Risk assessment applied to Spain's prevention strategy against highly pathogenic avian influenza virus H5N1

Risk of Introduction of Infectious Animal Diseases for Europe Based on the Health Situation of North Africa and the Arabian Peninsula

The current growth of the human population, the intensification of animal production, climate change or globalization favors an increase in the transmission of infectious diseases. Risk analysis is the tool that allows the identification of the factors involved in the introduction and the spread of infectious diseases. The main objective of this work is to evaluate the risk of entry of animal infectious zoonotic and non-zoonotic diseases from North Africa and the Arabian Peninsula to countries of the European Union. A probabilistic formulation has been developed to obtain the probabilities of introduction of diseases associated with each possible route of entry in the European Union. The results show that, among the infectious diseases analyzed in this study, avian influenza and Newcastle disease are the ones with a higher risk of entry in the European Union and the wild bird's migration is the route with greater impact. It is confirmed a moderate probability of entry of some vector-borne diseases, bluetongue and epizootic haemorrhagic disease, through wind flow from Morocco, Algeria and Tunisia. Due to the absence of live dromedary movement to Europe, the more likely way of entry of the Middle East respiratory syndrome is through the infected people movement from Saudi Arabia, Kuwait, Qatar and Oman. This study includes different methodologies. A model of vectors dispersion in wind currents has been established to assess the risk of introduction of vector borne diseases. It is applicable both in animal health and public health. A periodical update would be useful to obtain a periodically updated risk analysis and to allow early detection of potential hazard with an increased risk over the previous years.

Systematic review of surveillance systems and methods for early detection of exotic, new and re-emerging diseases in animal populations

In this globalized world, the spread of new, exotic and re-emerging diseases has become one of the most important threats to animal production and public health. This systematic review analyses conventional and novel early detection methods applied to surveillance. In all, 125 scientific documents were considered for this study. Exotic (n = 49) and re-emerging (n = 27) diseases constituted the most frequently represented health threats. In addition, the majority of studies were related to zoonoses (n = 66). The approaches found in the review could be divided in surveillance modalities, both active (n = 23) and passive (n = 5); and tools and methodologies that support surveillance activities (n = 57). Combinations of surveillance modalities and tools (n = 40) were also found. Risk-based approaches were very common (n = 60), especially in the papers describing tools and methodologies (n = 50). The main applications, benefits and limitations of each approach were extracted from the papers. This information will be very useful for informing the development of tools to facilitate the design of cost-effective surveillance strategies. Thus, the current literature review provides key information about the advantages, disadvantages, limitations and potential application of methodologies for the early detection of new, exotic and re-emerging diseases.

Risk assessment of the introduction of H5N1 highly pathogenic avian influenza as a tool to be applied in prevention strategy plan

Risks of the introduction of highly pathogenic avian influenza (HPAI) H5N1 through migratory birds to the main wintering site for wild birds in southern Brazil and its consequences were assessed. Likelihoods were estimated by a qualitative scale ranging from negligible to high. Northern migrants that breed in Alaska and regularly migrate to South America (primary Charadriiformes) can have contact with birds from affected areas in Asia. The likelihood of the introduction of HPAI H5N1 through migratory birds was found to be very low as it is a probability conditioned to successful transmission in breeding areas and the probabilities of an infected bird migrating and shedding the virus as far as southern Brazil. The probability of wild species becoming exposed to H5N1-infected birds is high as they nest with northern migrants from Alaska, whereas for backyard poultry it is moderate to high depending on proximity to wetlands and the presence of species that could increase the likelihood of contact with wild birds such as domestic duck. The magnitude of the biological and economic consequences of successful transmission to poultry or wild birds would be low to severe depending on the probability of the occurrence of outbreak scenarios described. As a result, the risk estimate is greater than negligible, and HPAI H5N1 prevention strategy in the region should always be carefully considered by the veterinary services in Brazil.

Bird migration and risk for H5N1 transmission into Qinghai Lake, China

The highly pathogenic avian influenza H5N1 virus still cause devastating effects to humans, agricultural poultry flocks, and wild birds. Wild birds are also detected to carry H5N1 over long distances and are able to introduce it into new areas during migration. In this article, our objective is to provide lists of bird species potentially involved in the introduction of highly pathogenic avian influenza H5N1 in Qinghai Lake, which is an important breeding and stopover site for aquatic birds along the Central Asian Flyway. Bird species were classified according to the following behavioral and ecological factors: migratory status, abundance, degree of mixing species and gregariousness, and the prevalence rate of H5N1 virus. Most of the high-risk species were from the family Anatidae, order Anseriformes (9/14 in spring, 11/15 in fall). We also estimated the relative risk of bird species involved by using a semi-quantitative method; species from family Anatidae accounted for over 39% and over 91% of the total risk at spring and fall migration periods, respectively. Results also show the relative risk for each bird aggregating site in helping to identify high-risk areas. This work may also be instructive and meaningful to the avian influenza surveillance in the breeding, stopover, and wintering sites besides Qinghai Lake along the Central Asian Flyway.

