- Global spatial risk pattern of highly pathogenic avian influenza H5N1 virus in wild birds: A knowledge-fusion based approach. [Journal Article]
- PVPrev Vet Med 2018 Apr 01; 152:32-39
- Highly pathogenic avian influenza (HPAI) H5N1 viruses have continuously circulated throughout much of the world since 2003, resulting in huge economic losses and major public health problems. Wild bi...
Highly pathogenic avian influenza (HPAI) H5N1 viruses have continuously circulated throughout much of the world since 2003, resulting in huge economic losses and major public health problems. Wild birds have played an important role in the spread of H5N1 HPAI. To understand its spatial distribution, H5N1 HPAI have been studied by many disciplines from different perspectives, but only one kind of disciplinary knowledge was involved, which has provided limited progress in understanding. Combining risk information from different disciplines based on knowledge fusion can provide more accurate and detailed information. In this study, local k function, phylogenetic tree analysis, and logistic spatial autoregressive models were used to explore the global spatial pattern of H5N1 HPAI based on outbreak data in wild birds, genetic sequences, and risk factors, respectively. On this basis, Dempster-Shafer (D-S) evidence theory was further applied to study the spatial distribution of H5N1 HPAI. We found D-S evidence theory was more robust and reliable than the other three methods, providing technical and methodological support for application to the research of other diseases. The shortest distance to wild bird migration routes, roads and railways, elevation, the normalized difference vegetation index (NDVI), land use and land cover (LULC) and infant mortality rates (IMR) were significantly associated with the occurrence of H5N1 HPAI. The high-risk areas were mainly located in Northern and Central Europe, the eastern Mediterranean, and East and Southeast Asia. High-risk clusters were closely related to the social, economic and ecological environment of the region. Locations where the potential transmission risk remains high should be prioritized for control efforts.
- Changing Role of Wild Birds in the Epidemiology of Avian Influenza A Viruses. [Journal Article]
- AVAdv Virus Res 2018; 100:279-307
- Waterbirds are the main reservoir for low pathogenic avian influenza A viruses (LPAIV), from which occasional spillover to poultry occurs. When circulating among poultry, LPAIV may become highly path...
Waterbirds are the main reservoir for low pathogenic avian influenza A viruses (LPAIV), from which occasional spillover to poultry occurs. When circulating among poultry, LPAIV may become highly pathogenic avian influenza A viruses (HPAIV). In recent years, the epidemiology of HPAIV viruses has changed drastically. HPAIV H5N1 are currently endemic among poultry in a number of countries. In addition, global spread of HPAIV H5Nx viruses has resulted in major outbreaks among wild birds and poultry worldwide. Using data collected during these outbreaks, the role of migratory birds as a vector became increasingly clear. Here we provide an overview of current data about various aspects of the changing role of wild birds in the epidemiology of avian influenza A viruses.
- The Relative Contribution of Direct and Environmental Transmission Routes in Stochastic Avian Flu Epidemic Recurrence: An Approximate Analysis. [Journal Article]
- BMBull Math Biol 2018 Mar 14
- We present an analysis of an avian flu model that yields insight into the roles of different transmission routes in the recurrence of avian influenza epidemics. Recent modelling work suggests that th...
We present an analysis of an avian flu model that yields insight into the roles of different transmission routes in the recurrence of avian influenza epidemics. Recent modelling work suggests that the outbreak periodicity of the disease is mainly determined by the environmental transmission rate. This conclusion, however, is based on a modelling study that only considers a weak between-host transmission rate. We develop an approximate model for stochastic avian flu epidemics, which allows us to determine the relative contribution of environmental and direct transmission routes to the periodicity and intensity of outbreaks over the full range of plausible parameter values for transmission. Our approximate model reveals that epidemic recurrence is chiefly governed by the product of a rotation and a slowly varying standard Ornstein-Uhlenbeck process (i.e. mean-reverting process). The intrinsic frequency of the damped deterministic version of the system predicts the dominant period of outbreaks. We show that the typical periodicity of major avian flu outbreaks can be explained in terms of either or both types of transmission and that the typical amplitude of epidemics is highly sensitive to the direct transmission rate.
