首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献，搜索用时 31 毫秒
1.
The prevalence of Chlamydia psittaci infection in household, feral and farm cats in Britain was investigated. Chlamydia were isolated from 30 per cent of conjunctival swabs collected from 753 household cats with conjunctivitis. The prevalence of active chlamydial infection was highest in cats in the age group five weeks to nine months. Males were more frequently infected than females. Cats with chlamydial conjunctivitis usually had antibody titres greater than 1024 as assessed by indirect immunofluorescence. Chlamydia appeared to be endemic in two out of three feral cat colonies on the basis of serological evidence and occasional isolations. Cats on 10 of 22 sheep farms (45 per cent) had serological evidence of chlamydial infection, and this was confirmed on two farms by isolation of the organism from conjunctival and, or, rectal swabs. This is the first survey of infection with Chlamydia psittaci in cat populations in Britain.  相似文献   

2.
Brucellosis in sheep, caused by Brucella ovis, is primarily a chronic infectious disease of rams with epididymitis as its most characteristic lesion. Six hundred rams from an infected farm were clinically and serologically examined once a year, over a 3-year period. An increase from 2.1% to 6.3% in the prevalence of animals serologically positive to B. ovis occurred over the 3 years. However, the prevalence of rams with lesions in the reproductive tract declined from 14.2% to 6.5% in the third year following one year of strict culling of clinically affected and rams that were serologically positive for B. ovis. Clinical lesions found in the 179 affected rams fell into two main categories: rams with epididymitis and rams with affected lymph nodes. These results suggest that the prevalence of the disease relates mainly to the sexual activity of the animal and not to age in itself. A single cull based on the results of clinical examination and serological test results was unable to decrease the prevalence of B. ovis in an extensive Corriedale sheep flock.  相似文献   

3.
A cross-sectional serological survey was conducted in order to evaluate, irrespective of abortion, the Toxoplasma gondii infection in pastured sheep from the Campania region of southern Italy. A geographical information system was used in order to uniformly sample the ovine farms (n=117) throughout the entire region. Blood and milk samples were collected from 10 adult sheep (>18 months) on each farm (total number=1170 sheep). Serum samples were tested for the presence of IgG antibodies to T. gondii using a commercial indirect fluorescent antibody test. For each farm, the 10 milk samples collected were pooled in order to obtain a single milk sample per farm (total number=117 milk samples). The 77.8% (91/117) of the farms and the 28.5% (333/11,170) of the sheep resulted positive by serology. In addition, the presence of T. gondii DNA was detected by PCR in 4 milk samples out of the 117 examined (3.4%).  相似文献   

4.
AIM: To investigate the seroprevalence of Neospora caninum infection in populations of dogs from dairy farms, sheep/beef farms and urban areas in the central part of New Zealand. It was postulated seroprevalence would be higher for farm dogs than urban dogs if the life-cycle of this parasite involves transmission between dogs and cattle. METHODS: Serum samples were obtained from dogs that lived on dairy farms (n=161), sheep/beef farms (n=154) and in urban situations (n=150). The relative risk of detecting antibodies to N. caninum using an immunofluorescent antibody test (IFAT) was compared between farm and urban dogs. RESULTS: The relative risk of having a titre of > or = 1:200 to N. caninum was 2.43 (95% CI=1.88-3.14) for dairy-farm dogs and 3.16 (95% CI=2.48-4.02) for sheep/beef-farm dogs, compared with urban dogs. At this titre, which is currently used in New Zealand to indicate seropositivity, seroprevalence of N. caninum infection was 30.7% in urban dogs, 74.5% in dairy-farm dogs and 96.8% in sheep/beef-farm dogs. CONCLUSION: This observation is consistent with a cycling of this disease between cattle and dogs on farms in New Zealand and with higher exposure of dogs to N. caninum on farms than occurs in urban environments. The prevalence of antibodies in all three groups of dogs tested in this study (dairy-farm dogs, sheep/beef-farm dogs and urban dogs) is higher than has generally been reported elsewhere. New Zealand farm dogs have a higher serological prevalence of N. caninum infection than urban dogs. CLINICAL RELEVANCE: Management and disease control practices that break the life-cycle of transmission between cattle and dogs should assist in controlling cattle abortion due to N. caninum.  相似文献   

