Spatial transmission of avian influenza (type H5) in birds

Highly pathogenic avian influenza (HPAI) H5N1 continues to threaten domestic and wild birds, as well as human health. However, the mechanism of spatial transmission of HPAI is still unclear. We analyzed the current distribution of HPAI occurrences based on World Organization for Animal Health reported data from 3049 sites in the world from December 2003 to June 2006, and found that these sites were spaced at distances with a frequency peak of 100–200 km. We built a cellular automata model to simulate the spatial transmission process of HPAI as a function of transmission distance, variance of the transmission distance, infection rate, and transmission times (how many times HPAI transmits from one host to another before suppression). We determined that the transmission distance between HPAI occurrences is approximately 100 km on the basis of historical HPAI occurrences from 2003 to 2006 in both wild and domestic birds. To effectively reduce the long‐distance spreading of HPAI, preventing close contact between domestic birds and waterfowl within a radius of 100 km around HPAI occurrence sites is essential.     

The Perceived Value of Passive Animal Health Surveillance: The Case of Highly Pathogenic Avian Influenza in Vietnam

Economic evaluations are critical for the assessment of the efficiency and sustainability of animal health surveillance systems and the improvement of their efficiency. Methods identifying and quantifying costs and benefits incurred by public and private actors of passive surveillance systems (i.e. actors of veterinary authorities and private actors who may report clinical signs) are needed. This study presents the evaluation of perceived costs and benefits of highly pathogenic avian influenza (HPAI) passive surveillance in Vietnam. Surveys based on participatory epidemiology methods were conducted in three provinces in Vietnam to collect data on costs and benefits resulting from the reporting of HPAI suspicions to veterinary authorities. A quantitative tool based on stated preference methods and participatory techniques was developed and applied to assess the non‐monetary costs and benefits. The study showed that poultry farmers are facing several options regarding the management of HPAI suspicions, besides reporting the following: treatment, sale or destruction of animals. The option of reporting was associated with uncertain outcome and transaction costs. Besides, actors anticipated the release of health information to cause a drop of markets prices. This cost was relevant at all levels, including farmers, veterinary authorities and private actors of the upstream sector (feed, chicks and medicine supply). One benefit associated with passive surveillance was the intervention of public services to clean farms and the environment to limit the disease spread. Private actors of the poultry sector valued information on HPAI suspicions (perceived as a non‐monetary benefit) which was mainly obtained from other private actors and media.     

我国乳业安全激励性规制政策演化广度分析

近年来我国奶类产量持续稳定增长,我国作为一个乳制品生产大国,乳业已经形成了一个系统的产业链,从饲草种植、奶畜养殖等产业链上游环节到乳制品生产与加工、销售配送等产业下游各个环节。为了保障乳业安全,我国政府出台了大量的强制性规制政策和很多促进乳业健康发展的激励性规制政策,以实现乳业安全的协同治理。2006年7月出台的《中华人民共和国畜牧法》首次明确提出,鼓励和扶持发展规模化养殖以及支持畜牧业进行良种补贴、贴息补助等具体措施。2021年农业农村部出台重点强农惠农政策,推进奶业振兴。本文在梳理2006—2021年我国乳业政府激励性规制政策的基础上,构建了CTAP政策分析框架,基于时间视角从政策内容（C）、政策类型（T）、政策发文主体（A）与政策力度（P）四个方面对我国乳业安全政府激励性规制政策的演化广度进行分析,明晰我国乳业激励性规制政策演化特征及其未来发展趋势。     

Infectious dose‐dependent accumulation of live highly pathogenic avian influenza H5N1 virus in chicken skeletal muscle—implications for public health

