我国禽流感等禽病防控六大新策略

近年来我国禽流感等禽病不仅导致巨额经济损失,而且对公共卫生构成严重威胁,受到全社会和全球广泛关注。本文首先分析我国养禽业基本现状和发展趋势、我国禽病防控困难所在,以及现有防控策略的不足,提出和分析六个禽病防控新策略：设立家禽防疫隔离带,即设立家禽限制养殖和加强检疫区,延缓疫情自然传播;加快小型养禽场退出速度,小型养禽场经济效益低,而疫情传播风险高,已是历史淘汰对象;禁止在开放的水体中饲养家禽,这类家禽易成为疫情超级传播者;推广电子活禽市场,它们不仅与其他网店相似,成本低而效益高,而且对公众的健康威胁小,禽病传播风险小;对无防疫合格证的养禽和屠宰加工场所进行适当的行政处罚,这是落实上述措施的合法途径;在境外为中国养禽,这与农业走出去和全球经济一体化发展趋势一致,能降低国内家禽饲养密度和禽病风险。     

Avian trichomoniasis: a study of lesions and relative prevalence in a variety of captive and free-living bird species as seen in an Australian avian practice

Background Studies of avian trichomoniasis in the literature are limited to some extent, often being confined to a single bird species or group of species within a bird Order. Some incidence studies have been reported for free‐living birds, and occasionally for captive birds. Very few reports describe the prevalence and types of lesions seen for a wide range of bird species, especially from a clinical perspective. Methods Retrospective study of avian practice records from a 10‐year period. Emphasis on the types of presentations and relative prevalence of trichomoniasis in a variety of captive and free‐living bird species encountered in Australian avian practice. Results The occurrence of trichomoniasis in several novel species (lorikeets, corvids and a cuckoo species), plus its distinctive presentation in southern boobook owls (Ninox boobook), is documented. Conclusion Trichomoniasis should be a differential diagnosis for birds presenting with regurgitation or upper gastrointestinal abscesses, even if motile trichomonads are not found in wet preparations from crop washes or lesions.     

Antiviral efficacy of oseltamivir against avian influenza virus in avian species

Avian influenza is one of the most contagious viral diseases in bird species and, increasingly, interspecies transmission to mammalian species has been reported. Prevention and eradication of avian influenza virus (AIV) infection in birds may require vaccines as part of a comprehensive program including biosecurity, culling, diagnostics, and surveillance. However, for valuable bird species in zoos, novel eradication strategies are needed, including antiviral treatments. The present study evaluated the anti-influenza efficacy of the potent neuraminidase inhibitor oseltamivir in avian species using the orders Galliformes (chickens) and Anseriformes (ducks). Viral replication of low pathogenic AIV was significantly reduced in the chicken model and completely reduced in the duck model. Anti-influenza drug administration to valuable bird species with an appropriate extrapolation approach could be useful for control of AIV in combination with active surveillance and vaccination strategies. Further, evaluation of oseltamivir against highly pathogenic avian influenza (HPAI) using avian models would be needed to optimize the oseltamivir application guideline for HPAI control.     

禽流感病毒非结构蛋白NS1的分子生物学特性与功能

禽流感严重威胁着世界养禽业及人类健康.随着对流感病毒研究的逐渐深入,人们已经从对流感病毒结构蛋白的研究转移到对非结构蛋白即NS1蛋白的研究上来.研究发现流感病毒的NS1蛋白与流感病毒所诱导的细胞凋亡之间存在一定的联系,其对凋亡的调节作用与流感病毒感染的细胞是否产生干扰素及其所感染的细胞系直接相关.NS1蛋白能够抑制病毒感染细胞干扰素的产生,在流感病毒颉颃干扰素的抗病毒效应中发挥了重要的作用.随着疫苗的广泛使用,无法区分野毒感染和疫苗免疫的禽群,干扰了禽流感的诊断,掩盖了禽流感的流行,增加了禽流感的预防难度.NS1蛋白作为流感病毒的非结构蛋白,具有高度的保守性,在临床应用中作为鉴别诊断免疫禽和自然感染禽的检测抗原具有广阔前景.     

