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1.
Brucella suis has been recognized as the major etiological agent of human brucellosis in areas free from Brucella melitensis infection. However, with changes in swine management, the occurrence of swine brucellosis has decreased as has the human incidence of B. suis infection. A swine brucellosis outbreak within a herd from Jaboticabal (S?o Paulo, Brazil) was detected in July 2006. The herd comprised approximately 300 sows and 1,500 finishing animals. Many sows within this herd experienced abortions, while others exhibited vaginal discharge; three sows suffered posterior paralysis. Among 271 sows, 254 (93.7%) tested positive for brucellosis by complement fixation, and among 62 randomly bled finishing animals, 17 (27.4%) also tested positive. The B. suis biovar 1 was cultured from 14 aborted fetuses and six sows. Brucella was identified using routine methods. Fourteen farm workers were tested using agglutination tests, with three workers showing evidence of Brucella antibody titers. A 39-year-old woman, who worked with maternal pigs and had direct contact with aborted fetuses, presented an agglutinating titer of 480?IU/mL and displayed clinical signs of infection. Our findings suggest that despite a reduction of swine brucellosis throughout Brazil, B. suis infection still occurs, thereby posing a zoonotic risk.  相似文献   

2.
Sera from 14,408 market sows from the Canadian domestic swine herd were tested for trichinellosis using an indirect-ELISA as a screening test and a competitive ELISA for confirmatory testing. Three sera (0.02%) gave low level reactions on the competitive ELISA. These reactions were considered nonspecific, and this designation was supported by data from previous and subsequent national surveys, in which serologic, trichinoscopic, and digestion test methodologies was used. This study provides additional evidence that Canada is free of trichinellosis in domestic swine.  相似文献   

3.
In this study, we conducted an investigation to determine the true prevalence of bovine and ovine brucellosis in central-eastern Tunisia. A total of 1134 veterinary samples taken from 130 ruminant herds were screened for brucellosis using IS711-based real-time PCR assay. Sera collected from the ruminants were tested using the Rose Bengal test and indirect enzyme-linked immunosorbent assay. Based on serological and molecular results, the true adjusted animal population level prevalence was 23.5 % in cattle, against 13.5 % in sheep. In addition, the true adjusted herd level prevalence of brucellosis was 55.6 % in cattle and 21.8 % in sheep. A statistically significant association was found between vaginal and milk shedding for ruminants. In addition, our results showed that Brucella abortus could be responsible for bovine and ovine brucellosis. Multivariable logistic regression analysis at the animal population level indicated that age and origin variables were important risk factors for cattle. However, age and abortion variables were found to be associated with ovine brucellosis. At the herd level, risk factors for Brucella positivity were as follows: abortion and herd composition for cattle against herd composition, mortality rates, and hygiene for sheep. Animal hygiene, food quality, and sanitary practices on the farm should be applied as strategies to control brucellosis in herds.  相似文献   

4.
Evidence of the status of trichinellosis in Canada's national swine herd is provided from data acquired through national surveillance programs and from a prevalence study of Trichinella in wild boar and domestic swine. More than 500,000 swine tested at abattoirs in ongoing animal health surveys since 1980 and 2 national swine serological surveys (1985 and 1990) showed no evidence of Trichinella infection, except for 3 occurrences in a small infected zone in Nova Scotia. The prevalence study of domestic swine and wild boar was conducted for the prevalence of Trichinella after an epidemiological investigation of a 1993 outbreak of human trichinellosis in Ontario showed that the disease was linked to the consumption of wild boar meat originating from 2 farms in the province. Sera and tissues were collected from 391 wild boar and 216 domestic swine originating from 228 farms in Quebec, Ontario, Manitoba and Saskatchewan. The survey examined approximately 37% of the wild boar slaughtered in Canada in 1994. A pepsin-HCl digestion test of the tissues and an ELISA performed on the sera did not yield any positive results. These findings and the lack of human cases of Trichinella from the consumption of Canadian pork for nearly 2 decades suggest that the parasite has been rare in domestic swine and wild boar raised in Canada. Trichinella spiralis has only been found sporadically in swine in a small region within Nova Scotia.  相似文献   

