禽白血病病毒感染对新城疫和禽流感疫苗免疫效果的影响

为研究禽白血病病毒(ALV)感染对新城疫(ND)和禽流感(AI)疫苗免疫效果的影响,采用ELISA方法对河南省某地方品种鸡场进行ALV-p27抗原检测,同时采集试验鸡的血清样品,检测ND、AI(H_9)和AI(H_5)亚型的免疫抗体水平,并比较了ALV经种蛋垂直传播感染1日龄雏鸡和后期感染对ND、AI疫苗免疫效果影响的差异。结果表明,ALV经种蛋垂直传播感染1日龄雏鸡,能显著降低ND、AI(H_9)和AI(H_5)疫苗免疫的抗体水平,阳性试验组与阴性组相比血清中ND、H_9、H_5(Re-6)、H_5(Re-7)和H_5(Re-8)抗体效价分别降低1.71log2、2.37log2、1.59log2、1.00log2和1.79log2;鸡群后期感染ALV,对ND和AI疫苗的免疫没有明显的抑制作用,阳性试验组与阴性组相比无显著差异。     

河南某斗鸡原种场禽白血病病毒感染状况监测

为了解河南某斗鸡原种场禽白血病病毒(ALV)感染状况,分别于2017年1、4、9、12月和2018年7月随机或全群采集该场核心鸡群雏鸡胎粪棉拭子40份、泄殖腔棉拭子973份、血清150份以及留种用公鸡精液42份,采用ELISA方法分别检测雏鸡胎粪棉拭子、泄殖腔棉拭子、精液的ALV-p27抗原和血清样品的ALV-A/B、ALV-J亚型抗体。采集33份泄殖腔棉拭子ALV-p27阳性鸡的血浆,接种DF-1细胞,分离外源性ALV,并对分离株env基因进行了序列测定和同源性分析。结果显示,初次检测的雏鸡胎粪棉拭子ALV-p27阳性率为0,之后3次检测的成年鸡泄殖腔棉拭子ALV-p27抗原阳性率分别为84.48%、88%和78.10%;血清ALV-A/B、ALV-J亚型抗体阳性率两次检测结果分别为17.14%、0%和79.31%、24.14%;留种用公鸡精液ALV-p27抗原阳性率9.52%。DF-1细胞培养共分离到6株ALV,其中2株env基因序列与ALV-A亚型SDAU09E2株、ALV-J亚型HPRS103株同源性分别为89.2%、56.4%和89.2%、56.0%。表明该核心鸡群ALV感染率较高,且以A亚型为主。     

河南地区三黄鸡ALV感染的血清学调查

采取河南省3个三黄种鸡场种鸡的泄殖腔棉拭子和蛋清样本,利用ELISA检测ALV-p27;检测血清中ALV-J、ALV-A/B两种抗体,同时采集其血液接种DF-1细胞,培养9 d后检测细胞培养液中ALV-p27。结果表明:3个种鸡场泄殖腔棉拭子抗原阳性率分别为12.36%、8.15%和24.28%;蛋清抗原阳性率分别为7.17%、5.09%和14.44%;ALV-A/B抗体阳性率分别为11.96%、6.52%、33.70%;ALV-J抗体阳性率分别为3.26%、2.17%、22.83%;DF-1细胞培养液中ALV-p27阳性率分别为8.57%、6.67%、18.52%。试验结果为下一阶段各鸡场开展净化工作提供了科学依据。     

江苏部分蛋鸡群新城疫与H5亚型禽流感免疫抗体HI效价的测定

新城疫(ND)和H5亚型高致病性禽流感(AI)是危害我国养禽业的主要疫病,目前几乎所有规模化蛋鸡场都进行疫苗的接种预防,临床上评价ND和AI免疫效果的重要指标就是疫苗免疫后抗体的血凝抑制(HI)效价.近年来,我国对H5亚型禽流感实施了强制免疫策略,目前使用的疫苗为Re-4+Re-5双价灭活疫苗.因此,为了解江苏蛋鸡群中ND和H5亚型AI免疫抗体的水平,我们分别以新城疫病毒LaSota、H5亚型禽流感的Re-4和Re-5诊断抗原作为4单位病毒,对近两年来采集的血清样品进行了抗体HI效价的测定,以了解当前规模化蛋鸡群中疫病防治的水平,进而为ND和AI的防控提供有益参考.     