Biosecurity and bird movement practices in upland game bird facilities in the United States

Since 1996, the emergence of Asian-origin highly pathogenic avian influenza subtype H5N1 has spurred great concern for the global poultry industry. In the United States, there is concern over the potential of a foreign avian disease incursion into the country. Noncommercial poultry operations, such as upland game bird facilities in the United States, may serve as a potential source of avian disease introduction to other bird populations including the commercial poultry industry, backyard flocks, or wildlife. In order to evaluate how to prevent disease transmission from these facilities to other populations, we examined biosecurity practices and bird movement within the upland game bird industry in the United States. Persons that held a current permit to keep, breed, or release upland game birds were surveyed for information on biosecurity practices, flock and release environments, and bird movement parameters. Biosecurity practices vary greatly among permit holders. Many facilities allow for interaction between wild birds and pen-reared birds, and there is regular long-distance movement of live adult birds among facilities. Results suggest that upland game bird facilities should be targeted for biosecurity education and disease surveillance efforts.     

Use of observed wild bird activity on poultry farms and a literature review to target species as high priority for avian influenza testing in 2 regions of Canada

The risk of avian influenza outbreaks in poultry is partially dependent on the probability of contact between domestic poultry and wild birds shedding avian influenza (AI) virus. The major objective of this study was to document wild bird activity on poultry farms to determine which wild bird species should be targeted for AI surveillance in Canada. We collected data in 2 major poultry producing regions of Canada, southwestern Ontario and the Fraser Valley of British Columbia, on the relative abundance of various wild bird species found on poultry farms and on how these species utilized habitat around poultry farms. We reviewed the published literature to determine what was known about AI pathobiology in the species we observed. From these results we created a list of 10 wild bird species that are a priority for further study. These species are the European starling, barn swallow, rock dove, American crow, northwestern crow, American robin, dark-eyed junco, song sparrow, horned lark, and common grackle. Abundance of these and other species varied between provinces and seasons.     

蓝鹇免疫流感疫苗后抗体消长研究

杭州动物园从北京动物园引进5对蓝鹇种源。日常食物主要是青菜、稻谷、家鸡用颗粒料、少量苹果。饲养过程中发生的主要疾病有细菌性肠炎、发情期的雄性打斗后的外伤等。杭州动物园经过精心饲养,3a繁殖达60多只。蓝鹇在杭州动物园的饲养和繁殖是全国人工饲养繁殖最好,且是全国最大人工种群。由于没有蓝鹇等野禽专用禽流感疫苗,杭州动物园使用家禽禽流感疫苗对蓝鹇进行禽流感免疫。根据家禽的禽流感免疫方法,每年对蓝鹇进行2次禽流感疫苗免疫,由于它的飞翔能力较强,每次免疫进行捕捉时均会乱飞,有时还会造成应激死亡,但最终免疫结果是否有效也未曾进行过检测。本研究中蓝鹇流感疫苗抗体检测采用的方法是：禽流感病毒H5抗体酶联免疫（ELISA）的检测方法。结果证明家禽流感疫苗对蓝鹇有效,经胸部肌肉注射0．5ml／次,每4个月肌注1次,每年免疫3次。雏鹇首免应在出壳后第8天、第9天或第10天。     

Some considerations when nursing birds in veterinary premises

This paper indicates the need for, and the benefits to be gained by, better standards of avian nursing. The subject is approached by a discussion of the behaviour of birds in general and suggests ways in which stress in the hospitalized bird can be reduced to the minimum. The dangers of young birds becoming imprinted are emphasized. The contrasts between mammalian and avian anatomy, particularly of the respiratory and renal systems, are considered together with the implications when nursing birds. There is a discussion of the avian metabolic rate, the nutrition of sick birds, and some indications for physiotherapy in birds are mentioned.     

Avian toxicology.

Owing to the unique physiology of birds, most toxicities are life-threatening and require prompt, well-informed action. It is often hard to ascertain which specific toxin or the amount of toxin to which the bird has been exposed. Therefore, the most important action is to treat the bird, not the poison. This article discusses the steps in diagnosing and treating toxicoses, from both natural and man-made toxins, that have been reported in avian species.     