5.
An outbreak of brucellosis caused by Brucella abortus biovar 2 was identified in cattle in Alberta in December 1986. This was the only clinical infection discovered since the national cattle herd was declared brucellosisfree in 1985. It was the first report of B. abortus biovar 2 in Canadian cattle. The outbreak, involving three herds containing purebred Hereford cattle, was spread by the private treaty sale of untested cattle, and was identified following investigation of an abortion. The source of infection for the outbreak was not established, but several possibilities were identified including infected herds present in the area during the mid-1970's, latent infection originating in a Saskatchewan herd during the early 1960's, American cattle imported during the early 1970's, and brucellosis-infected bison in Wood Buffalo National Park. The containment and elimination of this nidus of infection appears to have been successful, and the national cattle herd at the time of writing is free of the disease.  相似文献   

6.
Serum samples from 458 swine from eight specific pathogen-free (SPF) herds swine were compared to samples from 178 swine from eight non-SPF herds in Illinois using the complement fixation (CF) test for Mycoplasma hyopneumoniae antibodies. In SPF herds, 9.4% of the samples gave positive test results, compared to 51.7% of the samples from non-SPF herds. The range of reactor rates in SPF herds was 0–26.9% and in non-SPF herds 3.4–100%. Used on herd basis with some modification, the CF test should be useful in monitoring state and nationally accredited SPF swine herds.  相似文献   

7.
An indirect enzyme-linked immunosorbent assay (ELISA) for the detection of Brucella abortus antibodies in bovine bulk milk samples was evaluated. About 31 individual milk samples from B. abortus infected cows were diluted into bulk milk from a brucellosis free herd. Individual milk samples obtained from 96 negative or positive herds to ELISA or Brucella ring test (BRT), were tested by ELISA. All positive cows were bled and serum samples were tested by the complement-fixation test (CFT) which was considered the definitive test. A herd was considered infected if at least, one cow was positive in the CFT. Four samples were negative in the BRT at the dilution 1:10 but positive in the ELISA. For samples positive in both tests, BRT titers ranged from 1:10 to 1:480 while ELISA titers ranged from 1:10 to 1:3200.Using bulk milk samples, the sensitivity of the ELISA (98.1%) was higher than the BRT (72.2%) but the specificity of BRT (90.5%) was not statistically different (P=1.0) from the ELISA (88.1%). The implications of the results for brucellosis control are discussed.  相似文献   

8.
Simple and rapid field tests for brucellosis in livestock   总被引：1，自引：0，他引：1  
Four simple and rapid field tests for the serodiagnosis of brucellosis in cattle, goat, sheep and swine were developed. The performance of the assays was investigated using serum samples collected in Portugal from animals originating from herds with a defined sanitary status with respect to the presence of brucellosis. The sensitivity calculated for the bovine, caprine, ovine and swine Brucella lateral flow assays based on results obtained for samples collected from animals with culture confirmed brucellosis was 90%, 100%, 90% and 73%, respectively. None of the samples from animals from herds free of brucellosis reacted in the flow assays indicating a high specificity. However, as expected, some degree of reactivity was observed when testing selected serum samples that reacted non-specific in reference tests for brucellosis.  相似文献   

9.
Non-reactor cows in a dairy herd and six beef herds quarantined because of brucellosis were vaccinated with Brucella abortus Strain 19 and tested by rivanol and complement-fixation (CF) tests. Cows with rivanol 100 and CF 80 test titers at 2 months post-vaccination (p.v.) were defined as test positives. In the dairy herd, 46 test positives were diagnosed as follows: 17 (37%) had field strain infection; 1 (2%) had a Strain 19 infection; an additional 18 (39%) were brucellosis reactors at 4 months p.v.; 10 (22%) had declining or negative serologic tests at 4 months p.v. In the beef herds, 58 test positives were diagnosed as follows: 19 (33%) had field strain infection; 5 (9%) had Strain 19 infection; an additional 21 (36%) were brucellosis reactors at 6 months p.v.; 13 (22%) had declining or negative serologic tests at 6 months p.v.