不同免疫状况鸽场血清相关抗体水平测定与分析

对20个不同免疫程序鸽场的300份血样分成四组(A、B、C、D)进行新城疫、H5亚型禽流感、H7亚型禽流感、H9亚型禽流感的免疫抗体测定.结果 A组的4项抗体分别为5.65log2、5.60log2、5.75log2、6.73log2;B组的4项抗体分别为5.411og2、0、0、6.82log2;C组的4项抗体分别为...     

鸡新城疫-传染性法氏囊病-禽流感(H9亚型)三联灭活疫苗对雏鸡的免疫效力研究

为了评估鸡新城疫(ND)-传染性法氏囊病(IBD)-禽流感(AI)(H9亚型)三联灭活疫苗对雏鸡的免疫效力,采用该疫苗分别免疫1、7、10、14、21日龄SPF雏鸡和带有母源抗体的普通雏鸡,免疫后21d~28d采血测定ND血凝抑制抗体(HIAb)、IBD中和抗体(NA)及AI(H9)HIAb抗体,并用传染性法氏囊病病毒(IBDV)强毒攻击。结果显示,免疫后各不同日龄免疫组SPF雏鸡的ND HIAb、IBD NA及AI(H9)HIAb滴度分别为7.9log2~8.3log2、13.9log2~15.8log2及8.0log2~8.9log2,IBDV攻毒均100%保护;而普通雏鸡免疫后的ND HIAb、IBD NA及AI(H9)HIAb滴度,1日龄免疫组分别为5.9log2、12.1log2和5.6log2,7、10、14、21日龄免疫组分别为6.1log2~7.0log2、12.6log2~14.5log2和6.0log2~7.5log2;IBDV攻毒,1日龄免疫组普通雏鸡保护率为60%,7、14及21日龄免疫组保护率均为100%;结果证实,SPF雏鸡所产生的免疫效力要高于带有母源抗体的普通雏鸡,1日龄普通雏鸡免疫所产生的免疫效力明显低于其他日龄。根据试验结果,推荐该疫苗对雏鸡的使用日龄为7日龄~14日龄。     

不同日龄黄鸡4种免疫抑制病血清学调查及其与3种疫病免疫效果的相关性分析

在某规模化鸡场的临床健康三黄肉鸡群中,于不同日龄采血,检测禽白血病(AL)AB亚群、J亚群,网状内皮组织增生症(RE)和传染性贫血(CIA)等4种免疫抑制性疫病的感染抗体,以及新城疫(ND)、禽流感(AI)H5亚型和传染性支气管炎(IB)的免疫抗体水平。结果发现鸡群受到ALV-AB、REV和CIAV感染。ALV-AB抗体阳性率为60%,ALV-J亚群抗体未检出,REV为75%,CIAV为100%。NDV免疫后平均抗体水平6 Log2;AIV H5抗体水平达到9.75 Log2;IBV阳性率100%,但在试验过程出现一次隐性感染。对上述7种疫病抗体阳性率或抗体水平进行相关性分析,未能找到明显的相关性规律。     

重组禽流感病毒灭活疫苗(H5N1亚型,Re-1株)免疫鸡抗体消长规律及免疫程序的初步研究

研究新型重组H5N1亚型禽流感灭活疫苗对种鸡和肉鸡的免疫原性,并对雏鸡母源抗体和免疫后的抗体进行动态观察,根据试验结果推荐该疫苗对鸡的免疫程序。用HI方法检测种鸡、肉鸡的母源抗体和免疫抗体,根据母源抗体的衰减和免疫抗体的消长规律确定首免和再免日龄。结果表明种鸡的母源抗体约能维持10 d多;0.3 mL/羽首免后10 d HI抗体就可达到6.40 log2,3-5周达到高峰期,至免疫17周后(19周龄)HI抗体水平仍然维持在4.88 log2;19周龄时0.5 mL/羽进行二免,有效抗体能维持约20周;280日龄0.5 mL/羽三免后抗体水平均一,下降缓慢,至种鸡淘汰时(三免后29周)抗体水平仍能维持在5.32 log2。肉鸡母源抗体约能维持7d,10日龄时0.3 mL/羽免疫,有效抗体能维持到上市。新型重组H5N1亚型禽流感灭活疫苗对鸡的免疫原性确实。     

