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The role of animal feed as a vehicle for the transport and transmission of viral diseases was first identified in 2014 during the porcine epidemic diarrhoea virus epidemic in North America. Since the identification of this novel risk factor, scientists have conducted numerous studies to understand its relevance. Over the past few years, the body of scientific evidence supporting the reality of this risk has grown substantially. In addition, numerous papers describing actions and interventions designed to mitigate this risk have been published. Therefore, the purpose of this paper is to review the literature on the risk of feed (what do we know) and the protocols developed to reduce this risk (what do we do) in an effort to develop a comprehensive document to raise awareness, facilitate learning, improve the accuracy of risk assessments and to identify knowledge gaps for future studies. [ABSTRACT FROM AUTHOR]

Although the effective transmission of the H5N1 virus from humans to humans has yet to be further observed, humans are at increased risk of a pandemic caused by H5N1. In order to fully evaluate the seroprevalence and risk factor of highly pathogenic avian influenza A (H5N1) virus infection among in mainland China, we performed a systematic review and meta‐analysis. In this review, we searched literature on the seroprevalence of H5N1 infection among humans in mainland China from 1 January 1997 to 20 October 2018 in English and Chinese databases, including PubMed, Google scholar, Cochrane library, Clinical Trial, VIP, CNKI and WanFang database. We made a selection according to the title and the abstract of paper, and then, we excluded duplicated literature, and data incomplete literature according to the exclusion criteria we formulated. Finally, we extracted how many humans have H5N1 infection from the obtained studies to establish the seroprevalence of H5N1 infection among humans in mainland China. A total of 56 studies (including data of 35,159 humans) were compliant with our criteria. In China, the overall seroprevalence of H5N1 infection among humans was 2.45% (862/35,159), while the seroprevalence of H5N1 infection among humans from central China was 7.32% (213/2,911), higher than those in other regions of China. The seroprevalence of H5N1 infection was associated with test method, sampling time and demographic characteristics of humans. However, there was no significant difference in the effect of gender on the seroprevalence of H5N1 among humans in China. The purpose of this review was to better understand the real infection rate of H5N1 virus among humans and evaluate the potential risk factors for the zoonotic spread of H5N1 virus to humans. Sufficient epidemiological data are important to explore and understand the prevalent status of AIVs throughout the country and to disease control. [ABSTRACT FROM AUTHOR]

Influenza A virus, the H9N2 subtype, is an avian influenza virus that has long been circulating in the worldwide poultry industry and is occasionally found to be transmissible to humans. Evidence from genomic analysis suggests that H9N2 provides the genes for the H5N1 and H7N9 subtypes, which have been found to infect mammals and pose a threat to human health. However, due to the lack of a structural model of the interaction between H9N2 and host cells, the mechanism of the extensive adaptability and strong transformation capacity of H9N2 is not fully understood. In this paper, we collected 40 representative H9N2 virus samples reported recently, mainly in China and neighboring countries, and investigated the interactions between H9N2 hemagglutinin and the mammalian receptor, the polysaccharide α-2,6-linked lactoseries tetrasaccharide c, at the atomic level using docking simulation tools. We categorized the mutations of studied H9N2 hemagglutinin according to their effects on ligand-binding interactions and the phylogenetic analysis. The calculations indicated that all the studied H9N2 viruses can establish a tight binding with LSTc although the mutations caused a variety of perturbations to the local conformation of the binding pocket. Our calculations suggested that a marginal equilibrium is established between the conservative ligand-receptor interaction and the conformational dynamics of the binding pocket, and it might be this equilibrium that allows the virus to accommodate mutations to adapt to a variety of environments. Our results provided a way to understand the adaptive mechanisms of H9N2 viruses, which may help predict its propensity to spread in mammals. • 40 HA mutant structures of H9N2 avian influenza virus circulating mostly in China were investigated. • Mutations in 9 of 100 amino acids of the HA protein were found critical to virus adaptability. • Compared with Q226-HA, the binding orientation of L226-HA to mammalian receptors was more stable and concentrated. [ABSTRACT FROM AUTHOR]

Cross-sectional surveys conducted in Thailand and China after the outbreaks of the avian influenza A H5N1 and H7N9 viruses show a high degree of awareness of human avian influenza in both urban and rural populations, a higher level of proper hygienic practice among urban residents, and in particular a dramatically reduced number of visits to live markets in urban population after the influenza A H7N9 outbreak in China in 2013. In this paper, taking into account the psychological effect toward avian influenza in the human population, a bird-to-human transmission model in which the avian population exhibits saturation effect is constructed. The dynamical behavior of the model is studied by using the basic reproduction number. The results demonstrate that the saturation effect within avian population and the psychological effect in human population cannot change the stability of equilibria but can affect the number of infected humans if the disease is prevalent. Numerical simulations are given to support the theoretical results and sensitivity analyses of the basic reproduction number in terms of model parameters that are performed to seek for effective control measures for avian influenza. [ABSTRACT FROM AUTHOR]