Highly pathogenic avian influenza viruses (HPAIV) of H5N1 subtype are a major global threat to poultry and public health. Export of poultry products, such as chicken and duck meat, is a known source for the cross‐boundary spread of HPAI H5N1 viruses. Humans get infected with HPAI H5N1 viruses either by close contact with infected poultry or through consumption of fresh/undercooked poultry meat. Skeletal muscle is the largest soft tissue in chicken that has been shown to contain virus during systemic HPAIV infection and supports productive virus infection. However, the time between infection of a chicken with H5N1 virus and presence of virus in muscle tissue is not yet known. Further, it is also not clear whether chicken infected with low doses of H5N1 virus that cause non‐fatal subclinical infections continue to accumulate virus in skeletal muscle. We investigated the amount and duration of virus detection in skeletal muscle of chicken experimentally infected with different doses (10², 10³ and 10⁴ EID₅₀) of a HPAI H5N1 virus. Influenza viral antigen could be detected as early as 6 hr after infection and live virus was recovered from 48 hr after infection. Notably, chicken infected with lower levels of HPAI H5N1 virus (i.e., 10² EID₅₀) did not die acutely, but continued to accumulate high levels of H5N1 virus in skeletal muscle until 6 days post‐infection. Our data suggest that there is a potential risk of human exposure to H5N1 virus through meat from clinically healthy chicken infected with a low dose of virus. Our results highlight the need to implement rigorous monitoring systems to screen poultry meat from H5N1 endemic countries to limit the global spread of H5N1 viruses.     

A Systematic Scoping Study of the Socio‐Economic Impact of Rift Valley Fever: Research Gaps and Needs

Rift Valley fever (RVF) is a severe mosquito‐borne disease affecting humans and domestic ruminants. RVF virus has been reported in most African countries, as well as in the Arabic Peninsula. This paper reviews the different types of socio‐economic impact induced by RVF disease and the attempts to evaluate them. Of the 52 papers selected for this review, 13 types of socio‐economic impact were identified according to the sector impacted, the level and temporal scale of the impact. RVF has a dramatic impact on producers and livestock industries, affecting public and animal health, food security and the livelihood of the pastoralist communities. RVF also has an impact on international trade and other agro‐industries. The risk of introducing RVF into disease‐free countries via the importation of an infected animal or mosquito is real, and the consequent restriction of access to export markets may induce dramatic economic consequences for national and local economies. Despite the important threat of RVF, few studies have been conducted to assess the socio‐economic impact of the disease. The 17 studies identified for quantitative analysis in this review relied only on partial cost analysis, with limited reference to mid‐ and long‐term impact, public health or risk mitigation measures. However, the estimated impacts were high (ranging from $5 to $470 million USD losses). To reduce the impact of RVF, early detection and rapid response should be implemented. Comprehensive disease impact studies are required to provide decision‐makers with science‐based information on the best intervention measure to implement ensuring efficient resource allocation. Through the analysis of RVF socio‐economic impact, this scoping study proposes insights into the mechanisms underpinning its often‐underestimated importance. This study highlights the need for comparative socio‐economic studies to help decision‐makers with their choices related to RVF disease management.     

Integrated surveillance of antimicrobial resistance and antimicrobial use: Evaluation of the status in Canada (2014–2019)

Objective Integrated surveillance of antimicrobial resistance (AMR) and antimicrobial use (AMU) across One Health sectors is critically important for effective, evidence-based policy, stewardship, and control of AMR. Our objective was to evaluate progress towards achieving comprehensive, integrated AMR/AMU surveillance in Canada.Materials and methods Based on an environmental scan, interviews of subject matter experts, and reports from the 2014 National Collaborating Centre for Infectious Diseases and the 2016 Canadian Council of Chief Veterinary Officers, we identified 8 core surveillance requirements and their specific components; the latter were assessed using a 2-way classification matrix, with 7 common elements ranked according to development stage.Results Components that mapped to requirements of a comprehensive, fully integrated AMR/AMU surveillance system were mostly in the lowest stages of development (Exploration or Program Adoption). However, both the establishment of the Canadian AMR Surveillance System integrated reporting and expansion of existing components under the Canadian Nosocomial Infection Surveillance Program and the Canadian Integrated Program for AMR Surveillance are improvements. Regardless, obvious gaps in Canadian AMR/AMU surveillance prevent this from being a comprehensive and integrated One Health program.Conclusion Action is needed in 3 crucial areas: i) development of a complete, integrated AMR/AMU surveillance program, based on current success; ii) changes in Federal/Provincial/Territorial policies to require standardized AMR/AMU reporting; and iii) more resources for AMR/AMU surveillance (dedicated persons, funding, and enabling structures and policy). There is an urgent need for prioritization by Federal/Provincial/Territorial governments to address governance, leadership, and funding to create surveillance systems that inform stewardship and policy.     

