猪圆环病毒病的血清学调查

猪圆环病毒病是猪圆病毒(圆环病毒科)引起的一种新型传染病,病毒抵抗力较强,不易被灭活,可长时间存活,该病毒分为PCV-1和PCV-2两型,PCV-1型无致病性,该病主要由PCV-2型引起,病主要感染8-     

玉溪市猪圆环病毒2型流行情况调查

为了解玉溪市猪圆环病毒2型流行情况,于2015—2017年在玉溪市7县2区开展了猪圆环病流行病学调查,涉及105个乡(镇),255个村,规模场8个,散养户557户,采集猪脾肺组织样品917份,采用PCR方法进行PCV-2病原检测。结果显示:全市PCV-2病毒核酸阳性52份,阳性率5. 67%;规模场PCV-2病毒核酸阳性1份,阳性率为0. 74%;散养户PCV-2病毒核酸阳性51份,阳性率为6. 52%。表明该病在玉溪普遍存在,但各县区流行情况有所差别。     

华南地区猪圆环病毒和猪繁殖与呼吸综合征病毒检测分析

为了解华南地区猪圆环病毒及猪繁殖与呼吸综合征病毒的最新流行情况,采集了华南地区11个规模猪场各饲养阶段猪血清807份,用套式PCR(nPCR)检测猪圆环病毒1型(PCV-1)和猪圆环病毒2型(PCV-2);采集了若干猪场2010年1月至2011年8月期间有咳嗽、喘气、消瘦及疑似PDNS等临床症状的猪血清312份,以及无临床症状猪血清104份,以nPCR检测PCV-2,以一步法反转录PCR(RT-PCR)检测猪繁殖与呼吸综合征病毒。结果发现,所调查的11个规模猪场中只有5个检出PCV-1,所有猪场均检出PCV-2。PCV-2阳性率为30.61%,而PCV-1阳性率仅为4.21%;经产母猪和7周龄以上保育猪PCV阳性率最高;有临床症状的猪血清PCV-2阳性率为58.65%,PRRSV阳性率为37.82%,PCV-2阳性猪群中有39.89%的猪同时感染PRRSV;有症状猪群7月～9月的PCV-2感染率最高,而1月～3月最低;无临床症状猪血清PCV-2阳性率为27.9%,PRRSV阳性率为0.96%,PCV-2与PRRSV无混合感染。证明PCV尤其是PCV-2在华南地区仍广泛传播并流行,而且PCV-2与PRRSV混合感染致病情况较多。PCV-2的感染率与季节有一定的相关性,种猪带毒情况严重。     

猪断奶后多系统衰竭综合征防治探讨

猪断奶后多系统衰竭综合征(PMWS)是由猪2型圆环病毒(PCV-2)引起的一种造成断奶仔猪高死亡率的传染病。病猪的特征为逐步消瘦,皮肤苍白,呼吸急促,并继发感染其他疾病。该病现已在全国普遍发生,是造成养猪业经济损失的主要原因,应引起有关部门的研究和重视。1病原据国内外研究资料显示,PMWS的主要致病因子为猪圆环病毒2型,于1974年首次在猪肾传代细胞(PK-15)污染物中分离到PCV。1982年被命名为猪圆环病毒,为圆环病毒科圆环病毒属成员,单股环状DNA病毒,为已知的最小动物病毒之一。资料表明,PMWS可能是PCV-2与猪瘟、猪细小病毒、猪繁…     

猪圆环病毒基因及其疫苗的研究进展

猪圆环病毒(PCV)感染是近几年新发现的一种猪的传染病,目前,国际上已分离获得2个不同血清型的猪圆环病毒(PCV),并命名为猪圆环病毒1型(PCV-1)和猪圆环病毒2型(PCV-2).PCV-1对猪无致病性,而PCV-2被认为是引起断奶仔猪多系统衰竭综合征(PMWS)的主要病原.该病在包括中国在内的各养猪国家广泛流行,发病猪死亡率10%～30%不等,较严重的猪场在暴发本病时死淘率高达40%,给养猪业造成严重的经济损失,同时也给各国科研人员带来了新的挑战和任务,现已受到国内外学者的高度重视,对此病的研究特别是对其疫苗的研究正日益受到关注.文章中就猪圆环病毒基因的结构特点、功能以及疫苗等方面进行了综述,以期为猪圆环病毒基因及其疫苗的研究提供一定依据.     

华南地区猪圆环病毒1型与2型感染情况调查及相互关系

根据已发表的猪圆环病毒1型(PCV-1)与猪圆环病毒2型(PCV-2)的全基因组序列,设计4对特异性引物,用套式PCR方法对广东地区的规模养猪场或个体养殖户送检的144份猪血清进行了PCV-1与PCV-2病毒检测.结果显示PCV-1阳性血清21份,PCV-2阳性血清40份,PCV-1与PCV-2均为阳性的血清7份,PCV-1阳性率为14.6%,PCV-2阳性率为27.8%;PCV-1与PCV-2均为阳性的阳性率为4.9%,从数据上的比较可知PCV-2的感染率高于PCV-1的感染率.说明PCV-2感染比较普遍,患病猪群中也存在一定比例的PCV-1病毒感染.     

猪圆环病毒病临床症状和剖检变化

圆环病毒（PCV）最早于1974年在德国发现，为一种新的单链环状DNA病毒．后来发现该病毒分为PCV-1和PCV-2。早期研究认为PCV-1对猪无致病性，但在1991年加拿大最早发现致病性圆环病毒PCV-2。该病是由圆环病毒2型（PCV-2）引起的一种新的病毒病。近几年本病在世界许多国家包括我国广泛流行，给养猪业造成重大损失。受到各国的普遍关注。本病以皮肤苍白、腹泻、呼吸困难、渐进性消瘦为特征。     

猪圆环病毒疫苗的临床应用

猪圆环病毒病是近年新出现的一种病毒性传染病,严重影响猪群健康程度,威胁到生猪的免疫系统。该病是由猪圆环病毒(PCV)感染引起的,圆环病毒是目前发现最小的一种病毒,有3个血清型,即PCV-1、PCV-2和PCV-3。PCV-1为非致病性病毒。     

浅谈猪圆环病毒2型（PCV-2）

PCV-2是近几年来一种新发现的病毒,它所致疾病能给养猪业带来很大的经济损失。 PCV为圆环病毒科圆环病毒属成员,单股环状DNA病毒。PCV存在两种血清型,即PCV-1(猪圆环病毒1型)和PCV-2(猪圆环病毒2型)。PCV-1经常存在于机体各组织器官和某些传代细胞中,不致病。PCV-2则是引起PMWS(猪断奶后多系统衰竭综合征)的主要病原。据发现,单     

猪圆环病毒病的危害性及其防治措施

1猪圆环病毒病的危害性表现自1991年首次报道猪圆环病毒(PCV-2)病在我国存在以来,该病已在全国各地猪场迅速蔓延。据不完全统计,目前我国猪场的PCV-2抗体阳性率平均达42.9%,个别地区的猪场感染率可达80%以上,给养殖业造成巨大的经济损失。该病在临床上对猪的危害性主要有3个方面:第一,PCV-2本身可导致不同日龄猪出现相应的不同病症(如断乳仔猪衰竭综合征、皮炎-肾病综合征、母猪繁殖障碍、生长育肥猪的呼吸道综合征等)。第二,PCV-2可继发和并发多种传染病(如附红细胞体病、副猪嗜血杆菌     

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.