Since the majority of the test-positive cattle were diagnosed as either infected with B. abortus or brucellosis reactors, segregation of these cattle should reduce field strain exposure for the remaining cattle in the herd and therefore reduce the number of new cases of brucellosis.  相似文献   


10.
The use of an ELISA that can differentiate between swine infected with pseudorabies virus (PRV) and swine vaccinated with a specific PRV vaccine was evaluated on an individual and herd basis, and a system for interpreting ELISA results on a herd basis was developed. In 17 herds, recently introduced replacement gilts, seronegative for PRV, were vaccinated with a thymidine kinase- and glycoprotein X (gpX)-deleted vaccine. After vaccination, blood samples were collected from these gilts approximately every 1 to 2 months for up to 19 months. Serum samples were analyzed for antibodies to gpX antigen, using a commercially available ELISA kit according to the manufacturer's protocol. Herd status was determined as positive, suspect, or negative, according to the serum sample:negative control (S:N) values of the samples collected from the herd. From the 17 herds, 130 evaluations were performed. On 49 (38%) of the 130 herd evaluations, 1 or more gilts had suspect test results. Additional testing was required in 19 (39%) of these 49 herd evaluations to determine the PRV infection status of the herd. Status of herds having gilts with suspect results and no positive results was usually negative after retesting. Herds having gilts with positive results were unlikely to have negative status after retesting.  相似文献   

11.
Data on farm characteristics and the results of the first herd test for brucellosis were collected for 74 reactor and 74 negative herds in Wellington County, Ontario. Each reactor herd was classified as either probably infected or probably not infected using the occurrence of abortions prior to the first herd test or during the testing period, the total number of cattle removed and/or the spread of reactors within the herd as criteria of infection.  相似文献   

12.
黑龙江某养猪户仔猪零星发病死亡,经PCR诊断为亚临床猪瘟。采集了60头母猪血,采用间接ELISA试剂盒检测60头母猪猪瘟免疫抗体水平。结果表明,该户母猪猪瘟免疫抗体水平较低,免疫抗体合格率仅为3.3%。因此,母猪免疫失败是导致仔猪散发猪瘟的主要原因。  相似文献   

13.
The serum-neutralization test (SN), enzyme-linked immunosorbent assay (ELISA) and the radial immunodiffusion enzyme assay (RIDEA) were compared for the detection of pseudorabies (PRV) antibodies in swine sera. A total of 1285 serum samples were tested. All three tests were considered useful in determining the PRV antibody status of swine on a herd basis, but available evidence supports the continued use of SN as the definitive test because of possible false positive reactions associated with ELISA and RIDEA.  相似文献   

14.
We determined the prevalence of tuberculosis and brucellosis reactors in the dairy herds in the Mbarara district of Uganda in 2002. This is one of the most important dairy-production areas of the country and includes both pastoral and agro-pastoral zones. A total of 340 (of 11,995) randomly selected herds were tested for tuberculosis, using the intradermal tuberculosis-skin test and 315 (of 10,562) herds tested for brucellosis using the serum Rose Bengal test.

The herd prevalence for tuberculosis reactors was 74.1% (95% confidence intervals 69, 78), the individual-animal prevalence was of 6.0% (5.6, 6.5) and within-herd range was 1–50% (up to 100% if suspicious reactors were included).

The herd prevalence for brucellosis was 55.6% (50, 61.2) individual-animal prevalence 15.8% (14.8, 16.7) and within-herd range 1–90%.