Control versus no control: options for avian influenza H5N1 in Nigeria

In January 2006, an outbreak of a highly pathogenic avian influenza (HPAI) was recorded in Nigeria for the first time. This present work describes an estimation of possible costs associated with a vaccination-based control policy added to other measures to restrict HPAI H5N1 virus infections. The evaluations used epidemiological and production data, including budgets necessary for the vaccine acquisition, distribution and administration in arriving at the final costs. Using decision tree and cost benefit analysis the economical benefits for Nigeria and countries with similar veterinary infrastructures, biosecurity and farming systems are calculated. The result indicated that a halting in the continued spread of the virus through effective control measure will be 52 times better than taking no action. This should help policy makers in deciding in favour of vaccination combined with other tools as an effective means of controlling avian influenza H5N1. * Control of HPAI H5N1 will best be understood by policy makers in financial terms. * Effective control through vaccination of poultry is much cheaper and reduces the chances of human zoonoses. * Poultry vaccination combined with other control measures will be the most effective means of control in most developing economies.     

A qualitative assessment of disease surveillance activities in a resource‐limited environment: Perceptions and opinions of volunteer staff working in Northern Uganda

Annually, groups of health professionals from high‐income countries are drawn to work in low‐ and middle‐income countries (LMICs) through timed engagements intended to improve the well‐being of people in most disadvantaged communities. The existing evidence on understanding volunteer experience in LMICs often focuses on activities within the medical discipline; whereas little research has been conducted on the experiences of volunteers in other disciplines. This paper focuses on understanding veterinary and public health professional's experiences conducting disease surveillance work in Northern Uganda. Forty US‐based health care professionals were recruited to complete multiple‐choice and open‐ended questions to understand prior and current experiences working in resource‐limited settings. Responses were coded using NVivo 10®, qualitative analysis package. Of the 44 volunteers, 50% completed the questionnaire. Responses were largely positive towards surveillance activities; they reported personal and professional gains, new cultural experiences and mutual learning environment with local colleagues. Nevertheless, respondents highlighted challenges during various stages of program implementation—some difficulty with program logistics, inadequacy of preparation materials, in addition to concerns inherent to working in a resource‐limited environment. This assessment suggests that international volunteer work could positively influence programmatic outcomes, personal experiences, furthering health organizational goals, often achieved in a limited time‐frame. To maximize volunteer impact, these assessments are critical and suggest that volunteer and institutional capacities should be seriously considered when planning placement as it can influence programmatic decision‐making, gauge training needs and volunteer readiness.     

Qualitative risk assessment of transmission pathways of highly pathogenic avian influenza (HPAI) virus at live poultry markets in Dhaka city,Bangladesh