Feathered dinosaurs from China and the evolution of major avian characters

Recent discoveries of feathered dinosaurs from Early Cretaceous deposits in Liaoning, China, have not only lent strongest support for the dinosaurian hypothesis of bird origins, but have also provided much‐needed information about the origins of feathers and avian flight. Preliminary analysis of character evolution suggests that the major avian osteological characters were acquired during the early evolution of maniraptoran dinosaurs. The available evidence also suggests that the first feathers with a filamentous morphology probably evolved in basal coelurosaurs and pennaceous feathers (including those with aerodynamic features) were developed in non‐avian maniraptorans, indicating that feathers evolved before the origin of birds and their flight. An evolutionary model is proposed here to describe the major stages of feather evolution, a process characterized by a combination of both transformational and innovative modifications. This model is different from some recent developmental models, which suggest that feathers are evolutionary novelties without a homologous relationship to reptilian scales. Although non‐avian theropods are traditionally regarded as distinctly cursorial animals, recent discoveries suggest that the closest relatives of birds might be arboreal theropods. Many bird features, such as the furcula and pennaceous feathers, evolved in a terrestrial context, whereas others, such as some pedal modifications, may have evolved in an arboreal context. Consequently, arboreality may have also contributed to the origin of avian flight.     

Spatiotemporal distributions of reported cases of the avian influenza H5N1 (bird flu) in Southern China in early 2004

This study investigates spatiotemporal distributions of reported cases of the avian influenza H5N1 (bird flu) in Southern China in early 2004. Forty-nine cases of the avian influenza H5N1 covering a 6-week period (January 19, 2004, through March 9, 2004) were compiled from the Chinese Ministry of Agriculture and the World Health Organization. Geographic information systems (GIS) techniques combined with statistical techniques were used to analyze the spatiotemporal variation of reported cases of avian influenza. Using Oden's direction method, we also explored the spatiotemporal interaction of individual-level avian influenza cases during the study duration. The peak period (temporal clustering) for the epidemiological avian influenza outbreak occurred between the third and fourth weeks. Although we observed a major northeast-southwest distribution of the avian influenza H5N1 cases, there was no significant spatiotemporal association in average "direction of advance" of these cases. The directional finding is very consistent with the major migratory bird routes in East Asia, but owing to weak surveillance and reporting systems in the region, the study findings warrant further evaluation.     

Collecting diagnostic samples in avian patients.

With the increasing owner demand of thorough medical evaluation of avian patients, clinicians are being required to collect meaningful diagnostic samples from bird species. The art of diagnosis stems from taking a complete medical history, performing a thorough physical examination, collecting appropriate diagnostics, and interpreting the collective information. This article focuses on methods of collecting diagnostic samples in avian patients.     

Prevalence and relevance of avian Toxoplasma gondii infections in Europe

Toxoplasma (T.) gondii is a parasitic protozoon whose life cycle includes a definite and an intermediate host. Besides a wide range of mammals also birds are suitable intermediate hosts. There are a high number of case reports, prevalence data and experimental studies regarding avian toxoplasmosis. In many domestic, wild and zoo bird species which are relevant in Europe the susceptibility for T. gondii infection could be demonstrated though susceptibility for clinical disease often seems to be low, especially in gallinaceous birds. Comprehensive Europe-wide studies concerning the occurrence of avian toxoplasmosis have not been conducted so far. The general infestation ratio of birds on European free-range poultry farms seems to be relatively high. The European wild bird population represents a significant reservoir for the pathogen. When evaluating the seroprevalence it has to be considered that sensitivity and specificity of the detection methods for T. gondii specific antigens which are used frequently in mammals often are not satisfying in birds.     

Avian mycobacteriosis in companion birds: 20-year survey

The causative agents of avian mycobacteriosis in pet birds are rarely identified. The aim of this study is to add information about the etiology of avian mycobacteriosis. The identification of mycobacterium species in 27 cases of avian mycobacteriosis in pet birds was investigated by polymerase chain reaction (PCR) and sequencing of a rRNA hypervariable region. Avian mycobacteriosis appeared to be an infrequent diagnosis. Interestingly, a few cases of avian mycobacteriosis were recorded in very young birds. The most commonly affected species were the canary (Serinus canarius), the Eurasian goldfinch (Carduelis carduelis) and the red siskin (Spinus cucullatus). All but one bird were infected with Mycobacterium genavense. Mycobacterium avium was identified only in one case.     