The reactor prevalence increased with the age of the animals for both tuberculosis and brucellosis.

Tuberculosis reactor prevalences were higher in animals from the agro-pastoral zone. However, the individual-animal and herd prevalences of brucellosis seroprevalences were higher in the pastoral zone.  相似文献   


15.
From February 1983 to June 1985, 188 desert bighorn sheep (Ovis canadensis nelsoni, = 161 and Oc cremnobates, = 27) from 18 herds in 17 mountain ranges and one captive herd were caught, marked, and had blood, fecal, and nasal mucus samples collected. Nasal swab specimens were cultured bacteriologically and virologically specifically for parainfluenza-3 (PI-3) virus. Bacterial flora differed from herd to herd. Pathogenic pneumophilic bacteria (eg, Pasteurella sp) seldom were found. Parainfluenza-3 virus was isolated from 6 bighorn sheep in 3 herds. Fecal specimens were examined for parasite ova and low numbers of lungworm (Protostrongylus sp) larvae were found in feces from 2 herds. Sera were evaluated for antibodies against respiratory syncytial virus, ovine progressive pneumonia, infectious bovine rhinotracheitis, PI-3, bovine viral diarrhea, brucellosis, leptospirosis, contagious ecthyma, bluetongue, and epizootic hemorrhagic disease. Blood clots were cultured virologically for bluetongue and epizootic hemorrhagic disease. Serologic evidence of bluetongue and/or epizootic hemorrhagic disease was found in 9 herds, and bluetongue virus (serotypes 10,11,13 and 17) was isolated from 3 herds. Antibody titers against PI-3 and respiratory syncytial virus were found in 9 and 13 herds, respectively. Evidence of bovine viral diarrhea infection was found in 6 herds, whereas infectious bovine rhinotracheitis was found in only 1 herd. Antibody titers against contagious ecthyma were found in 9 of 18 herds in California, and active lesions were seen occasionally. Evidence of ovine progressive pneumonia, leptospirosis, or brucellosis was not found.  相似文献   

16.
Brucellosis in Ontario: a case control study.   总被引：1，自引：1，他引：0       下载免费PDF全文
Data from cattle herds infected with brucellosis and from control (noninfected) herds were collected and analyzed using case control techniques. It appeared that herds located close to other infected herds and those herds whose owners made frequent purchases of cattle had an increased risk of acquiring brucellosis, particularly those who made purchases from other herds or from cattle dealers. Infected herds had a lower level of vaccination than noninfected herds. However, the percentage vaccinated was highly variable in each group. Vaccination per se did not appear to adversely influence the interpretation of serological test results nor did it appear to protect the individual animal. Once infected, the time required to become free of brucellosis was increased by large herd size and/or loose housing. Closed herds also took longer to become brucellosis free than more open herds. The percentage of animals removed from the herd was increased by active abortion. Those herds with multiple serological reactors (positives and questionables) at the first herd test after the imposition of quarantine had the highest percentage of cattle removed.  相似文献   

17.

Using a cross-sectional survey, we determined the prevalence and risk factors associated with bovine brucellosis in herds under extensive production system in southwestern Nigeria. Antibodies to Brucella species in serum samples were tested using the Rose Bengal test (RBT) and competitive enzyme-linked immunosorbent assay (cELISA); for milk, the milk ring test (MRT) and indirect-ELISA (i-ELISA) were used. Questionnaire was administered to cattle herdsmen to determine factors predisposing the animals to bovine brucellosis. Data were analyzed using STATA 12. From 513 serum and 635 milk samples tested among 120 herds, overall animal-level prevalence of 10.1% (95% CI 7.5–12.7%) and 20.2% (95% CI 17.1–23.3%) were recorded by RBT and MRT, respectively; while 9.4% (95% CI 6.9–11.9%) and 17.8% (95% CI 14.8–20.8%) were obtained using cELISA and i-ELISA, respectively. In all, from the 120 herds tested, 29.2% and 43.3% were positive by RBT and MRT, respectively. Multivariable logistic regression revealed that herd location (OR?=?8.12, 95% CI 1.68–38.90) and improper disposal of placenta/fetus (OR?=?17.33, 95% CI 4.81–62.33) were predictors for a seropositive herd using RBT; while herd location (OR?=?5.13, 95% CI 1.27–20.28), large herd size (OR?=?2.62, 95% CI 1.15–5.85), and occurrence of abortion for a year or more (OR?=?4.62, 95% CI 1.53–13.71) were predictors of seropositivity to antibodies to Brucella spp. using MRT. We found high prevalence of brucellosis in cattle herds under extensive management system in southwestern Nigeria. Urgent and coordinated control strategies are required to mitigate this problem.