H5亚型禽流感Re-4毒株疫苗免疫效果调查与分析

为了解H5亚型禽流感Re-4毒株疫苗免疫效果,采用血凝-血凝抑制试验(HA-HI)方法对16个县区102个规模场/散养户送检的1621份鸡血清,进行H5亚型禽流感Re-4毒株免疫抗体检测。结果:Re-4毒株免疫血清抗体合格率为72.9%(抗体滴度≥5log2),Re-4毒株免疫抗体合格率高于50%的蛋鸡场户占80.4%,免疫抗体滴度≥7log2的血清份数占合格数的76.2%;发生过H5亚型禽流感疫情和疑似H5亚型禽流感疫情地区的17个养鸡场户,鸡群抗体滴度≥7log2的血清比例占到免疫合格数90%以上。     

鸡HPAI(H5)和ND免疫抗体水平调查

<正>为了解全省HPAI(H5)和ND的免疫抗体水平,我们对全省范围内的规模饲养和散养鸡HPAI(H5)和ND免疫抗体水平进行了调查,现报告如下:1材料与方法1.1疫苗种类H5亚型流感为灭活苗,ND为L+IB/L+H5亚型流感二联苗。     

Heartworm in dogs in Canada in 1984

In late December 1984, 1853 institutional veterinarians and small and mixed animal clinics across Canada were sent a questionnaire in order to assess the status of Dirofilaria immitis in Canada in 1984 and 35% of them responded. Veterinarians reported that 97,794 dogs were blood-tested to check for microfilariae and 1417 dogs (1.45% of those tested) were found with heartworm. Another 34 dogs were amicrofilaremic, but were diagnosed as having heartworm disease, to give the total number diagnosed in 1984 as 1451 (1.48%). Heartworm was reported from all provinces except Prince Edward Island and Newfoundland but most (1310) of the cases were in Ontario. In Quebec, 126 cases were reported mostly from west of Montreal.

Heartworm was found most frequently in companion dogs over three years of age maintained mainly outdoors in rural areas. About 27% of the cases were observed with clinical signs of heartworm disease and 72% had a history of not having left Canada. Southwestern Ontario continued to be the primary focus of the infection.

     

Heartworm in dogs in Canada in 1983

In late December 1983, 2 800 veterinarians across Canada were sent a questionnaire in order to assess the status of heartworm disease in Canada in 1983 and 26% of them responded. Veterinarians reported that 59 504 dogs were blood-tested to check for microfilariae and 771 dogs (1.30% of those tested) were found with Dirofilaria immitis. Heartworm disease was diagnosed in all provinces except New Brunswick and Newfoundland but most (733) of the cases were in Ontario.

Heartworm disease was found most frequently in companion dogs over three years of age maintained mainly outdoors in rural areas. About 31% of the cases were observed with clinical signs of heartworm disease and 64% had a history of not having left Canada. Southwestern Ontario continues to be the focus of the infection and most of the dogs there had not left the province previously.

     

Heartworm in dogs in Canada in 1991

In late November 1991, 1883 clinics in Canada were sent a questionnaire to assess the status of Dirofilaria immitis in dogs in 1991 and there was a 60.0% response. There were 344,031 dogs tested for heart-worm (HW), 627 were found infected and the prevalence of HW infection was 0.18%. There were 417 dogs with HW in Ontario, 116 in Manitoba, 38 in Quebec, 53 in British Columbia, three in Alberta, and one in Nova Scotia. In British Columbia, all of the infected dogs but one were from the Okanagan valley which, as from 1991, is a new focus of infection in Canada. Most dogs with HW had not been on preventive medication in 1990, and the prevalence among dogs tested and unprotected was 0.59%. That prevalence was considerably higher in endemic areas. Companion dogs, over three years of age and maintained primarily outdoors in rural areas, were most frequently infected. One cat was diagnosed with D. immitis and 33 dogs had Dipetalonema reconditium.     