Abstract: The attack of novel avian influenza (H7N9) in East China caused a serious health crisis and public panic. In this paper, we empirically analyze the onset patterns of human cases of the novel avian influenza and observe several spatial and temporal properties that are similar to other infectious diseases. More specifically, using the empirical analysis and modeling studies, we find that the spatio-temporal network that connects the cities with human cases along the order of outbreak timing emerges two-regime-power-law edge-length distribution, indicating the picture that several islands with higher and heterogeneous risk straggle in East China. The proposed method is applicable to the analysis of the spreading situation in the early stage of disease outbreak using quite limited dataset. [Copyright &y& Elsevier]

Please cite this paper as: Pepin et al. (2012) Multiannual patterns of influenza A transmission in Chinese live bird market systems. Influenza and Other Respiratory Viruses DOI: 10.1111/j.1750-2659.2012.00354.x. Background Avian influenza viruses (AIV) cause huge economic losses in poultry industries and pose a substantial threat to human health. However, predicting AIV epizootics and emergence in humans is confounded by insufficient empirical data on the ecology and dynamics of AIV in poultry systems. To address this gap, we quantified incidence patterns for 13 hemagglutinin subtypes of AIV using 6 years of surveillance data that were collected from ten different species of poultry and three different types of poultry holdings (contexts) - retail, wholesale, or farms. Methods We collected 42 646 samples in Shantou, China between 2000 and 2006. We screened samples for hemagglutinin subtypes 1-13 of AIV and Avian Paramyxovirus-type-1 (APMV-1) using monospecific antisera in hemagglutination inhibition tests. We analyzed the data to determine seasonality patterns, subtype-host, and subtype-subtype interactions as well as subtype bias in incidence in different contexts. Results H3, H6, H9, and APMV-1 were the most prevalent. No significant seasonality was found when all subtypes were considered together. For most AIV subtypes and APMV-1, there was subtype specificity for host, context, and coinfection partner. H5 showed the most generalized host usage pattern, followed by H9 and H6. Conclusion Subtype-specific patterns because of host, context, and other subtypes suggest that risk assessments that exclude these details are likely inaccurate. Surveillance should include longitudinal sampling of multiple host species in multiple contexts. Quantitative models of control strategies must consider multiple subtypes, hosts, and source contexts to assess the effectiveness of interventions. [ABSTRACT FROM AUTHOR]

Abstract: Since 1997, when human infections with a highly pathogenic (HP) avian influenza A virus (AIV) subtype H5N1 – previously infecting only birds – were identified in a Hong Kong outbreak, global attention has focused on the potential for this virus to cause the next pandemic. From December 2003, an unprecedented H5N1 epizootic in poultry and migrating wild birds has spread across Asia and into Europe, the Middle East, and Africa. Humans in close contact with sick poultry and on rare occasion with other infected humans, have become infected. As of early March 2007, 12 countries have reported 167 deaths among 277 laboratory-confirmed human infections to WHO. WHO has declared the world to be in Phase 3 of a Pandemic Alert Period. This paper reviews the evolution of HP AIV H5N1, molecular changes that enable AIVs to infect and replicate in human cells and spread efficiently from person-to-person, and strategies to prevent the emergence of a pandemic virus. [Copyright &y& Elsevier]

In this paper, I examine chicken husbandry as practised in an immigrant village located in the north-western sector of Hong Kong's New Territories-the southern extension of the Pearl River Delta. People in South China use whole chickens as offerings in rituals and as banquet food. Demand for fresh, flavourful, whole chickens dominates the ways in which chickens are raised and sold in this region. Chicken farming is a highly competitive industry. The supply of birds from individual farms directly and immediately affects the market price, making neighbouring farms potential competitors with one another. On the other hand, diseases that kill the birds can easily spread from one farm to another, making the farmers inter-dependent in an environmental sense. It is the practice of poultry farmers not to visit their neighbours at home on the farm. Co-operation in respect to husbandry is minimal. This social structure effectively eliminates the spread of infectious diseases, but has contributed to the cellularization of households, fostering a loosely organized local community. The outbreak of avian flu, however, has created threats to and opportunities for chicken production, thus promoting co-operation and division of labour among chicken farmers. [ABSTRACT FROM AUTHOR]