Analysis of environmental samples obtained from the Live Poultry Markets (LPMs) of Dhaka City, Bangladesh, has revealed that the highest degree of prevalence of highly pathogenic avian influenza A (HPAI, H5N1), besides other subtypes of the LPAI virus, poses the plausible risk of transmission of these viruses between human and poultry species. The present study was conducted using the OIE risk analysis framework to assess the risk level of each pathway successively. The estimated risk parameters were integrated towards to obtain the overall risk level for each specific HPAI transmission pathway using the matrix adapted by Cristobel Zepeda accompanying other expert consultations. The relevant data obtained from published and unpublished sources, together with survey data of field observations, were used to formulate and confirm the risk pathways and their associated risks. The results revealed that the risk of the release of the HPAI virus was medium when exposure was high. Additionally, the consequence would be considered very high with a medium degree of uncertainty for all parameters. Ultimately, the overall risk for transmission was estimated as medium with a medium degree of uncertainty. The findings of this study reveal that there is a significant threat that HPAI virus transmission could occur among poultry and humans and effectively sustain within the environment of the LPMs. Our findings are primarily focused on public health considerations, the hygienic slaughter of poultry and the relevant cleaning and sanitation practices conducted in the LPMs to support evidence‐based decision‐making processes. The findings of the study have the potential to be used to formulate effective risk reduction measures and can be further adapted in low‐resource settings without major infrastructural changes required of the LPMs. All of which would reduce the risk of HPAI virus release and further lessen the degree of exposure and transmission in established LPMs.     

Effect of species,breed and route of virus inoculation on the pathogenicity of H5N1 highly pathogenic influenza (HPAI) viruses in domestic ducks

H5N1 highly pathogenic avian influenza (HPAI) viruses continue to be a threat to poultry in many regions of the world. Domestic ducks have been recognized as one of the primary factors in the spread of H5N1 HPAI. In this study we examined the pathogenicity of H5N1 HPAI viruses in different species and breeds of domestic ducks and the effect of route of virus inoculation on the outcome of infection. We determined that the pathogenicity of H5N1 HPAI viruses varies between the two common farmed duck species, with Muscovy ducks (Cairina moschata) presenting more severe disease than various breeds of Anas platyrhynchos var. domestica ducks including Pekin, Mallard-type, Black Runners, Rouen, and Khaki Campbell ducks. We also found that Pekin and Muscovy ducks inoculated with two H5N1 HPAI viruses of different virulence, given by any one of three routes (intranasal, intracloacal, or intraocular), became infected with the viruses. Regardless of the route of inoculation, the outcome of infection was similar for each species but depended on the virulence of the virus used. Muscovy ducks showed more severe clinical signs and higher mortality than the Pekin ducks. In conclusion, domestic ducks are susceptible to H5N1 HPAI virus infection by different routes of exposure, but the presentation of the disease varied by virus strain and duck species. This information helps support the planning and implementation of H5N1 HPAI surveillance and control measures in countries with large domestic duck populations.     

Accessible and inexpensive tools for global HPAI surveillance: A mobile-phone based system

Highly pathogenic avian influenza (HPAI) disproportionately impacts poor livestock keepers in southern countries. Although the estimated cost of the disease in the billions, response to the epidemic remains fragmented and information channels slow. Given the continuing threat of outbreaks, and what appears to be the politicisation of outbreak reporting, new tools are needed to enforce transparency in stakeholder communication. In response to this need, we created a mobile-phone based surveillance system to aid critical information transfer among policy makers, practitioners and the poor themselves. The tool operates at the local, national and global levels and further links decision-makers to international databases.     

Preventing highly pathogenic avian influenza (HPAI) at the rural community level: a case study from Cambodia