Heartworm in dogs in Canada in 1985

In late December 1985, 1485 institutional veterinarians and small and mixed animal clinics across Canada were sent a questionnaire in order to assess the status of Dirofilaria immitis in Canada in 1985 and 44% of them responded. Veterinarians reported that 137,300 dogs were blood-tested to check for microfilariae and 1210 dogs were found with heartworm. Another 36 dogs were amicrofilaremic but diagnosed with heartworm disease to give the total number diagnosed in 1985 as 1247 (0.91%).

Heartworm was reported from all provinces except Prince Edward Island, Newfoundland and Saskatchewan but most (1126) of the cases were in Ontario. Southwestern Ontario continued to be the primary focus of the infection in Canada. From Quebec, 91 cases were reported mostly from and around Montreal. From Manitoba, 19 cases were reported from Winnipeg and surrounding areas. Heartworm was found most frequently in companion dogs over three years of age maintained mainly outdoors in rural areas. About 28% of the cases were observed with clinical signs of heartworm disease and 78% had a history of not having left Canada.

     

Heartworm in dogs in Canada in 1988

In late November 1988, 1581 small and mixed animal clinics and institutional veterinarians across Canada were sent a questionnaire in order to assess the status of Dirofilaria immitis in Canada in 1988, and 46% of them responded. Veterinarians reported that 181,577 dogs were blood-tested for heartworm disease and 367 dogs were found with D. immitis microfilariae. Another 60 dogs were amicrofilaremic but diagnosed with heartworm disease to give the total number of cases diagnosed in 1988 as 441 (0.24%).     

Heartworm in dogs in Canada in 1989

In late November 1989, 1732 clinics and institutional veterinarians were sent a questionnaire to assess the status of Dirofilaria immitis, and 51.7% responded. Of 247,716 dogs tested, 394 had D. immitis microfilariae and 51 were amicrofilaremic for a total of 445 cases and heartworm prevalence of 0.17%. Most (408) of these dogs had no preventive medication and the prevalence among dogs tested and unprotected was 1.01%. That prevalence was considerably higher in endemic areas. Thirty-seven dogs with heartworm had preventive medication. Heartworm was most frequent in companion dogs over three years of age maintained outdoors in rural areas. About 75% of the cases had never left Canada, 26% had clinical signs and 125 were not treated.

Heartworm was reported from British Columbia, Manitoba, Ontario, Quebec, Nova Scotia and Newfoundland, but 383 cases were in Ontario. South-western Ontario was the primary focus of infection. There were 33 cases in Quebec and 24 in Manitoba, mainly found in and around Metropolitan Montreal and Winnipeg respectively.

     

Heartworm in dogs in Canada in 1987

In late November 1987, 1246 institutional veterinarians and small and mixed animal clinics across Canada were sent a questionnaire in order to assess the status of Dirofilaria immitis in Canada in 1987, and 50% of them responded. Veterinarians reported that 165,428 dogs were blood tested for heartworm disease and 511 dogs were found with D. immitis microfilariae. Another 78 dogs were amicrofilaremic but diagnosed with heartworm disease to give the total number of cases diagnosed in 1987 as 589 (0.35%).     

Heartworm in dogs in Canada in 1986

In late December 1986, 1224 institutional veterinarians and small and mixed animal clinics across Canada were sent a questionnaire in order to assess the status of Dirofilaria immitis in Canada in 1986; 46% of them responded. Veterinarians reported that 150,989 dogs were blood-tested for microfilariae and 869 dogs were found with heartworm. Another 65 dogs were amicrofilaremic but diagnosed with heartworm disease and one was found with heartworm at necropsy to give the total number diagnosed in 1986 as 935 (0.62%).

Heartworm was reported from Manitoba, New Brunswick, Ontario and Quebec, but most (810) of the cases were from Ontario. South-western Ontario continued to be the primary focus of the infection in Canada. There were 103 cases reported from Quebec, mostly from and around Montreal, and 21 cases from Manitoba, from Winnipeg and surrounding areas. Heartworm was found most frequently in companion dogs over three years of age maintained mainly outdoors in rural areas. About 33% of the cases were observed with clinical signs of heartworm disease and 81% had a history of not having left Canada.