Avian influenza is a highly contagious viral disease, characterized by intense circulation in the wild waterbird reservoirs, with periodical introductions into the domestic poultry sector. AI viruses have been the source of devastating economic losses in the poultry industry over the last three decades, and have become a major veterinary and public health concern due to their zoonotic potential. The most emblematic illustration of this impact has been the emergence of the HPAI H5N1 virus in southern China in the mid-1990s, followed by its continental spread across East and Southeast Asia, and the unprecedented epidemics recorded in 2003–2004. More recently (from 2014 to 2017), several subtypes of HPAI (including H5N1, H5N6, H5N8) emerged in East Asia and spread intercontinentally, stressing the crucial role of this geographical hotspot as a source of new HPAI subtypes. The international dimension and the difficulty to effectively control those epidemics highlight the need for a global approach to HPAI surveillance and a comprehensive knowledge on epidemiology and patterns of the disease. This Research Topic aims at contributing to fill this gap. It includes ten papers which supplement the knowledge of the epidemiology of AI and offer new approaches on control strategies in various regions of the world.
This book focuses on the "Bird Flu: the new emerging infectious disease", a new health problem, and the aspects relating to the use of tropical medicine. It specifically covers the clinical aspects, scientific laboratory, public health, as well as the social sciences relating to this new important infectious disease. Mainly, the book presents summative data from the molecular to the population scales, as well as additional metanalysis for important topics. In addition, the diagnostic guideline and clinical practice guidelines of the mentioned conditions are detailed. There is still limited knowledge on this topic while the wider distribution of the disorder due to the globalisation can be expected.
Because of its high impact on both animal and human health, avian influenza has become a matter of increasing public concern and growing scientific interest within the last decade. This volume gives an overview of the most important results of these research efforts and provides information about the ecology and epidemiology of avian influenza with particular emphasis on recent H5N1 outbreaks in China, Siberia and Europe. Several articles deal with new vaccination strategies, the use of antivirals and other control measures to combat outbreaks of avian influenza. Further chapters illustrate that molecular biology, culminating in the generation of influenza viruses by recombinant DNA technology, was instrumental in unravelling the roles of the viral hemagglutinin and polymerase as well as cellular signalling pathways and innate immunity in pathogenesis and interspecies transmission. Finally, the threat of a pandemic originating from avian influenza viruses is illustrated by the example of the Spanish influenza of 1918.This comprehensive publication on avian influenza viruses and their relevance for human influenza will be of great value to all influenza virologists, molecular biologists, public health scientists, veterinary virologists, ecologists, and scientists engaged in drug design and vaccine development.
THE ESSENTIAL WORK IN TRAVEL MEDICINE -- NOW COMPLETELY UPDATED FOR 2018 As unprecedented numbers of travelers cross international borders each day, the need for up-to-date, practical information about the health challenges posed by travel has never been greater. For both international travelers and the health professionals who care for them, the CDC Yellow Book 2018: Health Information for International Travel is the definitive guide to staying safe and healthy anywhere in the world. The fully revised and updated 2018 edition codifies the U.S. government's most current health guidelines and information for international travelers, including pretravel vaccine recommendations, destination-specific health advice, and easy-to-reference maps, tables, and charts. The 2018 Yellow Book also addresses the needs of specific types of travelers, with dedicated sections on: · Precautions for pregnant travelers, immunocompromised travelers, and travelers with disabilities · Special considerations for newly arrived adoptees, immigrants, and refugees · Practical tips for last-minute or resource-limited travelers · Advice for air crews, humanitarian workers, missionaries, and others who provide care and support overseas Authored by a team of the world's most esteemed travel medicine experts, the Yellow Book is an essential resource for travelers -- and the clinicians overseeing their care -- at home and abroad.
