Influenza in birds is caused by infection with viruses of the family Orthomyxoviridae placed in the genus influenzavirus A. Influenza A viruses are the only orthomyxoviruses known to naturally affect birds. Many species of birds have been shown to be susceptible to infection with influenza A viruses; aquatic birds form a major reservoir of these viruses, and the overwhelming majority of isolates have been of low pathogenicity (low virulence) for chickens and turkeys. Influenza A viruses have antigenically related nucleocapsid and matrix proteins, but are classified into subtypes on the basis of their haemagglutinin (H) and neuraminidase (N) antigens (World Health Organization Expert Committee, 1980). At present, 16 H subtypes (H1–H16) and 9 N subtypes (N1–N9) are recognised with proposed new subtypes (H17, H18) for influenza A viruses from bats in Guatemala (Swayne et al., 2013; Tong et al., 2012; 2013). To date, naturally occurring highly pathogenic influenza A viruses that produce acute clinical disease in chickens, turkeys and other birds of economic importance have been associated only with the H5 and H7 subtypes. Most viruses of the H5 and H7 subtype isolated from birds have been of low pathogenicity for poultry. As there is the risk of a H5 or H7 virus of low pathogenicity (H5/H7 low pathogenicity avian influenza [LPAI]) becoming highly pathogenic by mutation, all H5/H7 LPAI viruses from poultry are notifiable to OIE. In addition, all high pathogenicity viruses from poultry and other birds, including wild birds, are notifiable to the OIE.
In January 2012, the OIE gave in Japan an update on the latest developments in killing animals for disease control purposes. The Anoxia method was one of the presented techniques. Today, one year later, the Anoxia technique is commercially available worldwide. Inhumane killing of animals is not longer necessary and the risks of getting infected has been reduced to a minimum.
Pig Progress Dec 2, 2013. South Korea’s first outbreak of Classical Swine Fever (CSF) in four years has led to the culling of a herd of 300 pigs, reports the Organization of Animal Health (OIE). The previous outbreak dated from April 2009, the OIE states. This time the outbreak was confirmed at a rearing farm in Siran-dong, in the province Gyeongsangnam-do, on the south coast of the Korean peninsula. The infection was discovered on November 27 – one day later the OIE was informed. In total, four out of 300 pigs were found infected and as a result, all pigs were destroyed.The location of the outbreak can be seen on the interactive map included in the OIE report.
International experts recommend vigilance and promote targeted surveillance, market restructuring to fight H7N9, H5N1 and other threats. 16 September 2013, Rome – FAO has issued a new warning to the international community that the H7N9 and H5N1 avian influenza viruses continue to pose serious threats to human and animal health, especially in view of the upcoming flu season.
“The world is more prepared than ever before to respond to bird flu viruses in light of a decade of work on H5N1 and the recent response to H7N9,” said FAO Chief Veterinary Officer Juan Lubroth at a joint meeting with United States Agency for International Development (USAID), the World Health Organization (WHO) and the World Organisation for Animal Health (OIE).
Heads of FAO Reference Centres, in Australia, the People’s Republic of China, Italy and the United States of America were also in attendance, along with representatives from the Centers for Disease Control and Prevention and the United States Department of Agriculture.
“However, constant vigilance is required,” Lubroth said. “Bird flu viruses continue to circulate in poultry. Efforts must continue and be strengthened, not only in affected countries, but also in neighbouring states and areas with strong trade linkages. This is especially true for H7N9 since it causes no clinical signs in birds and is therefore very difficult to detect in poultry.”
Along these lines, FAO has committed $2 million of emergency funding supplemented by over $5 million from USAID to kick-start H7N9 response efforts. USAID support has enabled FAO to help countries at risk dramatically improve surveillance capacities.
“Several at-risk countries previously unable to pick up the virus can now accurately detect H7N9,” explained Lubroth. “Identifying the virus with consistency is critical to targeting control efforts and reducing spread.”
Dennis Carroll, Director of USAID’s Emerging Threats Program, added, “The early detection and excellent characterization of the H7N9 virus by Chinese experts has created an unprecedented opportunity to mount a coordinated effort to stop the further spread of the virus – and thwart a possible global event.
Significant progress over the past decade in forging national and international partnerships and validating interventions for control of avian influenza can be immediately adapted to addressing the threat posed by the H7N9 virus.”
Surveillance is key
FAO and USAID stress that more work is required. In the short term this includes continued, targeted surveillance and trace back throughout the production and marketing system, contingency planning and compensation scheme development.
“The emergence of the H7N9 virus serves as yet another reminder that new disease threats are not the exception, but a predictable consequence of events occurring at the human-animal interface,” said Carroll.
“It is important we continue to monitor future threats while at the same time improving the practices and behaviours associated with livestock production and marketing that can make it easier for diseases to emerge and affect animals and people,” he said.
