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1.
Tanimura N Tsukamoto K Okamatsu M Mase M Imada T Nakamura K Kubo M Yamaguchi S Irishio W Hayashi M Nakai T Yamauchi A Nishimura M Imai K 《Veterinary pathology》2006,43(4):500-509
Highly pathogenic H5N1 avian influenza viruses were isolated in 9 large-billed crows that died in Kyoto and Osaka prefectures in Japan from March to April in 2004. We studied 3 of the 9 crows using standard histologic methods, immunohistochemistry, and virus isolation. The most prominent lesions were gross patchy areas of reddish discoloration in the pancreas. The consistent histologic lesions included severe multifocal necrotizing pancreatitis, focal degeneration and necrosis of neuron and glial cells in the central nervous system, and focal degeneration of cardiac myocytes. All of these tissues contained immunohistochemically positive influenza viral antigens. The virus was isolated from the brain, lung, heart, liver, spleen, and kidney of the crows examined. Thus we concluded that highly pathogenic avian influenza virus was associated with clinical disease, severe pathologic changes, and death in the 3 crows. 相似文献
2.
Samad RA Nomura N Tsuda Y Manzoor R Kajihara M Tomabechi D Sasaki T Kokumai N Ohgitani T Okamatsu M Takada A Sakoda Y Kida H 《The Japanese journal of veterinary research》2011,59(1):23-29
Inactivated influenza virus vaccine prepared from a non-pathogenic influenza virus strain A/duck/Hokkaido/Vac-1/2004 (H5N1) from the virus library conferred protective immunity to chickens against the challenge of antigenically drifted highly pathogenic avian influenza virus (HPAIV), A/whooper swan/Hokkaido/1/2008 (H5N1). The efficacy of the vaccine was comparable to that prepared from genetically modified HPAIV strain deltaRRRRK rg-A/ whooper swan/Mongolia/3/2005 (H5N1), which is more antigenically related to the challenge virus strain, in chickens. 相似文献
3.
This investigation assessed the susceptibility of experimentally infected pigeons to the highly pathogenic avian influenza virus (HPAIV) H5N1 that caused recent outbreaks of avian influenza in birds and humans in several countries of Asia. For this purpose 14 pigeons were infected ocularly and nasally with 10(8) EID50 and clinical signs were recorded and compared with five chickens infected simultaneously as positive controls. The chickens demonstrated anorexia, depression, and 100% mortality within 2 days postinoculation. Three of the pigeons died after a history of depression and severe neurological signs consisting of paresis to paralysis, mild enteric hemorrhage, resulting in a mortality of 21%. Gross lesions in these pigeons were mild and inconsistent. Occasionally subcutaneous hyperemia and hemorrhage and cerebral malacia were observed. Microscopic lesions and detection of viral antigen were confined to the central nervous system of these pigeons. In the cerebrum and to a minor extent in the brain stem a lymphohistiocytic meningoencephalitis with disseminated neuronal and glial cell necrosis, perivascular cuffing, glial nodules, and in one bird focally extensive liquefactive necrosis could be observed. The remaining nine pigeons showed neither clinical signs nor gross or histological lesions associated with avian influenza, although seroconversion against H5 indicated that they had been infected. These results confirm that pigeons are susceptible to HPAIV A/chicken/Indonesia/2003 (H5N1) and that the disease is associated with the neurotropism of this virus. Although sentinel chickens and most pigeons did not develop disease, further experiments have to elucidate whether or not Columbiformes are involved in transmission and spread of highly pathogenic avian influenza. 相似文献
4.