- Co-circulation of multiple genotypes of influenza A (H7N9) viruses in eastern China, 2016-2017. [Journal Article]
- AVArch Virol 2018 Mar 14
- Five epidemic waves of human infection with influenza A (H7N9) virus have emerged in China since spring 2013. We previously described the epidemiological characterization of the fifth wave in Jiangsu...
Five epidemic waves of human infection with influenza A (H7N9) virus have emerged in China since spring 2013. We previously described the epidemiological characterization of the fifth wave in Jiangsu province. In this study, 41 H7N9 viruses from patients and live-poultry markets were isolated and sequenced to further elucidate the genetic features of viruses of the fifth wave in Jiangsu province. Phylogenetic analysis revealed substantial genetic diversity in the internal genes, and 18 genotypes were identified from the 41 H7N9 virus strains. Furthermore, our data revealed that 41 isolates from Jiangsu contained the G186V and Q226L/I mutations in their haemagglutinin (HA) protein, which may increase the ability of these viruses to bind the human receptor. Four basic amino acid insertions were not observed in the HA cleavage sites of 167 H7N9 viruses from Jiangsu, which revealed that highly pathogenic avian influenza (HPAI) H7N9 viruses did not spread to Jiangsu province in the fifth wave. These findings revealed that multiple genotypes of H7N9 viruses co-circulated in the fifth wave in Jiangsu province, which indicated that the viruses have undergone ongoing evolution with genetic mutation and reassortment. Our study highlights the need to constantly monitor the evolution of H7N9 viruses and reinforce systematic influenza surveillance of humans, birds, and pigs in China.
- Emergence and spread of highly pathogenic avian influenza A(H5N8) in Europe in 2016-2017. [Journal Article]
- TETransbound Emerg Dis 2018 Mar 14
- Circulation of highly pathogenic avian influenza (HPAI) viruses poses a continuous threat to animal and public health. After the 2005-2006 H5N1 and the 2014-2015 H5N8 epidemics, another H5N8 is curre...
Circulation of highly pathogenic avian influenza (HPAI) viruses poses a continuous threat to animal and public health. After the 2005-2006 H5N1 and the 2014-2015 H5N8 epidemics, another H5N8 is currently affecting Europe. Up to August 2017, 1,112 outbreaks in domestic and 955 in wild birds in 30 European countries have been reported, the largest epidemic by a HPAI virus in the continent. Here, the main epidemiological findings are described. While some similarities with previous HPAI virus epidemics were observed, for example in the pattern of emergence, significant differences were also patent, in particular the size and extent of the epidemic. Even though no human infections have been reported to date, the fact that A/H5N8 has affected so far 1,112 domestic holdings, increases the risk of exposure of humans and therefore represents a concern. Understanding the epidemiology of HPAI viruses is essential for the planning future surveillance and control activities.
- Emergence of novel reassortant H6N2 avian influenza viruses in ducks in India. [Journal Article]
- IGInfect Genet Evol 2018 Mar 09; 61:20-23
- The recent reports of human infection due to H6 subtype avian influenza viruses (AIV), which are prevalent in terrestrial poultry, indicate evolution of the virus to a possible pandemic strain. Here,...