“Surveillance is key, and with support from key partners like USAID, we’re making progress,” said Lubroth. “In addition to helping countries detect the virus, we need to make sure authorities can trace back the virus to its points of origin and better understand how the virus is circulating so as to design effective control actions. Where appropriate we need to help governments put together contingency plans for the possible detection of the virus and compensation schemes for assisting those affected by control efforts.”
In the longer-term fight against H7N9 and other viruses, FAO and USAID are urging countries to invest in improving the way they market and sell poultry.
“We need keep our eyes on the bigger picture of promoting healthy food systems, especially when it comes to animal production and marketing,” said Lubroth. “Restructuring can create healthier, safer markets by developing facilities that employ proper food safety and hygiene measures. Since animals, and therefore viruses, are inevitably gathered at markets, keeping these markets clean and safe reduces the chances for viruses and other pathogens to spread. Healthy markets mean healthy birds, and that means improved public health, better food security and more sustainable livelihoods.”
FAO continues its call for funds to bolster the global H7N9 response. FAO is urging countries to make key investments in improving markets and promoting healthy food systems to fight viruses affecting animals and humans as part of overarching efforts to ensure the animal sector realizes its potential in the promotion of healthy and productive lives.
Initiatives to help Asian countries improve virus detection, control and response
Bangkok, Thailand, 18 Sep 2013 — Two emergency regional projects* aimed at containing avian influenza were launched today by the UN Food and Agriculture Organization’s (FAO) Regional Office for Asia and the Pacific at a three-day workshop. The meeting was attended by veterinary experts from countries in the sub-regions of Southeast and South Asia and from a number of international organizations and development partners.
Working in coordination with development partners such as the United States Agency for International Development (USAID), the World Organization for Animal Health (OIE) and the World Health Organisation (WHO), these FAO projects will promote coordinated sub-regional preparedness, surveillance and response to A(H7N9) in poultry and other animal populations in Asian countries at risk. The projects will assist countries in the region to better detect, control and respond to the virus.
The emergence of A(H7N9) influenza in China raises the possibility that the virus could spread to a number of countries in the region which are members of the Association of Southeast Asian Nations (ASEAN) and South Asian Association for Regional Cooperation (SAARC). FAO said these initiatives will boost epidemiologic knowledge, surveillance and diagnostic capacity and risk management, including preparedness and response, risk communication, as well as coordination and collaboration among ASEAN and SAARC countries and between animal and human health authorities.
Countries in Asia must remain vigilant in light of possible re-emergence of A(H7N9)
Speaking at the workshop project launch, Hiroyuki Konuma, FAO Assistant Director-General and Regional Representative for Asia and the Pacific, warned the region that the “virus in China is still present and there is still a great deal not yet understood about this H7N9 virus. Other influenza viruses that circulate in poultry often decrease dramatically during the summer months, only to reappear later in the year during cold season. Also, many low pathogenic influenza viruses in poultry have transformed into highly pathogenic viruses.”
Konuma called on countries in the region to ensure that they are prepared should the H7N9 virus follow a similar path. “This means that all countries in Asia need to be vigilant– both for incursion and spread of the virus, and possible evolution to highly pathogenic type.”
Preparation needed in case there is a resurgence of the A(H7N9) virus
Konuma urged veterinary experts at the workshop to “discuss how to adjust surveillance and response mechanisms and to prepare for a possible resurgence of H7N9 suggesting that participants identify synergies of the human health, animal health and other sectors among the countries in the region and between the countries and the relevant international organizations.”
He added that the “sharing of information and the coordination that takes place at this meeting, and through the period of these projects, will lead to further improvements in infectious disease detection and response so that, as a global community, we will be better prepared for immediate action and early containment the next time a new disease emerges.”
*Emergency Assistance for Surveillance of Influenza A(H7N9) Virus in Poultry and Animal Populations in Southeast Asia – TCP/RAS/3406(E) and Emergency Assistance for Surveillance of Influenza A(H7N9) Virus in Poultry and Animal Populations in South Asia – TCP/RAS/3407(E)
The guidelines are intended to help countries identify priorities, objectives and the desired goal of disease control programmes. Disease control programmes are often established with the aim of eventual eradication of agents at a country, zone or compartment level. While this approach is desirable, the needs of stakeholders may require a broader range of outcomes. For some diseases, eradication may not be economically or practically feasible and options for sustained mitigation of disease impacts may be needed. It is important to clearly describe the programme goals and these may range from simple mitigation of disease impacts to progressive control or eradication of the disease. These guidelines highlight the importance of economic assessment of disease intervention options in the design of programmes taking into consideration effectiveness, feasibility of implementation, as well as costs and benefits. The purpose is to provide a conceptual framework that can be adapted to a particular national and epidemiological context.