  相似文献   

18.
An enzyme-linked immunosorbent assay was developed using a heat-killed Brucella suis antigen for detecting antibodies in the sera of swine from which B. suis was isolated. Optimal enzyme-linked immunosorbent assay reactions were obtained using heat-killed B. suis antigen at a concentration comparable to McFarland Standard No. 1. Statistically significant differences were observed in the enzyme-linked immunosorbent assay results of 40 animals from which B. suis was isolated and the results for 48 noninfected swine at serum dilutions of 1:25 and 1:50 (P < 0.0001). The enzyme-linked immunosorbent assay is a rapid reproducible test which can be readily automated that appears to have practical value for screening large numbers of breeding and slaughter swine for brucellosis.  相似文献   

19.
We developed log-linear and logistic-modeling approaches to investigate dependence among diagnostic tests. To illustrate the approaches, we used published data for swine toxoplasmosis, bovine paratuberculosis, and swine brucellosis. These diseases were selected because each animal's true disease status was known, at least five tests were used, and the serologic tests had been previously shown to have moderate-to-high pairwise dependence in test sensitivities (and sometimes in test specificities). Log-linear and logistic modeling yielded similar results for swine toxoplasmosis and swine brucellosis. However, logistic modeling could not be used to investigate test dependence for bovine paratuberculosis because of quasi-separation in the data attributable to two fecal-based tests having specificities of 100%. Findings from our modeling indicated that 3 (modified agglutination, enzyme-linked immunosorbent assay (ELISA), latex agglutination) of 5 serologic tests for toxoplasmosis and 2 (rivanol and particle concentration fluorescence immunoassay) of 6 serologic tests for brucellosis were adequate for diagnosis. For bovine paratuberculosis, both fecal-based tests (Herrold's egg-yolk culture and radiometric culture) and 1 (ELISA) of 3 serologic tests were necessary in serial and parallel testing schemes.  相似文献   

20.
An indirect ELISA test was developed as a novel tool aimed at monitoring the herd infection status of swine herds. Meat juice samples from pig carcasses were analysed for the presence of antibodies against porcine reproductive and respiratory syndrome virus (PRRSV). A study of samples from herds with known PRRS status was undertaken. The PRRS status of the herds was evaluated based on the analysis of blood samples by another serological test (blocking ELISA) capable of differentiating between infection with PRRSV of the American type and European type. The specificity of the indirect ELISA test on meat juice samples was 0.98. The sensitivity of the test depended on the type of the PRRSV strain involved. The apparent prevalence in herds infected with the American type of PRRSV was 0.44. The apparent prevalence in herds infected with the European type of PRRSV was 0.64. Herd level sampling and herd level criteria for assessing the PRRS status of herds by the new test were developed. Herds were classified as PRRS negative or PRRS seropositive based on 10 meat juice samples collected randomly at slaughter throughout a 3-month-period. Herd PRRS status classification by the indirect ELISA was validated in 47 herds by collection of blood samples from the herds. Eighteen herds were classified as PRRS negative by both test systems. Twenty-nine herds were classified as PRRS seropositive by both test systems. Acceptable herd classification was achieved using this test.  相似文献   

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