Bertran K Pérez-Ramírez E Busquets N Dolz R Ramis A Darji A Abad FX Valle R Chaves A Vergara-Alert J Barral M Höfle U Majó N 《Veterinary research》2011,42(1):24
ABSTRACT: An experimental infection with highly pathogenic avian influenza virus (HPAIV) and low pathogenic avian influenza virus (LPAIV) was carried out in red-legged partridges (Alectoris rufa) in order to study clinical signs, gross and microscopic lesions, and viral distribution in tissues and viral shedding. Birds were infected with a HPAIV subtype H7N1 (A/Chicken/Italy/5093/1999) and a LPAIV subtype H7N9 (A/Anas crecca/Spain/1460/2008). Uninoculated birds were included as contacts in both groups. In HPAIV infected birds, the first clinical signs were observed at 3 dpi, and mortality started at 4 dpi, reaching 100% at 8 dpi. The presence of viral antigen in tissues and viral shedding were confirmed by immunohistochemistry and quantitative real time RT-PCR (qRRT-PCR), respectively, in all birds infected with HPAIV. However, neither clinical signs nor histopathological findings were observed in LPAIV infected partridges. In addition, only short-term viral shedding together with seroconversion was detected in some LPAIV inoculated animals. The present study demonstrates that the red-legged partridge is highly susceptible to the H7N1 HPAIV strain, causing severe disease, mortality and abundant viral shedding and thus contributing to the spread of a potential local outbreak of this virus. In contrast, our results concerning H7N9 LPAIV suggest that the red-legged partridge is not a reservoir species for this virus. 相似文献
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Klopfleisch R Wolf PU Uhl W Gerst S Harder T Starick E Vahlenkamp TW Mettenleiter TC Teifke JP 《Veterinary pathology》2007,44(3):261-268
In early 2006, the highly pathogenic avian influenza virus (HPAIV) H5N1 of the Asian lineage caused the death of wild aquatic birds in Northern Germany. In the mainly affected areas, a trans-species transmission of HPAIV H5N1 to mammals occurred between birds and domestic cats and 1 Stone Marten (Martes foina), respectively. Here, we report lesions and distribution of influenza virus antigen in 3 cats infected naturally with HPAIV H5N1 A/swan/Germany/R65/06. The hemagglutinin partial nucleotide sequences of the viruses were genetically closely related to a H5N1 HPAIV obtained from a dead Whooper Swan (Cygnus cygnus) of the same area. At necropsy, within the patchy dark-red and consolidated lungs, there was granulomatous pneumonia caused by Aelurostrongylus sp. Histologically, the main findings associated with influenza in all cats were bronchointerstitial pneumonia and marked random hepatic necrosis. In addition, all animals displayed lymphoid necrosis in the spleen and Peyer's patches and necrosis of the adrenal cortex. Immunohistochemically, nucleoprotein of HPAIV was present intralesionally in the lungs, liver, adrenal glands, and lymphoid tissues. Oropharyngeal swabs were shown to be suited to detect HPAIV by quantitative real-time polymerase chain reaction (RT-PCR) in these cats, despite the paucity of influenza virus antigen in the upper respiratory tract by means of immunohistochemistry. The results show that outdoor cats in areas affected by HPAIV in wild birds are at risk for lethal infection. In conclusion, hepatic necrosis was, besides bronchointerstitial pneumonia, the primary lesion, suggesting that in naturally infected cats, damage to the liver plays an important role in the pathogenesis of H5N1 influenza. 相似文献
6.
Vascellari M Granato A Trevisan L Basilicata L Toffan A Milani A Mutinelli F 《Veterinary pathology》2007,44(5):635-642
The ongoing H5N1 Asian epidemic is currently affecting a number of avian species including ducks. These birds are an important part of the poultry industry in the affected countries, and it is likely that they are acting as a reservoir of infection. Ten Pekin ducks were challenged with 100 microl containing 10(7) 50% egg infective dose of the highly pathogenic avian influenza virus (HPAIV) A/Duck/Vietnam/12/05 (H5N1), administered by an intra-nasal and oral route. Clinical symptoms were recorded twice a day up to 14 days postinfection (dpi). Clinical signs were first noted at 2 dpi, with conjunctivitis and slight depression, and progressed over a period of 1-3 days to severe neurologic signs consisting of torticollis, incoordination, tremors, and seizures. Survival times varied from 3 to 7 dpi. On postmortem examination, hemorrhages were observed in the duodenum, ceca, proventriculus, ventriculus, trachea, pancreas, and brain. Histologic lesions, as well as immunohistochemistry positivity, were recorded in the pancreas and brain. In situ hybridization revealed viral antigen associated with acinar pancreatic cells, bronchial epithelial cells, and with cells of the central nervous system as well as neurons of the submucosal plexus of the duodenum. Our experimental findings agree with those previously observed in ducks naturally infected with HPAIV H5N1 viruses, confirming the acquired viral neurotropism and pancreatotropism, as previously noted in other avian species, as well as in humans. 相似文献
7.