5.
A total of 124 blood samples were collected from 92 sheep and 32 goats from 21 randomly selected herds located in two regions of Greece. Data on the characteristics of the animals (species, gender, age, tick burden, presence of haemoglobinuria, prior treatment for babesiosis) and the herd (location, size, species of animals, dogs associated with the herds, tick burden of dogs associated with the herds) were collected through questionnaires. Nineteen animals (15%) produced the DNA fragment specific for Babesia of which 16 were sheep and three were goats. Nucleotide sequence of PCR products revealed 100% homology with Babesia ovis 18S rRNA gene. Nine farms (43%) were found positive for B. ovis. The percentage of positive animals in each farm varied between 10 and 61%. The relative risk of the presence of ticks in sheep and goats (p<0.01) and farm dogs (p<0.01) for PCR-positive results for B. ovis in sheep and goats was found 6.63 and 4.14, respectively.  相似文献   

6.
以隐孢子虫(Cryptosporidium spp.)18S rRNA为靶基因,通过巢氏PCR检测发现在采集的101份新鲜粪便样品中18份样本为阳性。不同地区羊场的隐孢子虫感染率分别为：李集镇36%(18/50),新安镇0%(0/30)、堆沟港镇0%(0/21)未检出隐孢子虫。但通过对4羊场的分析发现,有2个羊场(50%)为隐孢子虫感染阳性,且不同的羊场感染率差异显著,因此单纯的以地区来评价隐孢子虫的感染率,是值得商榷的。山羊隐孢子虫的感染率为33.3%,湖羊隐孢子虫的感染率为2%。2～6月龄的育肥羊隐孢子虫的感染率为36%,6～10月龄的育成羊(0%)。对检测为阳性的样品进行了隐孢子虫18S rRNA基因片段序列分析,发现18个样品全部为肖氏隐孢子虫(Cryptosporidium xiaoi),不存在泛在隐孢子虫(Cryptosporidium ubiquitum)。在检测隐孢子虫感染阳性的1个山羊场和1个羊湖羊场均存在肖氏隐孢子虫感染,不存在泛在隐孢子虫,更未发现肖氏隐孢子虫和泛在隐孢子虫的混合感染。目前的数据提示肖氏隐孢子虫对2～6月龄山羊(33.3%)和湖羊(2%)具有更高的...  相似文献   

7.
AIM: To investigate the seroprevalence of Neospora caninum infection in populations of dogs from dairy farms, sheep/beef farms and urban areas in the central part of New Zealand. It was postulated seroprevalence would be higher for farm dogs than urban dogs if the life-cycle of this parasite involves transmission between dogs and cattle.

METHODS: Serum samples were obtained from dogs that lived on dairy farms (n=161), sheep/beef farms (n=154) and in urban situations (n=150). The relative risk of detecting antibodies to N. caninum using an immunofluorescent antibody test (IFAT) was compared between farm and urban dogs.

RESULTS: The relative risk of having a titre of ≥1:200 to N. caninum was 2.43 (95% CI=1.88-3.14) for dairy-farm dogs and 3.16 (95% CI=2.48–4.02) for sheep/beef-farm dogs, compared with urban dogs. At this titre, which is currently used in New Zealand to indicate seropositivity, seroprevalence of N. caninum infection was 30.7% in urban dogs, 74.5% in dairy-farm dogs and 96.8% in sheep/beef-farm dogs.

CONCLUSION: This observation is consistent with a cycling of this disease between cattle and dogs on farms in New Zealand and with higher exposure of dogs to N. caninum on farms than occurs in urban environments. The prevalence of antibodies in all three groups of dogs tested in this study (dairy-farm dogs, sheep/beef-farm dogs and urban dogs) is higher than has generally been reported elsewhere. New Zealand farm dogs have a higher serological prevalence of N. caninum infection than urban dogs.

