鸡免疫重组禽流感(H5+H7)二价灭活疫苗效果评价

为了掌握重组禽流感(H5+H7)二价灭活疫苗在鸡中的免疫效果,分别在东莞选取5个规模养殖场和14个镇(街)散养鸡免疫疫苗21天后,采集血清样品进行H5亚型和H7N9亚型禽流感病毒抗体检测,结果为H5亚型禽流感病毒(Re-8株)抗体阳性率为79.23%(683/862),H7N9亚型禽流感病毒抗体阳性率为64.15%(553/862)。结果表明,该疫苗在鸡群中能够产生比较好的应答,H5亚型禽流感病毒(Re-8株)抗体阳性率均能达到免疫规范要求的70%以上。H7N9亚型禽流感病毒抗体阳性率,在种鸡场和肉鸡场能到70%以上,但散养鸡抗体阳性率较低,有不能抵御野毒侵袭的风险,还需要进行二次免疫。     

饲料中添加构树叶对1～9周龄蛋鸡新城疫和H5N1亚型(Re-4株和Re-5株)禽流感抗体的影响

为了研究饲料中添加构树叶对1～9周龄蛋鸡新城疫和禽流感H5N1亚型(Re-4株和Re-5株)抗体的影响,试验测定了海兰灰雏鸡的新城疫和H5N1亚型(Re-4株和Re-5株)禽流感抗体效价。结果表明:在3～9周龄时,与对照组相比,添加1.5%和2.0%构树叶组新城疫抗体效价均有不同程度的提高。在4～9周龄时,与对照组相比,添加1.5%和2.0%构树叶组H5N1亚型(Re-4株和Re-5株)禽流感抗体水平均有不同程度的提高。     

不同厂家重组禽流感病毒三价灭活苗抗体水平调查报告

为了解黔南州2020年秋季不同厂家重组禽流感病毒三价灭活苗(H5N1Re-11+Re-12株和H7N9H7-Re,2株)免疫抗体水平情况,笔者在辖区12个县(市)的家禽随机采集血清样本2147份,应用ELISA方法对家禽H5亚型、H7亚型免疫抗体水平进行调查。调查结果显示,在受检的2147份血清中,H5亚型抗体合格率为96.6%、H7亚型抗体合格率为93.9%。2个疫苗厂家抗体合格率均高于国家规定的70%。结果表明,黔南州2020年秋季禽流感病毒三价灭活苗(H5N1Re-11+Re-12株和H7N9H7-Re,2株)免疫抗体水平状况较好,能有效控制高致病性禽流感疫情的发生和流行。     

Re-8株H5亚型禽流感灭活疫苗对野鸟源H5N8流感病毒的免疫保护性研究

为评估当前应用的Re-8株种毒相关禽流感灭活疫苗对野鸟源H5N8流感病毒的免疫预防效果,本研究将重组禽流感病毒(AIV)H5亚型Re-8株灭活疫苗(H5N1亚型,Re-8株)和重组AIV(H5+H7)灭活疫苗(H5N1Re-8株+H7N9 H7 Re-1株)分别以0.3 m L/只的剂量接种3周龄SPF鸡,免疫3周时进行HI抗体检测和攻毒试验。结果显示,上述2种疫苗免疫的SPF鸡血清中针对H5亚型Re-8株抗原的HI抗体均在8 log2以上,以105EID50的剂量、鼻腔感染途径攻击野鸟源H5N8病毒BHG/QH/2/16和BHG/Tibet/3/16后,所有免疫组鸡在14 d观察期内均全部健活,不排毒,而对照组鸡在攻毒后4 d内全部发病、死亡、排毒。现地免疫重组AIV H5亚型三价灭活疫苗(Re-6株+Re-7株+Re-8株)的商品蛋鸡直接进行HI抗体检测和攻毒试验,结果显示,免疫蛋鸡血清中针对Re-8株抗原的HI抗体平均滴度为8.3 log2,以相同攻毒方式和剂量分别攻击2株H5N8病毒后,免疫鸡也获得完全免疫保护,不发病、不死亡、不排毒。本研究结果表明,含有重组AIV H5 Re-8株抗原的灭活疫苗可有效防控野鸟源H5N8流感病毒,为我国及其他国家H5N8亚型禽流感免疫防控提供了科学依据。     

2014—2015年深圳野生鸟类禽流感流行病学监测

为调查深圳野生鸟类的禽流感感染情况,于2014年1月~2015年4月采集了678只野鸟的569份粪便,62份肛门拭子,26份咽肛拭子和21份血样.采用病原分离鉴定法、AIV-Ag(通用型)抗原速测卡胶体金法、荧光RT-PCR试验对样品拭子进行病原学检测.采用血凝抑制实验(HI)对血清样品进行H5N1(Re-4)、H5N1(Re-6)、H5N1(Re-7)、H7、H9等5种血清型AIV抗体检测.结果显示:26份咽肛拭子分离出1株H9N2亚型禽流感病毒,阳性率为3.85%;粪便和拭子样品的抗原检测全部阴性;血清样品中H5(Re-4)阳性数1份,阳性率为9.09%;H9阳性数7份,阳性率为63.64%;未检出H5(Re-6)、H5(Re-7)及H7阳性抗体.     