Avian influenza, or 'bird flu', is a contagious disease of animals caused by viruses that normally infect only birds and, less commonly, pigs. Avian influenza viruses are highly species-specific, but have, on rare occasions, crossed the species barrier to infect humans. In domestic poultry, infection with avian influenza viruses causes two main forms of disease, distinguished by low and high extremes of virulence. The so-called 'low pathogenic' form commonly causes only mild symptoms (ruffled feathers, a drop in egg production) and may easily go undetected. The highly pathogenic form is far more dramatic. It spreads very rapidly through poultry flocks, causes disease affecting multiple internal organs, and has a mortality that can approach 100%, often within 48 hours.
Avian influenza, sometimes avian flu, and commonly called bird flu, refers to "influenza caused by viruses adapted to birds". Of greatest concern is highly pathogenic avian influenza (HPAI). These influenza viruses occur naturally among birds. Wild birds world-wide carry the viruses in their intestines, but usually do not get sick from them. However, avian influenza is very contagious among birds and can make some domesticated birds, including chickens, ducks, and turkeys, very ill. Infected birds shed influenza virus in their saliva, nasal secretions, and faeces. Susceptible birds become infected when they have contact with contaminated secretions or excretions or with surfaces that are contaminated with secretions or excretions from infected birds. The risk from avian influenza is generally low for most people, because the viruses do not usually infect humans. However, confirmed cases of human infection from several subtypes of avian influenza infection have been reported since 1997. The spread of avian influenza viruses from one ill person to another has been reported very rarely, and has been limited, inefficient and unsustained. This important book gathers the latest research from around the globe in this field.
This dissertation, "Molecular Epidemiology of Avian Influenza Viruses From Southeastern China" by 錢寶生, Po-san, Mario, Chin, was obtained from The University of Hong Kong (Pokfulam, Hong Kong) and is being sold pursuant to Creative Commons: Attribution 3.0 Hong Kong License. The content of this dissertation has not been altered in any way. We have altered the formatting in order to facilitate the ease of printing and reading of the dissertation. All rights not granted by the above license are retained by the author. Abstract: Abstract of thesis entitled Molecular Epidemiology of Avian Influenza Viruses from Southeastern China by Chin Po San, Mario for the degree of Doctor of Philosophy at The University of Hong Kong in January 2003 The H5N1 'bird flu' incident that claimed six lives in Hong Kong in 1997 was generally considered to have been an incipient pandemic. Chicken in the live poultry markets were the principal source of the highly pathogenic H5N1 (H5N1/97) viruses raising the possibility that terrestrial poultry could become a source of pandemic influenza viruses. To explore this hypothesis, influenza virus surveillance was conducted in Hong Kong on wild aquatic birds and on terrestrial poultry from southeastern China. Influenza virus surveillance of wild aquatic birds at the Mai Po Nature Reserve from March 1999 to February 2001 yielded a lone H3N8 virus from 1077 faecal samples. Thus, these birds are not a major reservoir of influenza viruses and are unlikely to be responsible for the viruses isolated from domestic poultry in Hong Kong and immediate southeastern China. By contrast, 4286 faecal samples from eight types of terrestrial poultry in live-poultry retail markets from April 1999 to May 2000 yielded 209 H9N2 viruses from seven types predominantly quail and six H6N1 viruses from quail, chukar and pheasant. These H9N2 viruses have six H5N1/97-like genes paving the way for genetic characterization of the H6N1 viruses. Sequence and phylogenetic analyses revealed that the H6N1 viruses possess seven gene segments that are closely related to those of the H5N1/97 viruses and that the H6 HA gene may have been of regional duck origin. The N1 NA has a 19-amino- acid deletion in the stalk characteristic of the N1 of H5N1/97 viruses, a feature possibly associated with adaptation to terrestrial poultry. Similar to the H5N1/97 viruses, these H6N1 viruses possess six human influenza virus-like amino acids in the PB2, NP and M2 proteins highlighting their enhanced potential for infecting humans. The marketing system of poultry in southeastern China which places poultry and humans in close proximity may enhance