CLINICAL RELEVANCE: Management and disease control practices that break the life-cycle of transmission between cattle and dogs should assist in controlling cattle abortion due to N. caninum.  相似文献   

8.
Experimental ovine eperythrozoonosis was studied using Giemsa staining of blood films and a modified indirect immunofluorescent antibody assay (IFAA). The serums of 21 Border Leicester Merino cross lambs between 12 weeks and 7 months-of-age were analysed before and after infection with Eperythrozoon ovis (E. ovis) using the IFAA test. No rise in the IFAA titre was seen until day 7 and this coincided with the first detection of E. ovis organisms in blood smears stained with Giemsa. The percentage of E. ovis infected red blood cells peaked on day 14, but the IFAA titre did not peak until day 35. Titres to E. ovis, on average, had begun to drop by day 63. There was considerable individual variation in response to E. ovis infection as measured by the IFAA. Titres as high as 6,400 were observed in individual sheep at the peak of E. ovis parasitaemia of red cells. One sheep had a titre of 51,200 nineteen days after infection, and titres of 3,000 were maintained for several months in a few sheep. The assay proved reliable, and up to 100 samples per day could be tested. The antigenicity of the slide preparations was found to be satisfactory after storage for 6 months at -20 degrees C and 4 degrees C and for 28 months at -70 degrees C. Temperature fluctuations during storage rendered slides unsuitable for the IFAA after these times. A method of storing E. ovis infected blood in liquid nitrogen is described.  相似文献   

9.
为探究附红细胞体在内蒙古呼和浩特市托克托县地区的流行情况,接诊呼和浩特托县地区某东佛里生奶绵羊养殖场病例,该场近一周多圈舍出现产奶羊只体温升高、精神沉郁、瘫软、食欲减退或废绝等症状,有出现症状1 ~ 2 d迅速死亡病例,也有使用抗生素硫酸庆大霉素-青霉素联用结合补液治疗1周无好转或死亡病例,死亡总数超8只,仍有10余只相似症状正在接受治疗。经现场剖检、圈舍环境调查、样品实验室检测,结合临床诊疗,确诊此次疫情为奶绵羊附红细胞体病,且周边羊养殖场（户）羊只也存在附红细胞体感染。说明附红细胞体在托克托县呈地方性流行。  相似文献   

10.
Objective: To investigate control options for contagious ecthyma (scabby mouth) in Australian sheep exported live to the Middle East.
Design: Prevalence, vaccination and modelling studies.
Procedure: One hundred and forty weaner sheep (less than 1 year old) on each of 106 farms in Western Australia (WA) and 18 farm groups of adult wethers received at a WA commercial feedlot were examined for lesions of scabby mouth. Sheep on a total of 26 farms in 3 States were divided into treatment and control groups for the vaccination study. A simple deterministic compartmental model was developed to establish which parameters had the greater effect on disease prevalence.
Results: The proportion of farms with evidence of scabby mouth in weaner sheep was 23.6% and, on those farms with the disease, the overall prevalence was 6.1%. At the feedlot, 4 out of 18 farm groups had 5 or more sheep with lesions on arrival. The overall prevalence in the 4 diseased groups was 5.2%. Sheep vaccinated on farm before trucking to the feed-lot had a lower prevalence of scabby mouth at the end of simulated shipping than controls. The main determinant of scabby mouth prevalence was the proportion of sheep immune to the disease.
Conclusion: A program of vaccination for scabby mouth will reduce the prevalence of disease during live export. However, using current technology it is not possible to deliver shipments of sheep to the Middle East that are guaranteed completely free of scabby mouth.  相似文献   

11.
ABSTRACT

Aims: To determine whether sheep that co-grazed with cattle that were suspected to be positive for bovine viral diarrhoea (BVD) virus had serological evidence of exposure to the virus.