Yamamoto Y Nakamura K Kitagawa K Ikenaga N Yamada M Mase M Narita M 《Avian diseases》2007,51(3):744-749
To evaluate the possibility of virus transmission through feathers of call ducks, we performed two experiments, intranasal infection study and transmission study, using the Japanese H5N1 highly pathogenic avian influenza virus (HPAIV) A/chicken/Yamaguchi/7/2004 (Ck/Yama/7/04). In Experiment 1, 1-day-old, 2-wk-old, and 4-wk-old birds were inoculated intranasally with Ck/Yama/7/04. Birds in all age groups exhibited necrosis and/or viral antigens in the feather epithelium. Nonpurulent encephalitis and focal necrosis of the pancreas and heart also were common to inoculated birds. In Experiment 2, nine 2-wk-old birds that were orally inoculated with feathers of an infected call duck exhibited the nonpurulent encephalitis, necrosis of the feather epithelium, and focal necrosis of the pancreas and heart, accompanied by viral antigens. These lesions were similar to those in intranasal infection. Some birds were positive for the virus isolation from cloacal swabs and hemagglutination inhibition antibody. The infection was confirmed in seven of nine birds. This study confirmed that the Japanese HPAIV can replicate in the feather epithelium, causing necrosis in call ducks through the natural infection route. It also suggests that feathers of call ducks infected with Ck/Yama/7/04 can be a potential source of infection for unaffected birds in nature. 相似文献
8.
Zoonotic agents challenging the world every year afresh are influenza A viruses. In the past, human pandemics caused by influenza A viruses had been occurring periodically. Wild aquatic birds are carriers of the full variety of influenza virus A subtypes, and thus, most probably constitute the natural reservoir of all influenza A viruses. Whereas avian influenza viruses in their natural avian reservoir are generally of low pathogenicity (LPAIV), some have gained virulence by mutation after transmission and adaptation to susceptible gallinaceous poultry. Those so-called highly pathogenic avian influenza viruses (HPAIV) then cause mass die-offs in susceptible birds and lead to tremendous economical losses when poultry is affected. Besides a number of avian influenza virus subtypes that have sporadically infected mammals, the HPAIV H5N1 Asia shows strong zoonotic characteristics and it was transmitted from birds to different mammalian species including humans. Theoretically, pandemic viruses might derive directly from avian influenza viruses or arise after genetic reassortment between viruses of avian and mammalian origin. So far, HPAIV H5N1 already meets two conditions for a pandemic virus: as a new subtype it has been hitherto unseen in the human population and it has infected at least 438 people, and caused severe illness and high lethality in 262 humans to date (August 2009). The acquisition of efficient human-to-human transmission would complete the emergence of a new pandemic virus. Therefore, fighting H5N1 at its source is the prerequisite to reduce pandemic risks posed by this virus. Other influenza viruses regarded as pandemic candidates derive from subtypes H2, H7, and H9 all of which have infected humans in the past. Here, we will give a comprehensive overview on avian influenza viruses in concern to their zoonotic potential. 相似文献
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中国H5N1亚型高致病性禽流感病毒抗原变异株的鉴定分析 总被引：2，自引：0，他引：2
对引起中国2006年山西、宁夏2省(区)H5N1亚型禽流感疫情的代表毒株——A/chicken/Shanxi/2/2006(H5N1)(CK/SX/06)进行了全面研究。结果表明该病毒具有高致病性禽流感病毒(HPAIV)特征,基因组序列分析发现其8个基因片段与中国传统H5N1亚型禽流感病毒GS/GD/1/96(H5N1)存在较大差异,属于新的基因型——山西鸡型;抗原性分析结果表明其在抗原性方面与GS/GD/1/96同样存在较大变异,将其命名为"山西鸡型"抗原变异株;以106EID50.0.1 mL-1剂量将该病毒经鼻腔接种4周龄SPF鸭以评价其对水禽的感染能力,结果表明其不感染鸭;常规方法接种BALB/c小鼠以评价其对哺乳动物的感染和致病能力,结果表明其能感染小鼠,但不引起死亡,呈低致病力。说明该类型高致病性H5N1 HPAIV目前仅危害鸡,不具备感染水禽的能力,感染哺乳动物但不致死。该类型病毒的出现与流行为中国禽流感的免疫与防制提出新的课题。 相似文献
11.