Poultry is an integral part of the rural livelihoods in Cambodia, with more than half of the households keeping poultry in their small-scale, traditional, and extensive backyards. More than 20 highly pathogenic avian influenza (HPAI) outbreaks have been reported since 2004 with deaths of over 21,000 birds. During the HPAI outbreaks, some of the flocks in the rural areas were culled without compensation and producers were not allowed to sell outside of the community. Heifer International worked with 2,000 rural families through local project partners in the target communities to develop an effective intervention mechanism to mitigate the impact of the HPAI crisis. Heifer International provided training, public education, and networking as well as promoting model farms based on improved scavenging poultry management. Each community selected one farm family to serve as a model farm. They were trained in Heifer's working approach and committed to practicing integrated farming systems based on scavenging poultry management. One Village Animal Health Worker (VAHW) in each community participated during the project implementation, playing a key role in the information exchange and the interaction between the communities and the avian influenza experts. Formal and informal trainings were conducted for all project partners and project recipients through experts and VAHWs, respectively. There have been no outbreaks reported in the communities in the project areas. Farmers have started using appropriate techniques to maintain biosecurity. They are passing on the knowledge and the skills to the surrounding communities. This participatory approach in educating rural farmers can serve as a model to mitigate HPAI in the developing countries around the world.     

Farmer’s views and values to focus on cattle conservation policies: the case of eight European countries

Our aim was to identify elements useful in designing policies and programmes for conservation of farm animal genetic resources, taking as case study a group of European local cattle breeds. We first investigated the implications of differences among countries in the policies and programmes to be developed. Secondly, we analysed key elements common to countries, which may affect local breed viability. We used the herd size trend expected by the farmer in the near future as an indicator of breed viability. Fifteen breeds, for a total of 355 farms, were surveyed. To take into account the multiple factors influencing breeds’ demographic trends, the questionnaire included economical, technical and social aspects. Among the major differences across countries was the perception of the farmer on the value attributed to the local breed by society. Concerning the elements common to countries and their association to breed viability, the greater the collaboration among farmers and the stakeholders’ appreciation as perceived by the farmer, the greater the viability of the farm. An opposite trend was observed for the age of the farmer. Older farmers generally planned to soon cease farming or decrease herd size, whereas young farmers planned to increase the size of their herds. Implications of including these elements in conservation polices are discussed.     

A Survey of Canadian Public Health Personnel Regarding Knowledge,Practice and Education of Zoonotic Diseases

Zoonoses, diseases that can spread under natural conditions between humans and other animals, are become a major public health concern in many countries including Canada. In Canada, investigations of zoonotic disease incidents are often conducted by public health inspectors (PHIs). However, little is known about PHIs' knowledge of transmission of zoonotic pathogens, their perceptions of zoonotic disease importance or their education regarding zoonotic diseases. The objective of this study was therefore to assess the knowledge, perceptions and education of Canadian PHIs regarding zoonotic diseases. Data were collected from December 2008–January 2009 using an internet‐based survey distributed to members of the Canadian Institute of Public Health Inspectors national listserv. Responses were received from 229 PHIs in four provinces, with a response rate of approximately 20%. The majority of respondents reported at least 10 years of experience in the public health sector, 80% (181/225) were in frontline positions, and 62% (137/222) were routinely involved in investigations of infectious diseases. Two‐thirds believed that the importance of zoonotic diseases with regards to public health would increase in the next 5 years. Whilst most respondents were able to correctly identify animals capable of directly transmitting common zoonotic pathogens, there were gaps in knowledge, particularly with regard to rabies and transmission of gastrointestinal pathogens by companion animals. PHIs tended to feel that their training on zoonotic diseases prior to working as PHIs was deficient in some areas, or left some room for improvement. Their responses also suggested that there is a need for improvement in both the quantity and the quality of continuing education on zoonotic diseases. In particular, less than one‐third of PHIs received ongoing continuing education regarding zoonotic diseases, and of those that did, nearly two‐thirds rated the quantity and quality as only fair.     