Methods: Eighteen commercial farms that routinely co-grazed cattle and sheep in the same paddocks were recruited through purposive sampling. The recruiting veterinarians identified nine farms with cattle herds that were known or highly suspected to be positive for BVD and nine farms that were considered to be free of BVD. Blood samples were taken from 15 ewes aged 1 year on each farm and samples were submitted to a commercial diagnostic laboratory to test for antibodies against pestiviruses using an ELISA. All samples that were positive were then tested using a virus neutralisation test (VNT)for antibodies against BVD virus.

Results: Of the 270 blood samples, 17 were positive for pestivirus antibodies by ELISA and these originated from two farms that were known or suspected to have BVD virus-positive cattle. None of the samples from the nine flocks co-grazed with cattle herds that were known or suspected to be BVD virus-negative were positive for pestivirus antibodies. Within the two positive farms, 2/15 samples from the first farm and 15/15 samples from the second farm were antibody-positive. When the 17 positive blood samples were submitted for VNT, all 15 samples from the second farm tested positive for BVD virus antibodies with the highest titre being 1:512.

Conclusions and clinical relevance: In this small sample of New Zealand sheep and beef farms with suspected BVD infection in cattle, there was evidence of pestivirus exposure in co-grazed sheep. Although we were unable to confirm the origin of the exposure in these sheep, these findings highlight that farmers who are trying to eradicate BVD from their cattle should be mindful that the infection may also be circulating in sheep, and both populations should be considered a possible risk to each other for generating transient and persistent infections. Further work is needed to estimate the true prevalence of New Zealand sheep flocks that are affected by BVD and the associated economic impacts.  相似文献   

12.
羊附红细胞体病PCR检测方法的建立   总被引：5，自引：0，他引：5  
根据羊附红细胞体的16S rRNA基因参考序列，设计1对特异性引物．建立了检测羊附红细胞体的PCR技术。用本方法从感染血样中特异扩增出1条预期大小为1169bp的片段。该方法灵敏、快速、特异性高．可用于羊附红细胞体病的早期快速诊断和流行病学调查。  相似文献   

13.
A cross-sectional epidemiologic study was conducted in order to detect the presence of and to estimate the seroprevalence of Oestrus ovis L. infection in flocks of sheep from the central region of the state of Yucatan, Mexico. The risk factors associated with disease were also identified. A sample size of 10 animals per farm was used to detect seropositive animals, considering a 30% prevalence and 95% confidence level. Blood samples of 689 sheep from 88 flocks were collected and a questionnaire with questions about the flock and the host was applied. The thin layer immune assay test was used. The risk factors were screened using logistic regression procedures. 77% of the flocks had at least one-positive animal with antibodies against O. ovis. The overall seroprevalence and standard error was 30.6 +/- 3.5%. Only flock size and sheep nose color showed association (P < 0.05) with the disease. The odds ratios for flocks with less than 11 and with 11 to 25 sheep, as related to herds with 25 or more sheep, were 0.74 and 1.73, respectively. Sheep with dark noses had a higher risk (OR = 1.46) compared with sheep having light noses (P < 0.05).  相似文献   

14.
There was an 8-fold increase in the national prevalence of Taenia ovis in dogs during the first decade of the New Zealand hydatid disease control program. The temporal patterns in the prevalence of T. ovis were similar in both rural working dogs and urban pet dogs, with the highest prevalence found in the sheep farming areas. The dramatic increase in the prevalence of T. ovis was a reflection of the change in source of food for many working dogs, from the traditional raw viscera to carcase meat of sheep, a change necessitated by hydatid disease control. Other factors influencing the rise in prevalence of T. ovis in rural dogs were investigated using stepwise multiple regression techniques. The results of the regression analyses suggested that the rate of increase in the prevalence of T. ovis was influenced by 4 major factors: Taenia hydatigena variables (initial prevalence and rate of progress in control), an ethnic variable (Maori proportion in local population), canine variables (numbers of dogs per farm and per owner), and animal husbandry variables (pasture type, sheep density and numbers of sheep per farm). The results were discussed in the light of present knowledge of the epidemiology and immunology of the taeniid cestodes.  相似文献   

