Swayne David E
OIE Collaborating Center for Research on Emerging Avian Diseases, Southeast Poultry Research Laboratory, Agricultural Research Service, U.S. Department of Agriculture, 934 College Station Road, Athens, GA 30605, USA.
Avian Dis. 2012 Dec;56(4 Suppl):818-28. doi: 10.1637/10183-041012-Review.1.
There are 30 recorded epizootics of H5 or H7 high pathogenicity avian influenza (HPAI) from 1959 to early 2012. The largest of these epizootics, affecting more birds and countries than the other 29 epizootics combined, has been the H5N1 HPAI, which began in Guangdong China in 1996, and has killed or resulted in culling of over 250 million poultry and/or wild birds in 63 countries. Most countries have used stamping-out programs in poultry to eradicate H5N1 HPAI. However, 15 affected countries have utilized vaccination as a part of the control strategy. Greater than 113 billion doses were used from 2002 to 2010. Five countries have utilized nationwide routine vaccination programs, which account for 99% of vaccine used: 1) China (90.9%), 2) Egypt (4.6%), 3) Indonesia (2.3%), 4) Vietnam (1.4%), and 5) Hong Kong Special Administrative Region (< 0.01%). Mongolia, Kazakhstan, France, The Netherlands, Cote d'Ivoire, Sudan, North Korea, Israel, Russia, and Pakistan used < 1% of the avian influenza (AI) vaccine, and the AI vaccine was targeted to either preventive or emergency vaccination programs. Inactivated AI vaccines have accounted for 95.5% of vaccine used, and live recombinant virus vaccines have accounted for 4.5% of vaccine used. The latter are primarily recombinant Newcastle disease vectored vaccine with H5 influenza gene insert. China, Indonesia, Egypt, and Vietnam implemented vaccination after H5N1 HPAI became enzootic in domestic poultry. Bangladesh and eastern India have enzootic H5N1 HPAI and have not used vaccination in their control programs. Clinical disease and mortality have been prevented in chickens, human cases have been reduced, and rural livelihoods and food security have been maintained by using vaccines during HPAI outbreaks. However, field outbreaks have occurred in vaccinating countries, primarily because of inadequate coverage in the target species, but vaccine failures have occurred following antigenic drift in field viruses within China, Egypt, Indonesia, Hong Kong, and Vietnam. The primary strategy for HPAI and H5/H7 low pathogenicity notifiable avian influenza control will continue to be immediate eradication using a four-component strategy: 1) education, 2) biosecurity, 3) rapid diagnostics and surveillance, and 4) elimination of infected poultry. Under some circumstances, vaccination can be added as an additional tool within a wider control strategy when immediate eradication is not feasible, which will maintain livelihoods and food security, and control clinical disease until a primary strategy can be developed and implemented to achieve eradication.
1959年至2012年初，共记录到30起H5或H7高致病性禽流感（HPAI）疫情。其中规模最大的疫情是H5N1 HPAI，受影响的禽类和国家数量超过其他29起疫情的总和。该疫情于1996年在中国广东爆发，已导致63个国家超过2.5亿只家禽和/或野鸟死亡或被扑杀。大多数国家采用扑杀家禽的方案来根除H5N1 HPAI。然而，15个受影响国家将疫苗接种作为控制策略的一部分。2002年至2010年期间使用的疫苗剂量超过1130亿剂。五个国家实施了全国性常规疫苗接种计划，其疫苗使用量占总量的99%：1）中国（90.9%），2）埃及（4.6%），3）印度尼西亚（2.3%），4）越南（1.4%），5）香港特别行政区（<0.01%）。蒙古、哈萨克斯坦、法国、荷兰、科特迪瓦、苏丹、朝鲜、以色列、俄罗斯和巴基斯坦的禽流感（AI）疫苗使用量不到1%，且AI疫苗主要用于预防性或应急性疫苗接种计划。灭活AI疫苗占疫苗使用量的95.5%，活重组病毒疫苗占4.5%。后者主要是插入H5流感基因的重组新城疫载体疫苗。中国、印度尼西亚、埃及和越南在H5N1 HPAI在家禽中成为地方病后实施了疫苗接种。孟加拉国和印度东部存在H5N1 HPAI地方病，但在其控制计划中未使用疫苗接种。在HPAI疫情期间使用疫苗预防了鸡的临床疾病和死亡，减少了人间病例，维持了农村生计和粮食安全。然而，疫苗接种国家仍发生了野外疫情，主要原因是目标物种的疫苗接种覆盖率不足，但在中国、埃及、印度尼西亚、香港和越南，由于野外病毒的抗原漂移，也出现了疫苗失效的情况。HPAI以及H5/H7低致病性应报告禽流感控制的主要策略将继续是采用四管齐下的策略立即根除：1）教育，2）生物安全，3）快速诊断和监测，4）扑杀感染家禽。在某些情况下，当立即根除不可行时，可在更广泛的控制策略中增加疫苗接种作为额外手段，这将维持生计和粮食安全，并控制临床疾病，直到制定并实施主要策略以实现根除。