The recent reports of human infection due to H6 subtype avian influenza viruses (AIV), which are prevalent in terrestrial poultry, indicate evolution of the virus to a possible pandemic strain. Here, we report antigenic and genetic characterization of two H6N2 viruses isolated from apparently healthy domestic ducks in Kerala and Assam, India during 2014 and 2015, respectively. Hemagglutination inhibition assay revealed antigenic divergence between the two isolates, which was corroborated by amino acid differences at 55 positions (15.98%) between their hemagglutinin (HA) 1.The sequence analyses indicated that both the viruses are avian origin with avian receptor specificity, low pathogenic to poultry and sensitive to oseltamivir. However, Kerala14 had V27I mutation marker for amantadine resistance in M2. The Assam15 virus had an additional N-linked glycosylation on HA2 (position 557) compared to Kerala14 virus. Phylogenetic analysis of the HA gene revealed that both the viruses belonged to distinct lineages (Eurasian and Asia II). Phylogeny of neuraminidase and internal gene segments revealed that both the viruses are novel reassortants and are genetically distinct with different gene constellations. The results suggest independent introductions of the two H6N2 viruses into India and migratory wild birds in the Central Asian flyway might be the source of H6N2 viruses in ducks in India. Therefore, continued AIV surveillance in poultry and wild birds is essential for early detection of emergence of novel strains with pandemic potential and control of their spread.
- Influence of Novel Highly Pathogenic Avian Influenza A (H5N1) Virus Infection on Migrating Whooper Swans Fecal Microbiota. [Journal Article]
- FCFront Cell Infect Microbiol 2018; 8:46
- The migration of wild birds plays an important role in the transmission and spread of H5 highly pathogenic avian influenza (HPAI) virus, posing a severe risk to animal and human health. Substantial e...
The migration of wild birds plays an important role in the transmission and spread of H5 highly pathogenic avian influenza (HPAI) virus, posing a severe risk to animal and human health. Substantial evidence suggests that altered gut microbial community is implicated in the infection of respiratory influenza virus. However, the influence of H5N1 infection in gut microbiota of migratory birds remains unknown. In January 2015, a novel recombinant H5N1 virus emerged and killed about 100 migratory birds, mainly including whooper swans in Sanmenxia Reservoir Area of China. Here, we describe the first fecal microbiome diversity study of H5N1-infected migratory birds. By investigating the influence of H5N1 infection on fecal bacterial communities in infected and uninfected individuals, we found that H5N1 infection shaped the gut microbiota composition by a difference in the dominance of some genera, such asAeromonasandLactobacillus. We also found a decreased α diversity and increased β diversity in infectious individuals. Our results highlight that increases in changes in pathogen-containing gut communities occur when individuals become infected with H5N1. Our study may provide the first evidence that there are statistical association among H5N1 presence and fecal microbiota compositional shifts, and properties of the fecal microbiota may serve as the risk of gut-linked disease in migrates with H5N1 and further aggravate the disease transmission.
- Co-infection of turkeys with E. coli (O78) and H6N1 avian influenza virus. [Journal Article]
- APAvian Pathol 2018 Mar 08; :1-39
- Respiratory diseases are responsible for major economic losses in poultry farms. While in most cases a single pathogen is not alone responsible for the clinical outcome, the impact of co-infections i...
Respiratory diseases are responsible for major economic losses in poultry farms. While in most cases a single pathogen is not alone responsible for the clinical outcome, the impact of co-infections is not well known, especially in turkeys. The purpose of this study was to assess the possible synergism between E.coli (O78) and low pathogenic avian influenza virus (LPAIV, H6N1), in the turkey model. Four-week-old commercial turkeys were inoculated with either H6N1, O78 or both agents simultaneously or 3 days apart. We have established an experimental infection model of turkeys using aerosolization that better mimics field infections. Birds were observed clinically and swabbed on a daily basis. Necropsies were performed at 4 and 14 days post single or dual inoculation and followed by histological and immunohistochemical analyses. Combined LPAIV/E.coli infections resulted in more severe clinical signs, were associated with higher mortality and respiratory organ lesions (mucous or fibrinous exudative material in lungs and airsacs), in comparison with the groups given single infections (p<0.05). The time interval or the sequence between H6N1 and E. coli inoculation (none or 3 days) did not have a significant effect on the outcome of the dual infection and disease although slightly higher (p>0.05) respiratory signs were observed in turkeys of the E.coli followed by H6N1 inoculated group. Microscopic lesions and immunohistochemical staining supported clinical and macroscopic findings. Efficient virus and bacteria replication was observed in all inoculated groups. E. coli and H6N1 thus exercise an additive or synergistic pathogenic effect in the reproduction of respiratory disease.
