FAO-OIE-WHO Joint Technical Consultation on Avian Influenza at ...

<strong>FAO</strong>-<strong>OIE</strong>-<strong>WHO</strong> <strong>Joint</strong> <strong>Technical</strong> <strong>Consultation</strong> on Avian Influenza at the Human-Animal Interfacework regarding its prevention and control, and identify keyareas for future technical collaboration between the animaland public health sectors. It was emphasized that both sectorsare jointly responsible for overcoming any barriers tosuch collaboration.It was noted that the ongoing H5N1 HPAI crisis has presentedboth challenges and opportunities to the global community,and has resulted in an unprecedented response, bothon the national and international levels. International organizationssuch as <strong>FAO</strong>, <strong>OIE</strong>, and <strong>WHO</strong> have established andimproved tools and developed global strategies to respondbetter to these challenges, have supported countries andregions, and have strengthened links with each other. Membercountries have increased their internal and regional collaborations,initiating integrated national preparedness programs,joint task forces, and interministerial committees. Achievementsin AI prevention and control were noted, includingimproved disease awareness, elimination of outbreaks in mostaffected countries and control of the disease in many others,as well as better understanding of the importance of controllingpathogens at their source, of political commitment, ofstrong veterinary and public health systems, of multidisciplinaryand multisectoral involvement, of public–private partnerships,of socio-economic analysis and advocacy, and ofeffective communication among all stakeholders.Given the international realities of globalization, climatechange, and other converging factors, it was further notedthat the risk of infectious disease outbreaks will alwaysremain and that the strategies and lessons learned from AIshould serve as the foundation of systems designed to preventand control other zoonotic diseases. It was stressedthat we must invest in the improvement of general toolsand methodologies related to early detection, active andpassive surveillance, preparedness, emergency response,communication, and collaboration, including the fundingof collaborative activities to study infectious diseases at thehuman–animal interface. It was also emphasized that stepsalready taken by animal health and public health organizationsin confronting H5N1 in a collaborative and integratedmanner must be made self-sustaining, so that progress cancontinue even after short term funding flows cease or areredirected to other areas of zoonotic disease.2 Virological characteristics of influenzaviruses (Session 1)The objective of this session was to identify virologicalcharacteristics important for zoonotic and pandemic disease.Speakers presented data on the distribution and phylogenyof H5N1 and other zoonotic AIVs; the effects ofsingle mutations and virus-level factors on influenza transmissibility,infectivity, and pathogenicity in humans; receptorsand host specificity; the zoonotic potential of otherAIVs; which specific virus characteristics are of interest forpublic health; and the occurrence of these characteristics incirculating animal viruses.2.1 Epidemiology, distribution, and phylogeny ofcurrently circulating animal influenza virusesH5N1 avian influenza in poultry and humansThe currently circulating H5N1 AIV was first identified inanimals in 1996 and first caused disease in humans in1997. Since 2003, it has caused widespread animal outbreaksand associated human cases, as it has spread inpoultry and wild birds across Asia, Africa, and Europe andaffected domestic poultry, wild birds, and several mammalianspecies in more than 60 nations. The virus is nowendemic in poultry in several countries. The disease can beeffectively controlled in poultry when appropriate measuresare correctly applied, 2 but such application requires astrong veterinary infrastructure, investment of significantresources, and cooperation among all stakeholders.Introduction of H5N1 into a country may occur throughimportation of captive birds, movement of infected poultryand products, indirect mechanical transmission via contaminatedequipment and materials, and ⁄ or movement ofwild birds. It was generally agreed that in developed countries,legal movement of poultry (e.g., eggs and day oldchicks) poses negligible risk due to extensive industry regulation,but illegal movement of poultry poses great risks.While the role of wild birds has remained controversial, itwas agreed that wild bird migration has been responsiblefor some instances of long distance virus spread (e.g., intosome European countries) but that the maintenance ofvirus in poultry in many endemic regions is the result oflocal poultry trade rather than re-introduction of virusesvia wild birds. It was agreed that the exact method of specificintroductions into individual countries generallyremains undetermined.From 2003 through October, 2008, 387 human cases ofH5N1 have been confirmed in 15 countries in Asia, Africa,and Europe. Of these, 245 were fatal, giving a case fatalityrate (CFR) that ranges from 44 to 81% depending on thecountry. Human CFR is likely influenced by time to presentationat a health care facility, appropriateness of clinicalmanagement, surveillance bias in case detection, and populationcharacteristics. Most human H5N1 cases haveoccurred where the disease is entrenched in the poultrypopulations, and exposures have been to avian (rather thanhuman) virus sources, re-emphasizing the importance ofdisease control in the avian reservoir. To date, virus clades2 Guidelines are available from <strong>OIE</strong>(http://www.oie.int/eng/normes/mcode/en_sommaire.htm) and <strong>FAO</strong>(http://www.fao.org/avianflu/en/animalhealthdocs.html)ª 2010 <strong>FAO</strong>, <strong>OIE</strong> and <strong>WHO</strong>, Influenza and Other Respiratory Viruses, 4 (Suppl. 1), 1–29 3