15.
AIM: To identify environmental, management and animal risk factors associated with the occurrence and severity of disease attributed to Salmonella Brandenburg infection in sheep. METHODS: A retrospective case-control study was undertaken, and details of disease prevalence and farm management methods were collected from two affected regions in southern New Zealand. Associations between possible risk factors and disease attributed to S. Brandenburg were evaluated using odds ratios. A case-control approach was used to assess risk factors associated with outbreaks of disease at the farm level, using unaffected farms as controls. A separate analysis was then performed within affected farms only, to assess risk factors associated with increasing severity of disease. RESULTS: Data were collected from 405 farms containing a total of 1,170,737 ewes. Of the 177 case farms, 172 (97%) had diseased mixed-age ewes, 78 (45%) had diseased two-tooth ewes and eight (5%) had diseased hoggets. Increased odds of farms being affected with S. Brandenburg were reported for farms that strip-grazed sheep, and as total numbers of sheep increased. Reduced odds of being affected were associated with feeding crops, and hilly terrain on those farms not feeding crops. Within affected farms, increased severity of disease was associated with strip-grazing and feeding hay in TT flocks, and later removal of rams in MA flocks. Reduced severity of disease was associated with shearing or crutching after July, and vaccination of sheep against Salmonella spp. CONCLUSIONS: Salmonella Brandenburg occurred in flocks that reported using intensive farming methods and that maintained high numbers of sheep. CLINICAL RELEVANCE: Risk factors associated with the occurrence and severity of the disease due to S. Brandenburg have been identified. This information is necessary to identify preventative and control measures that may be effective in reducing the risk of disease.  相似文献   

16.
Despite indications of a considerable spread of Maedi-Visna among sheep flocks in Germany, prevalence studies of this important infection are hardly available. Prior to any health schemes and guidelines, knowledge about regional disease distribution is essential. Depending upon herd size, 70 farms were randomly selected, of which 41 cooperated. A total of 2229 blood samples were taken at random and serologically examined. For assessment of selected farm characteristics a questionnaire exercise was conducted at all farms involved. The average herd prevalence is 51.2%, the within-herd prevalence is 28,8%. In the unvariate analysis of risk factors, small (10-100 sheep) and large (> 250 sheep) farms are more MVV-affected than medium sized farms. The average stable and pasture space per sheep is larger at non-infected- compared to infected farms. Owners judgement on general herd health turns out to be better at non-infected compared to infected farms. Taking infected farms only, the risk of within-herd prevalence above 20% is significant higher in crossbred than in purebred flocks.  相似文献   

17.
The objectives of this study were to describe the serological prevalence of maedi-visna in a sample of Ontario sheep flocks, and to identify management and demographic variables that were associated with seroprevalence for maedi-visna. A sample of 103 sheep flocks in Ontario was randomly selected from those flocks participating in the Red Meat Plan. The owners of these flocks were surveyed regarding management procedures on their farms, and blood samples were taken from a random sample of ewes in each flock. At least one ewe tested serologically positive, based on the agar gel immuno-diffusion test, in 69.9% of the farms. Positive serological reactions occurred in 20.9% of the 3880 sheep tested. Flock demographics and farm management variables were considered in a multiple regression model, and several factors were positively associated with higher maedi-visna seroprevalence rates. These included the average age of the flock, the number of years the owner had been sheep farming, the practice of using foster ewes, the practice of allowing lambs to have contact with other ewes that are lambing, and the average pasture acreage per ewe.  相似文献   