Practical high pathogenicity avian influenza first-response training exercises

The response to an avian influenza outbreak, especially highly pathogenic avian influenza (HPAI), should focus on four basic principles: 1) protect humans first, 2) protect animals 3) contain the virus, and 4) ensure that the outbreak remains a single event, by preparing response teams to work together effectively through advance training. The Stamping Out Pandemic and Avian Influenza (STOP AI) project is a U.S. Agency for International Development-funded global activity. STOP AI has designed and conducted practical, experiential training exercises that engage participants in simulated experiences that enhance their confidence and ability to apply these principles during a real HPAI outbreak. This article describes three specific exercises: 1) wearing and removing personal protective equipment (PPE) in a controlled environment, 2) site zoning, and 3) a planning and resource mapping exercise staged in Poultopia--a fictional region in a developing country. The PPE activity emphasizes the physical challenges of working in full PPE and the importance of proper equipment removal. In the zoning exercise, response teams focus on the areas and the tasks required by setting up a clean area, transit corridor, infected/culling area, and nontransit areas at a farm, village, or other location. In Poultopia, participants must determine where surveillance should occur, decide where roadblocks should be placed during an outbreak, choose which birds to cull first and determine how to dispose of them safely, ascertain the types of personnel and equipment needed, and assess timing issues. The Poultopia scenarios are adapted to the conditions of the region where the training takes place, thus adding to their realism and utility. The practical techniques described here have been taught successfully through STOP AI in more than 30 countries in Europe, Asia, and Africa.

Risk of introduction of H5N1 HPAI from Europe to Spain by wild water birds in autumn

Highly pathogenic avian influenza (HPAI) subtype H5N1 continues to circulate across Eurasia and Africa since its unprecedented rapid spread in 2005. Diffusion by wild bird movements has been evidenced in the European Union in 2006 and 2007. Spain is an important wintering quarter for aquatic birds from northern latitudes, so identifying the critical areas and species where an outbreak is prone to happen is necessary. This work presents an assessment of the risk of introduction of H5N1 HPAI in Spain by aquatic wild birds estimating a relative risk value per province. For this purpose, an assessment of the release and exposure to the risk of infection with H5N1 HPAI of 25 selected water bird species has been carried out. Parameters considered in the assessment include H5N1 HPAI notifications from 2006 to 2008 and factors that favour the occurrence or persistence of H5N1 HPAI (wetlands' surface, low temperatures), together with aquatic wild birds' movements parameters (departure, destination, stop-overs, abundance) and parameters relative to the susceptible population in Spain: poultry density and wild aquatic abundance. Results show the relative risk for each Spanish province of experiencing H5N1 HPAI introduced by wild aquatic birds helping to identify higher risk areas.

Emerging viral zoonoses: frameworks for spatial and spatiotemporal risk assessment and resource planning

Spatial epidemiological tools are increasingly being applied to emerging viral zoonoses (EVZ), partly because of improving analytical methods and technologies for data capture and management, and partly because the demand is growing for more objective ways of allocating limited resources in the face of the emerging threat posed by these diseases. This review documents applications of geographical information systems (GIS), remote sensing (RS) and spatially-explicit statistical and mathematical models to epidemiological studies of EVZ.

Landscape epidemiology uses statistical associations between environmental variables and diseases to study and predict their spatial distributions. Phylogeography augments epidemiological knowledge by studying the evolution of viral genetics through space and time. Cluster detection and early warning systems assist surveillance and can permit timely interventions. Advanced statistical models can accommodate spatial dependence present in epidemiological datasets and can permit assessment of uncertainties in disease data and predictions. Mathematical models are particularly useful for testing and comparing alternative control strategies, whereas spatial decision-support systems integrate a variety of spatial epidemiological tools to facilitate widespread dissemination and interpretation of disease data. Improved spatial data collection systems and greater practical application of spatial epidemiological tools should be applied in real-world scenarios.