重组H5亚型禽流感病毒三价灭活疫苗免疫效果的评价

为了评价重组H5亚型禽流感病毒三价灭活疫苗的免疫效果,在2016年7月至2017年8月期间,对免疫重组H5亚型禽流感病毒三价灭活疫苗(H5N1,Re-6株+Re-7株+Re-8株)的家禽采集了1 999份血清样品,采用血凝与血凝抑制方法进行检测,结果为H5亚型禽流感病毒Re-6株免疫合格率为86.84%,H5亚型禽流感病毒Re-7株免疫合格率71.44%,H5亚型禽流感病毒Re-8株免疫合格率为67.78%。结果表明,免疫重组H5亚型禽流感病毒三价灭活疫苗后,不同毒株的抗体、不同种类的家禽、不同免疫次数的抗体水平均有差异。     

樱桃谷肉鸭免疫重组禽流感病毒(H5+H7)二价灭活疫苗血清抗体监测报告

为监测重组禽流感病毒(H5+H7)二价灭活疫苗(H5N1 Re-8株+H7N9 H7-Re1株)在樱桃谷肉鸭免疫效果,于2017年8~9月,对5个樱桃谷肉鸭养殖场开展了疫苗免疫与抗体检测试验。监测结果表明,35日龄时,有4个场的H5N1 Re-8禽流感亚型疫苗的平均抗体滴度高于4log2,3个场的抗体阳性率高于70%;H7N9禽流感亚型疫苗免疫后5个场的平均抗体滴度均高于4log2,抗体阳性率均高于70%。两个疫苗批次间免疫效果差异不显著(P0.05)。但生长前期禽流感H7N9亚型存在母源抗体空白期;生长中期,禽流感H5N1亚型存在抗体低谷阶段。均存在一定程度AIV感染风险。建议进一步加强疫苗应用监测与免疫程序研究,提醒养殖场户加强生物安全防控,防止疫病发生。需要进一步加强疫苗应用监测与技术指导,提醒养殖户加强生物安全防控,防止疫病发生。     

重组禽流感病毒灭活疫苗(H9N2亚型,Re-9株)对2010年～2011年流行病毒株免疫效力的研究

为评价H9N2亚型重组禽流感病毒(AIV)灭活疫苗Re-9株的免疫效力,本研究选取2010年～2011年分离的5株H9N2亚型AIV进行攻毒保护实验。这5个分离株均为类A/CK/Beijing/1/94病毒株,其HA和NA基因与Re-9株及其亲本株的同源性介于90.6%～97.5%和88.1%～98.7%之间,其抗原相关值在66.67%～100%之间。将Re-9株为种毒制备灭活疫苗,免疫4周龄SPF雏鸡后,3周时平均HI抗体效价达9.5 log2;在免疫后3周以2×107EID50的剂量攻击亲本株和5株流行病毒株,攻毒后采集3 d、5 d、7 d的拭子,免疫组拭子样品病毒检测均为阴性;对照组3 d、5 d拭子病毒检测的阳性率均在80%以上,7 d的阳性率在60%以下。以上结果表明灭活疫苗Re-9株抗原针对性强,而且具有良好的免疫效力,能够抵御近年来分离的H9N2亚型AIV,是理想的H9N2亚型禽流感疫苗株。     

重组禽流感H5+H7二价灭活疫苗的免疫效果评估与分析

为了客观评价重组禽流感H5+H7二价灭活疫苗(H5N1Re-8株+H7N9Re-1株)的免疫效果及当前禽流感免疫程序的合理性,提高本地区禽流感防控工作水平,采用血凝抑制试验(HI)和酶联免疫吸附试验(ELISA)对某养殖场免疫的100羽蛋鸡进行不同时间段H5、H7亚型禽流感抗体水平检测。结果:在免疫后21～252 d,HI和ELISA检测禽流感H5亚型抗体合格率均为74%～100%;禽流感H7亚型HI检测抗体合格率为78%～100%,ELISA检测抗体合格率为76%～100%。结果表明:HI与ELISA抗体检测结果基本相符,在免疫后21～252 d免疫抗体合格率均达到国家规定≥70%的要求,重组禽流感H5+H7二价灭活疫苗免疫效果良好。     

重组禽流感病毒H5+H7亚型三价灭活疫苗(H5N1 Re-11株、Re-12株+H7N9 Re-2株)对白羽肉鸡免疫抗体监测试验

为了评估重组禽流感病毒H5+H7亚型三价灭活疫苗(H5N1 Re-11株、Re-12株+H7N9 Re-2株)对白羽肉鸡免疫效果以及对白羽肉鸡最佳免疫时间,试验选取3个厂家(a、b、c厂)重组禽流感病毒H5+H7亚型三价灭活疫苗(H5N1 Re-11株、Re-12株+H7N9 Re-2株)分别在1日龄和7日龄进行接种,于接种前(1,7日龄)、14,21,28,35,42日龄采血进行抗体检测,以了解不同厂家高致病禽流感疫苗对白羽肉鸡免疫效果以及最佳免疫时间。结果表明:3个厂家高致病性禽流感疫苗对白羽肉鸡免疫效果没有明显差异,在21日龄后H5N1 Re-11、H5N1 Re-12、H7N9 Re-2抗体效价均在4 lb以上,各毒株抗体效价在28,35,42日龄时,1日龄抗体效价要高于7日龄,且a厂家疫苗产生的抗体效价要略高于b、c厂。说明1日龄免疫效果要好于7日龄,最佳免疫时间为1日龄。     

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.