Diagnostic cytology in avian medicine

Diagnostic cytology in avian medicine provides a means for better disease definition in the avian patient, which allows for a more specific therapeutic regimen. It is important that cytologic specimens are from fresh sources, since cells degenerate rapidly following the death of the bird or the tissue. Cytologic evaluation is an adjunct to other diagnostic procedures. A definitive diagnosis often requires information from the clinical history, physical examination, evaluation of samples obtained from the bird, radiographs, surgical procedures, necropsy, and histopathology.     

The live bird market system and low-pathogenic avian influenza prevention in southern California

Although live bird markets (LBMs) have been associated with outbreaks of avian influenza (AI), there are some LBM systems where AI outbreaks are extremely rare events. The California LBMs have not had any detected avian influenza viruses (AIVs) since December 2005. Responses to a detailed questionnaire on the practices and characteristics of the participants in the California low-pathogenic (LP) AI control program have been described to characterize possible reasons for the lack of AI outbreaks in LBMs. Compliance with an LPAI control program that contains active surveillance, prevention, and rapid response measures by those involved in the LBM system, rendering services to dispose of carcasses, no wholesalers, and few third-party bird deliveries was associated with the lack of LPAIV circulating in the Southern California LBM system.     

野生鸟类与禽流感

野生鸟类是生态系统中不可缺少的组成部分，近年来频频发生的禽流感事件及其流行特点显示禽流感的发生与野鸟活动存在一定关系。本文介绍禽流感及近期流行特点与野生鸟类关系，并就防控禽流感保护野生鸟类提出一系列建议和方法。     

Examination and preventive medicine protocols in psittacines.

Preventive medicine is the best insurance for effective avian health maintenance and infectious disease control. Psittacine birds should have a yearly physical examination including a thorough history. Additionally, these animals require adequate management and husbandry including a commercial bird food diet supplemented with fresh fruits and vegetables. A complete preventive medicine program should include diagnostic tests as deemed necessary by the avian veterinarian in addition to strict quarantine, vaccination, and disinfection. Necropsy and histopathology are also important components of an effective preventive medicine program.     

Grassland bird response to vegetation structural heterogeneity and clearing of invasive bramble

Spatial and temporal patterns of disturbance and the subsequent heterogeneity are critical in maintaining biodiversity within grassland ecosystems. Grassland birds have evolved within this ‘shifting mosaic’ to become reliant on specific habitat characteristics maintained under varying levels of both natural and anthropogenic disturbance. Unfortunately, grasslands in South Africa have been extensively transformed and remain poorly conserved, threatening grassland avifauna. Mistbelt grassland is a threatened vegetation type endemic to the province of KwaZulu-Natal, of which only 0.3% is formally protected. This study investigated seasonal and patch type heterogeneity in a Mistbelt grassland avian community by determining avian community structure and composition in four patch types, i.e. i) untransformed open grassland, ii) burnt grassland, iii) bramble-invaded and, iv) bramble-cleared grassland, during winter and summer. Avian assemblages were significantly different between the different patch types for each season. The bramble patch type negatively affected grassland bird species diversity. Bramble-cleared grassland and untransformed grassland had similar vegetation structure and avian communities in the summer, suggesting that the grassland bird community benefitted soon after the clearing of invasive vegetation. This study provides further evidence that bird diversity is enhanced in structurally heterogeneous grassland landscapes. Furthermore, the protection and appropriate management of privately owned Mistbelt grassland, conserved in the form of rangeland, is an important refuge for threatened and endemic avifauna, such as the globally-threatened blue swallow (Hirundo atrocaerulea) and wattled crane (Bugeranus carunculatus).     

First record of avian Plasmodium DNA from mosquitoes collected in the Yaeyama Archipelago, southwestern border of Japan

We studied the prevalence of avian Plasmodium in 509 mosquitoes of 9 species collected from the Ishigaki and Iriomote islands in the Yaeyama Archipelago, located southwest from the mainland of Japan. Two identical avian Plasmodium lineages were detected from Culex (Culiciomyia) nigropunctatus. Detected lineages were phylogenetically classified into different clade to avian Plasmodium lineages from birds and mosquitoes in the mainland of Japan but identical to a lineage detected from a resident bird, White-breasted Waterken (Amaurornis phoenicurus). This is the first detection of avian Plasmodium DNA from mosquitoes in the Yaeyama Archipelago and suggested that resident birds might have been infected with an avian Plasmodium lineage specific to the studied area and C. nigropunctatus could be the candidate vector mosquito species.