Antonio Ramis Geert van Amerongen Marco van de Bildt Loneke Leijten Raphael Vanderstichel Albert Osterhaus Thijs Kuiken 《Veterinary research》2014,45(1)
Historically, highly pathogenic avian influenza viruses (HPAIV) rarely resulted in infection or clinical disease in wild birds. However, since 2002, disease and mortality from natural HPAIV H5N1 infection have been observed in wild birds including gulls. We performed an experimental HPAIV H5N1 infection of black-headed gulls (Chroicocephalus ridibundus) to determine their susceptibility to infection and disease from this virus, pattern of viral shedding, clinical signs, pathological changes and viral tissue distribution. We inoculated sixteen black-headed gulls with 1 × 104 median tissue culture infectious dose HPAIV H5N1 (A/turkey/Turkey/1/2005) intratracheally and intraesophageally. Birds were monitored daily until 12 days post inoculation (dpi). Oropharyngeal and cloacal swabs were collected daily to detect viral shedding. Necropsies from birds were performed at 2, 4, 5, 6, 7, and 12 dpi. Sampling from selected tissues was done for histopathology, immunohistochemical detection of viral antigen, PCR, and viral isolation. Our study shows that all inoculated birds were productively infected, developed systemic disease, and had a high morbidity and mortality rate. Virus was detected mainly in the respiratory tract on the first days after inoculation, and then concentrated more in pancreas and central nervous system from 4 dpi onwards. Birds shed infectious virus until 7 dpi from the pharynx and 6 dpi from the cloaca. We conclude that black-headed gulls are highly susceptible to disease with a high mortality rate and are thus more likely to act as sentinel species for the presence of the virus than as long-distance carriers of the virus to new geographical areas.
Electronic supplementary material
The online version of this article (doi:10.1186/s13567-014-0084-9) contains supplementary material, which is available to authorized users. 相似文献12.
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The transfer of maternal antibodies to offspring can effectively protect against avian influenza virus (AIV) infection during early life in chickens and can prevent AIV spread by decreasing the overall percentage of the avian population susceptible to this pathogen. Herein, we evaluated maternal antibody transfer dynamics in whooper swans (Cygnus cygnus), which represent an important AIV host species. In total, 57 eggs from 19 nests were collected to study the relationship between egg yolk AIV-specific antibody concentrations and factors including egg size, laying order, maternal serum AIV antibody titer, and maternal body condition. Overall, we found that AIV-specific antibodies were present in the serum of 63.2 % of surveyed female swans and were transferred to 50.8 % of analyzed eggs. We found maternal AIV-specific antibody concentration and body weight to be positively correlated with egg yolk AIV antibody concentration, whereas egg laying order was negatively correlated with yolk antibody titer. Overall, these findings maternal transfer of AIV-specific antibodies may function as a key mechanism governing the dynamics of AIV infection in swan populations. 相似文献
14.
Avian influenza A H5N1 infections in cats 总被引：1，自引：0，他引：1
Although cats had been considered resistant to disease from influenza virus infection, domestic cats and large felids are now known to be naturally und experimentally susceptible to infection with highly pathogenic avian influenza virus H5N1 (HPAIV H5N1). The virus causes systemic infection, lung and liver being the mainly affected organs. Infected cats show fever, depression, dyspnoea, and neurological signs, but subclinical infections have also occurred. Mostly, cats have been infected by direct contact with affected birds, especially by eating raw poultry; transmission from cat to cat may also occur. Little is known about the role of cats in the epidemiology of the virus. So far, no reassortment between avian and mammalian influenza viruses has occurred in cats, but experts fear that cats might give the virus an opportunity to adapt to mammals. This publication gives a review on avian influenza in cats with a focus on practical aspects for veterinarians. 相似文献
15.