- Assessing the probability of introduction and spread of avian influenza (AI) virus in commercial Australian poultry operations using an expert opinion elicitation. [Journal Article]
- PlosPLoS One 2018; 13(3):e0193730
- The objective of this study was to elicit experts' opinions and gather estimates on the perceived probability of introduction and spread of avian influenza (AI) virus in the Australian broiler and la...
The objective of this study was to elicit experts' opinions and gather estimates on the perceived probability of introduction and spread of avian influenza (AI) virus in the Australian broiler and layer industry. Using a modified Delphi method and a 4-step elicitation process, 11 experts were asked to give initial individual estimates for the various pathways and practices in the presented scenarios using a questionnaire. Following this, a workshop was conducted to present group averages of estimates and discussion was facilitated to obtain final individual estimates. For each question, estimates for all experts were combined using a discrete distribution, with weights allocated representing the level of expertise. Indirect contact with wild birds either via a contaminated water source or fomites was considered the most likely pathway of introduction of low pathogenic avian influenza (LPAI) on poultry farms. Presence of a water body near the poultry farm was considered a potential pathway for introduction only when the operation type was free range and the water body was within 500m distance from the shed. The probability that LPAI will mutate to highly pathogenic avian influenza (HPAI) was considered to be higher in layer farms. Shared personnel, equipment and aerosol dispersion were the most likely pathways of shed to shed spread of the virus. For LPAI and HPAI spread from farm to farm, shared pick-up trucks for broiler and shared egg trays and egg pallets for layer farms were considered the most likely pathways. Findings from this study provide an insight on most influential practices on the introduction and spread of AI virus among commercial poultry farms in Australia, as elicited from opinions of experts. These findings will be used to support parameterization of a modelling study assessing the risk of AI introduction and spread among commercial poultry farms in Australia.
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- Meat in the post-truth era: Mass media discourses on health and disease in the attention economy. [Journal Article]
- AAppetite 2018 Feb 24; 125:345-355
- The debate on meat's role in health and disease is a rowdy and dissonant one. This study uses the health section of the online version of The Daily Mail as a case study to carry out a quantitative an...
The debate on meat's role in health and disease is a rowdy and dissonant one. This study uses the health section of the online version of The Daily Mail as a case study to carry out a quantitative and qualitative reflection on the related discourses in mass media during the first fifteen years of the 21st century. This period ranged from the fall-out of the bovine spongiform encephalopathy (BSE) crisis and its associated food safety anxieties, over the Atkins diet-craze in 2003 and the avian flu episode in 2007, to the highly influential publication of the report on colon cancer by the International Agency for Research on Cancer (IARC) in 2015. A variety of conflicting news items was discernible, whereby moments of crisis, depicting the potential hazards of meat eating, seemed to generate reassuring counter-reactions stressing the benefits of meat as a rich source of nutrients. In contrast, when the popularity of meat-rich diets was on the rise due to diets stressing the role of protein in weight control, several warnings were issued. Meat's long-standing and semiotic connotations of vitality, strength, and fertility were either confirmed, rejected or inverted. Often this was achieved through scientification or medicalisation, with references to nutritional studies. The holistic role of meat within human diets and health was thus mostly reduced to a focus on specific food components and isolated biological mechanisms. The narratives were often histrionic and displayed serious contradictions. Since several interests were at play, involving a variety of input from dieticians, (health) authorities, the food industry, vegan or vegetarian movements, and celebrities, the overall discourse was highly heterogeneous.