interspecies transmission of H6N1 viruses to humans. Co-circulation of H6N1 viruses with other precursors of the H5N1/97 virus, A/Goose/Guangdong/1/96 (H5N1)-like and A/Quail/HK/G1/97 (H9N2)-like viruses, in terrestrial poultry raises the possibility of the generation of H5N1/97-like viruses or other dangerous reassortants in this region. This possibility is reinforced by the isolation of a naturally occurring H6N1 reassortant virus from a pheasant with five H5N1/97-like gene segments (PB2, PB1, PA, NA and M). Moreover, analyses of the rates of amino acid substitution of the internal protein genes suggested that the H6N1 and H9N2 viruses might have been present in terrestrial poultry before the H5N1/97 outbreak in accordance with their apparent precursor role. In all, this thesis has shown that terrestrial poultry in southeastern China, particularly quail, are a reservoir for H6N1 viruses (increasingly so) in addition to H9N2 viruses. H6N1 alone has the potential to donate the seven requisite genes to generate an H5N1/97-like virus. It provided further evidence to uphold the hypothesis that southern China is an epicentre for the emergence of pandemic influenza viruses underscoring the importance of animal influenza virus surveillance there. Prospective action toward influenza pandemic preparedne
Asia, Africa and Europe have in the recent years witnessed outbreaks of Avian Influenza resulting in the deaths and culling of over 200 million poultry resulting in huge economic losses besides adversely affecting farmers, households, the poultry industry, tourism and trade relations countries and nations. Many countries in the South-East Asia region are on the flight paths of migrating birds, some of which could be carrying Avian Influenza virus. In view of the epidemiological situation, all countries in the region are vulnerable to the influenza pandemic. Threat of world influenza pandemic has never been imminent. To combat this grave threat, it is essential for countries to be well prepared. Experts predict it is only a matter of time before a bird flu strain will mutate and become transmissible between humans. Once that happens, a pandemic like the Spanish flu that resulted in over 50 million deaths, overwhelming hospital and medical services could be inevitable. This book includes a detailed glossary of terms and a comprehensive index to clarify all the technical and general concepts about this deadly virus. WHO guidelines are provided in detail. The prevention and preparedness of activities that facilitate the response and recovery during and after influenza pandemic are important aspects that are included in this book.
With the growing global fear of a major pandemic, avian influenza (AI) virus research has greatly increased in importance. In Avian Influenza Virus, an expert team of researchers and diagnosticians examine the fundamental, yet essential, virological methods for AI virus research and diagnostics as well as some of the newest molecular procedures currently used for basic and applied research. They present exciting, cutting-edge new methods that focus both on studying the virus itself and on work with avian hosts, an area greatly lacking in research.
This book provides salient information on all aspects of influenza/flu viruses affecting animals and humans. It specifically reviews the properties and replication of influenza viruses; their evolution and emergence; epidemiology; role of migratory birds in disease transmission; clinical signs in humans, animals and poultry; pathogenesis and pathogenicity; public health importance and potential threats; diagnosis; prevention and control measures; and pandemic preparedness. Influenza/flu viruses evolve continuously and jump species causing epidemics as well as pandemics in both human and animals. During the past 150 years, various strains of influenza virus like the Spanish flu, Asian flu, Hong Kong flu, bird flu and swine flu were responsible for high mortality in humans as well as birds. High mutation rates, antigenic shifts, drifts, reassortment phenomena, and the development of antiviral drug resistance all contribute to ineffective chemotherapy and vaccines against influenza viruses. Due to their devastating nature, high zoonotic implications and high mortality in humans and poultry, they have a severe impact on the socioeconomic status of countries. Disease awareness, rapid and accurate diagnosis, surveillance, strict biosecurity, timely adoption of appropriate preventive and control measures and pandemic preparedness are crucial to help reduce virus transmission, thus reducing clinical cases, deaths and pandemic threats.
