la población expuesta.

Spatial, temporal and genetic dynamics of highly pathogenic avian influenza A (H5N1) virus in China

BACKGROUND

The spatial spread of H5N1 avian influenza, significant ongoing mutations, and long-term persistence of the virus in some geographic regions has had an enormous impact on the poultry industry and presents a serious threat to human health.

METHODS

We applied phylogenetic analysis, geospatial techniques, and time series models to investigate the spatiotemporal pattern of H5N1 outbreaks in China and the effect of vaccination on virus evolution.

RESULTS

Results showed obvious spatial and temporal clusters of H5N1 outbreaks on different scales, which may have been associated with poultry and wild-bird transmission modes of H5N1 viruses. Lead-lag relationships were found among poultry and wild-bird outbreaks and human cases. Human cases were preceded by poultry outbreaks, and wild-bird outbreaks were led by human cases. Each clade has gained its own unique spatiotemporal and genetic dominance. Genetic diversity of the H5N1 virus decreased significantly between 1996 and 2011; presumably under strong selective pressure of vaccination. Mean evolutionary rates of H5N1 virus increased after vaccination was adopted in China. A clear signature of positively selected sites in the clade 2.3.2 virus was discovered and this may have resulted in the emergence of clade 2.3.2.1.

CONCLUSIONS

Our study revealed two different transmission modes of H5N1 viruses in China, and indicated a significant role of poultry in virus dissemination. Furthermore, selective pressure posed by vaccination was found in virus evolution in the country.

Using knowledge fusion to analyze avian influenza H5N1 in East and Southeast Asia

Highly pathogenic avian influenza (HPAI) H5N1, a disease associated with high rates of mortality in infected human populations, poses a serious threat to public health in many parts of the world. This article reports findings from a study aimed at improving our understanding of the spatial pattern of the highly pathogenic avian influenza, H5N1, risk in East-Southeast Asia where the disease is both persistent and devastating. Though many disciplines have made important contributions to our understanding of H5N1, it remains a challenge to integrate knowledge from different disciplines. This study applies genetic analysis that identifies the evolution of the H5N1 virus in space and time, epidemiological analysis that determines socio-ecological factors associated with H5N1 occurrence, and statistical analysis that identifies outbreak clusters, and then applies a methodology to formally integrate the findings of the three sets of methodologies. The present study is novel in two respects. First it makes the initiative attempt to use genetic sequences and space-time data to create a space-time phylogenetic tree to estimate and map the virus' ability to spread. Second, by integrating the results we are able to generate insights into the space-time occurrence and spread of H5N1 that we believe have a higher level of corroboration than is possible when analysis is based on only one methodology. Our research identifies links between the occurrence of H5N1 by area and a set of socio-ecological factors including altitude, population density, poultry density, and the shortest path distances to inland water, coastlines, migrating routes, railways, and roads. This study seeks to lay a solid foundation for the interdisciplinary study of this and other influenza outbreaks. It will provide substantive information for containing H5N1 outbreaks.

The geography of institutional psychiatric care in France 1800-2000: historical analysis of the spatial diffusion of specialised facilities for institutional care of mental illness

As in other European countries, specialised psychiatric hospitals were established throughout France during the 19th Century. The construction of these hospitals can be considered as the concrete expression of a therapeutic innovation which recognized insanity as an illness that could be treated in such specialised institutions. The spatial diffusion of these innovative institutions through 19th and 20th century France is analysed and we explore how far this can be understood through theories of diffusion of innovations including geographical models of hierarchical and expansion diffusion (or whether other conceptual models are more appropriate). The research reported here particularly focuses on the period 1800-1961. It involved the construction of an original historical database of both psychiatric hospitals and information on the cities where these institutions were located. This was used to examine and interpret the different phases of development of psychiatric institutions and the parts of the country and types of geographical setting where they were concentrated. A multiple correspondence analysis was then performed to examine the connections between different aspects of the diffusion process. The study shows the limitations of classical models of spatial diffusion, which are found to be consistent with some, but not all aspects of the development of psychiatric institutions in France. An alternative political ecology approach seems more appropriate to conceptualise the various processes involved; national policies, social representations, medicalisation of care of mental illness, and urban and economic growth all seem to be associated with the emergence of a variable and complex pattern. This paper also opens a large field of research. Compared with other western countries, the geography of French psychiatric care is relatively under-researched, although there has been a strong spatial dimension to mental health policy in the country. This analysis provides a context for studies of more contemporary processes of French deinstitutionalisation, which is strongly structured by the past heritage of these large asylum facilities.