This collection highlights some of the social, cultural, political and economic factors that must be considered in developing a biosocial approach to pandemic influenza control and prevention. To date, most discussions of the current spread of avian influenza and a predicted human influenza pandemic have lacked rigorous analysis of the local contexts in which flus arise and in which the effects of a pandemic would most strongly be felt. Such local engagement is necessary to the development of an effective and ethical programme of epidemic control. The papers in this special issue take a step towards filling this gap by exploring the local moral worlds associated with avian influenza in China, Indonesia and Thailand. [ABSTRACT FROM AUTHOR]

Based on ethnographic research conducted in the summer of 2006, this paper examines local responses to the imminent threat of avian flu in Haining County of Zhejiang Province. During our field investigation, we conducted interviews with officials from local medical institutions (including the hospitals, the animal husbandry and veterinary station, and health clinics), to bureaus of public health and agro-economy. We also visited chicken farms, restaurants and farming households. We address the following factors that commonly structured the perceptions and actions of different social actors in the area of study: The changing mode of information-sharing and communication practices in the local communities; the official drive to professionalize the emergency response management system in the county; and the coping mechanisms that helped the villagers and town residents to weather the storm of avian flu. Our field research suggests that collective survival consciousness was translated into a spirit of voluntarism during the crisis. One important practical lesson we have learned from this study is that the adaptive wisdom embedded in local memories demonstrated its operational worth as a resourceful knowledge base for ordinary farmers to deal with food shortage, famine, plague and future pandemics. [ABSTRACT FROM AUTHOR]

This paper provides an overview of the Hong Kong government's influenza preparedness plan and the key roles of public health nurses in that plan. The part played by Hong Kong public health nurses in the management of the avian influenza outbreak in Hong Kong in 1997 and the sudden acute respiratory syndrome outbreak in 2003, together with the capacity-building work they are now undertaking in preparing for an influenza pandemic, highlight their crucial role in public health. Recent strengthening of public health infrastructure in Hong Kong and heightened public awareness of public health issues have facilitated more proactive and effective public health nursing activities. [ABSTRACT FROM AUTHOR]

This article reports that global health experts trying to stave off a deadly pandemic of avian flu are alarmed by recent actions they see as counterproductive and even dangerous. Vietnam has been slow to report 10 new human cases, and farmers in China have reportedly been giving an antiviral drug to chickens that may have made the virus resistant to one of the few drugs available to fight human flu. Some bird flu experts are equally alarmed by China's veterinary use of the human antiviral drug amantadine, as reported in June 18, 2005 issue of the periodical "Washington Post." According to the paper, drug makers and other sources in China admitted that the drug has been sold cheaply to farmers and given to poultry both as a treatment and a prophylactic since the late 1990s. Most of the H5N1 strains isolated in the current outbreak in Asia are resistant to amantadine, but establishing a firm link with China's use of the drug would require extensive data on where, when, and how much of the drug was used. Still, given the threat of a pandemic and the dearth of flu drugs, the only alternative to amantadine and a cousin is oseltamivir, or Tamiflu, which is more expensive and harder to produce, antivirals should probably not be used for animal flu infection at all.

The article reports that the Chinese Ministry of Agriculture has allowed international scientists to analyze the samples of H5N1 avian influenza, collected from poultry during 2004 and 2005. In the first week of November 2006, the samples were sent to a U.S. laboratory, associated with the World Health Organization. Recently, a research paper published in the journal "Proceedings of the National Academy of Sciences," speculated about a new strain of H5N1. And China was being criticized for not cooperating with international health organizations.

This article reports that the Chinese Ministry of Agriculture sharply criticized a paper published online by the periodical "Nature," last week suggesting that an outbreak of H5N1 avian influenza among wild birds in northwest China originated from apparently unreported outbreaks among poultry in southern China. The researchers defend their results and worry that the ministry's reaction may lead to overly strict enforcement of new guidelines on handling the H5N1 virus. The brief report by Honglin Chen of Shantou University Medical College and colleagues there and at the University of Hong Kong and other institutions, posted on July 6, claims that the virus recovered from wild birds at Qinghai Lake is a genetic match to one found among poultry earlier this year at a live market in China's Guangdong Province. The following day, China's official Xinhua News Agency quoted Jia Youling, director general of the Agriculture Ministry's Veterinary Bureau, questioning the article's credibility because H5N1 has not been reported in Guangdong this year.