禽流感病毒（avian influenza virus,AIV）是一种重要的人兽共患病病原,严重制约养禽业的健康发展,并对公共卫生安全构成极大威胁。其中,H5（H5N1、H5N2、H5N6、H5N8等）和H7N9亚型高致病性禽流感病毒（highly pathogenic avian influenza virus,HPAIV）引起的高致病性禽流感（highly pathogenic avian influenza,HPAI）对我国养禽业危害巨大。通过实施强制免疫,疫情得到了控制,但在禽群中仍散状暴发,并出现多种新型病毒,防控形势依然严峻。本文总结了截至2021年9月我国禽类暴发H5和H7N9亚型HPAI的所有官方公布的疫情暴发事件以及监测数据,分析了其流行特点,以期为禽流感的预警和防控提供参考。 相似文献
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Prevalence of influenza A H5N1 virus in cats from areas with occurrence of highly pathogenic avian influenza in birds 总被引：1，自引：1，他引：0
Marschall J Schulz B Harder Priv-Doz TC Vahlenkamp Priv-Doz TW Huebner J Huisinga E Hartmann K 《Journal of Feline Medicine and Surgery》2008,10(4):355-358
Natural and experimental infections have shown that cats are susceptible to highly pathogenic avian influenza A virus subtype H5N1 (HPAIV H5N1). Cats can be severely affected and die from the disease, but subclinical infections have also been reported. To learn more about the role of cats in the spread of the virus and about the risk posed to cats, the prevalence of H5N1 virus was examined in 171 cats from areas in Germany and Austria in which birds infected with HPAIV H5N1 had been found. Pharyngeal swabs were examined for H5N1 virus using real-time polymerase chain reaction, and serum samples were tested for antibodies to influenza virus. None of the cats showed evidence of infection with H5N1 virus. Prevalence of H5N1 virus was determined to be <1.8% (95% confidence interval (CI): 0.000000-0.017366); prevalence of antibodies was <2.6% (95% CI: 0.000000-0.025068). 相似文献
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Kajihara M Matsuno K Simulundu E Muramatsu M Noyori O Manzoor R Nakayama E Igarashi M Tomabechi D Yoshida R Okamatsu M Sakoda Y Ito K Kida H Takada A 《The Japanese journal of veterinary research》2011,59(2-3):89-100
In 2010, an H5N1 highly pathogenic avian influenza virus (HPAIV) was isolated from feces of apparently healthy ducks migrating southward in Hokkaido, the northernmost prefecture of Japan. The H5N1 HPAIVs were subsequently detected in domestic and wild birds at multiple sites corresponding to the flyway of the waterfowl having stopovers in the Japanese archipelago. The Hokkaido isolate was genetically nearly identical to H5N1 HPAIVs isolated from swans in the spring of 2009 and 2010 in Mongolia, but less pathogenic in experimentally infected ducks than the 2009 Mongolian isolate. These findings suggest that H5N1 HPAIVs with relatively mild pathogenicity might be selected and harbored in the waterfowl population during the 2009-2010 migration seasons. Our data provide "early warning" signals for preparedness against the unprecedented situation in which the waterfowl reservoirs serve as perpetual sources and disseminators of HPAIVs. 相似文献
20.
Ramp K Veits J Deckers D Rudolf M Grund C Mettenleiter TC Römer-Oberdörfer A 《Avian diseases》2011,55(3):413-421
To analyze the contribution of neuraminidase (NA) toward protection against avian influenza virus (AIV) infection, three different recombinant Newcastle disease viruses (NDVs) expressing hemagglutinin (HA) or NA, or both, of highly pathogenic avian influenza virus (HPAIV) were generated. The lentogenic NDV Clone 30 was used as backbone for the insertion of HA of HPAIV strain A/chicken/Vietnam/P41/05 (H5N1) and NA of HPAIV strain A/duck/Vietnam/TG24-01/05 (H5N1). The HA was inserted between the genes encoding NDV phosphoprotein (P) and matrixprotein (M), and the NA was inserted between the fusion (F) and hemagglutinin-neuraminidase protein (HN) genes, resulting in NDVH5VmPMN1FHN. Two additional recombinants were constructed carrying the HA gene between the NDV P and M genes (NDVH5VmPM) or the NA between F and HN (NDVN1FHN). All recombinants replicated well and stably expressed the HA gene, the NA gene, or both. Chickens immunized with NDVH5VmPMN1FHN or NDVH5VmPM were protected against two different HPAIV H5N1 and also against HPAIV H5N2. In contrast, immunization of chickens with NDVN1FHN induced NDV- and AIV N1-specific antibodies but did not protect the animals against a lethal dose of HPAIV H5N1. Furthermore, expression of AIV N1, in addition to AIV H5 by NDV, did not increase protection against HPAIV H5N1. 相似文献