Avian Influenza A(H5N1) Virus Outbreak Investigation: Application of the FAO‐OIE‐WHO Four‐way Linking Framework in Indonesia

WHO, FAO and OIE developed a ‘four‐way linking’ framework to enhance the cross‐sectoral sharing of epidemiological and virological information in responding to zoonotic disease outbreaks. In Indonesia, outbreak response challenges include completeness of data shared between human and animal health authorities. The four‐way linking framework (human health laboratory/epidemiology and animal health laboratory/epidemiology) was applied in the investigation of the 193rd human case of avian influenza A(H5N1) virus infection. As recommended by the framework, outbreak investigation and risk assessment findings were shared. On 18 June 2013, a hospital in West Java Province reported a suspect H5N1 case in a 2‐year‐old male. The case was laboratory‐confirmed that evening, and the information was immediately shared with the Ministry of Agriculture. The human health epidemiology/laboratory team investigated the outbreak and conducted an initial risk assessment on 19 June. The likelihood of secondary cases was deemed low as none of the case contacts were sick. By 3 July, no secondary cases associated with the outbreak were identified. The animal health epidemiology/laboratory investigation was conducted on 19–25 June and found that a live bird market visited by the case was positive for H5N1 virus. Once both human and market virus isolates were sequenced, a second risk assessment was conducted jointly by the human health and animal health epidemiology/laboratory teams. This assessment concluded that the likelihood of additional human cases associated with this outbreak was low but that future sporadic human infections could not be ruled out because of challenges in controlling H5N1 virus contamination in markets. Findings from the outbreak investigation and risk assessments were shared with stakeholders at both Ministries. The four‐way linking framework clarified the type of data to be shared. Both human health and animal health teams made ample data available, and there was cooperation to achieve risk assessment objectives.     

Legislation for the control of avian influenza in the European union

In the light of experience gained with avian influenza (AI) outbreaks in Europe and elsewhere in the world, the European Union (EU) legislation has recently been updated. The strategy to control the introduction and spread of AI relies on rapid disease detection, killing of infected birds, movement restrictions for live birds and their products, cleaning and disinfection and vaccination. Measures are not only to be implemented in case of outbreaks of highly pathogenic AI (HPAI), but are now also directed against occurrence of low pathogenic AI of H5 and H7 (LPAI) subtypes in poultry, albeit in a modified manner proportionate to the risk posed by these pathotypes. Enhanced surveillance in poultry holdings and wild birds, as well as preventive vaccination, has also been introduced. EU Measures are flexible and largely based on risk assessment of the local epidemiological situation. The occurrence of HPAI H5N1 of the Asian lineage in the EU and its unprecedented spread by wild migratory birds necessitated the adoption of additional control measures. Although HPAI H5N1 has affected wild birds and poultry holdings in several EU Member States, EU legislation and its implementation in Member States has so far successfully limited the impact of the disease on animal and human health.     

Virus Spread Pattern within Infected Chicken Farms using Regression Model: the 2003–2004 HPAI Epidemic in the Republic of Korea

During the 2003–2004 epidemic in Korea, the infection time and within‐farm spread pattern of virus were analysed for the highly pathogenic avian influenza (HPAI) outbreak on chicken farms using regression models based on epidemiological data. Mortality observed on a given day had a positive linear association with time after initial infection. HPAI spread more rapidly on farms managed by employees and on farms with larger numbers of chicken houses in use. The disease spread more rapidly among layer chickens than among broilers. Using statistical model, we found that farmers recognize the abnormally high mortality resulting from HPAI approximately 5 days after infection. Without any intervention, entire flocks would die within 12 days of introduction of the HPAI virus to the infected farm.     

An Outbreak of Highly Pathogenic Avian Influenza at a Public Animal Exhibit in Seoul,Korea, During 2008

This study describes the first recorded outbreak of HPAI in the city of Seoul, in captive birds held in an exhibition for public viewing at a local district office. The index cases were two pheasants, which had been introduced into the exhibit on 24 April, 4 days prior to death, from a store in a local market in Gyeonggi‐do. Ducks and chickens from an HPAI outbreak farm, subsequently confirmed on 4 May, had also been held in this store. This outbreak highlights the potential role of local markets in AIV transmission. This outbreak led to considerable public health concern in Korea, however, no human cases were reported. The non‐commercial poultry sector needs to be considered in national plans for preparedness and response.