18.
Humoral immune response of sheep to infection with Eperythrozoon ovis   总被引：3，自引：0，他引：3  
Circulating antibody was detected by an indirect fluorescent antibody test (IFAT) in the serum of sheep infected experimentally with Eperythrozoon ovis. Antibodies were first detected 15 to 32 days after infection with E ovis and titres peaked at 41 days. This antibody may be associated, at least in part, with protection against infection with E ovis since the initial increase in antibody titre coincided with a fall in the primary parasitaemia. A role for antibody is suggested further by the fact that the prepatent period of infection was prolonged by one day and the parasitaemia initially remained at low levels in infected sheep protected by passively transferred hyperimmune serum. Moreover, following primary infection, acquired immunity was manifest by a lack of parasitaemia following challenge infections while increased IFA titres were observed. No evidence of opsonic activity was observed in an in vitro erythrophagocytosis test in that neither mouse macrophages nor sheep monocytes phagocytosed E ovis infected or uninfected erythrocytes sensitised with hyperimmune serum.  相似文献   

19.
AIM: To determine the prevalence of the two most commonly diagnosed pathogenic Leptospira spp. serovars, Hardjobovis and Pomona, in sheep in a sheep-only abattoir in New Zealand, and to determine the prevalence of kidneys which were leptospire culture-positive collected from sheep seropositive or seronegative to the microscopic agglutination test (MAT). METHODS: A repeated cross-sectional observational study was conducted of serological and kidney culture prevalences of Leptospira borgpetersenii serovar Hardjobovis and Leptospira interrogans serovar Pomona. Lines of sheep and individual sheep were systematically randomly selected at a sheep-only abattoir during 18 May 2004 to November 2004 and 06 December 2004 to 14 June 2005. Additionally, a cross-sectional study examined prevalences in a purposively selected line of sheep from a flock with clinical evidence of an outbreak of leptospirosis. RESULTS: In the study population of 15,855 sheep of which 2,758 were sampled, 5.7 (95% CI=4.9-6.7)% were seropositive to one or both serovars; 44.2 (95% CI=34.6-54.2)% of 95 lines of sheep and 44.9 (95% CI=35.0-55.3)% of 89 farms showed serological evidence of infection. The serological prevalence of serovar Hardjobovis was significantly higher than that of serovar Pomona both at line (33% and 4%, respectively) and individual (5% and 1%, respectively) levels. A low but persistent seroprevalence of Hardjobovis throughout both years suggested low-level endemicity to this serovar, whereas Pomona infections appeared to be sporadic. Leptospires were isolated from kidneys of 8/37 (22%) Hardjobovis- and 1/6 (17%) Pomona-seropositive, and 5/499 (1%) seronegative animals. Of the animals purposively sampled from a farm with a clinical outbreak of leptospirosis, all kidneys from the 13 seropositive animals were culture-positive, indicating a high risk of exposure of meat workers in outbreak situations. Kidneys of MAT-seropositive sheep were 21.7 (95% CI=7.6-61.9) times more likely to test culture-positive than kidneys from animals with negative MAT titres. In general, the results indicated that 13/1,000 sheep slaughtered were potentially shedding leptospires. CONCLUSIONS: The study demonstrated the presence of a definite risk of occupational exposure of meat workers in a sheep-only slaughterhouse to the two most commonly diagnosed pathogenic Leptospira spp. serovars in New Zealand.  相似文献   

20.
绵羊肠道寄生虫感染情况调查   总被引：2，自引：1，他引：1  
为了解河南省绵羊肠道寄生虫感染情况,应用寄生虫常规检测方法对5个规模化养羊场共1265份粪样进行了寄生虫感染情况调查。结果显示,共检出虫卵和卵囊5类,其中原虫2类(球虫、隐孢子虫)、线虫2类（类圆线虫、鞭虫）、绦虫1类。本次调查中共发现1178份粪便样品为寄生虫阳性,寄生虫总感染率为93.12％(1178／1265),5个绵羊场的隐孢子虫平均感染率为3.10％,球虫平均感染率为88.94％,鞭虫平均感染率为10.83％,类圆线虫平均感染率为59.11％,绦虫平均感染率为43.96%。本次调查发现绵羊寄生虫混合感染现象比较严重,其中球虫、绦虫和类圆线虫混合感染的比例达到60.10％;绵羊寄生虫感染率呈现随着年龄的增长而减少的趋势。  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号