A method to identify BSE suspects in emergency slaughtered cattle during ante mortem examination

A method is presented by which a maximal number of BSE-infected cattle that had escaped the filter of clinical examination are identified during ante mortem examination. This approach might prove to be an efficient and cost-effective method for veterinary and non-veterinary meat inspectors to remove infected animals prior to slaughter. In a case-control study, the clinical signs of 224 randomly selected sick slaughtered animals were compared with the clinical signs of 26 sick slaughtered animals in which BSE infection was diagnosed using a rapid test post mortem. In addition, the clinical signs of the sick slaughtered BSE-positive animals were compared with the clinical signs of a group of BSE suspects identified during the same time period and in which BSE infection could be confirmed. As a result of this study a mathematical model was developed to identify BSE suspects. This model contains a total of 7 variables (clinical signs) that proved to be of importance. These signs were aggressive behaviour, grinding of teeth, protruding eyeballs, reduced rumination, inability to stand, overexcitability, and difficulty in standing up. The presented model has a sensitivity of 61.5% (16 out of 26 BSE-positive animals slaughtered while sick were identified) and a specificity of 99.6% when compared to a rapid test conducted post mortem.     

Microbiological differences between cull cattle slaughtered at an abattoir and cull cattle slaughtered on farms

Tissue samples from 27 casualty adult dairy cattle slaughtered on farms and 32 'normal' cull dairy cattle were analysed microbiologically for total viable counts (tvc), Enterobacteriaceae, Escherichia coli o157, Salmonella enterica and Campylobacter species. Overall the counts of Enterobacteriaceae and tvc were higher in the animals slaughtered on farms, particularly in the spleen. One 'normal' animal yielded E coli O157, and one yielded Campylobacter jejuni, and eight of the cattle slaughtered on farms yielded C jejuni and five yielded S enterica.     

Disposal of animal byproducts,dead and slaughtered animals

The current state of epidemiological knowledge about BSE clearly indicates that certain practices in carcass rendering had a significant impact on maintenance and spreading of BSE in the cattle population. This awareness did not come up spontaneously. As a reflection community legislation continuously developed and still does. The decisive move was done in the year 2000 by eliminating ruminant tissues with a high infectious potential with regard to BSE (specified risk material--SRM) from the human and animal feed chains. This step as well as the subsequent feed ban for all farm animals dramatically changed the logistical as well as the economical preconditions of the rendering industry. In fact the basic treatment (pressure cooking) remained almost unchanged. But instead of physically recycling the products they are nowadays predominantly used as an energy source in industry. In case of products that originate from the treatment of SRM burning is mandatory. These changes require a well adapted and intensified official supervision.     

Prevalence of Toxoplasma infection in cattle slaughtered at an Ohio abattoir.

Specimens of heart, diaphragm and, in 159 instances, esophagus were taken from 352 cattle slaughtered in an Ohio abattoir. The total weight of the material was 32 kg, and this was fed to 12 specific-pathogen-free cats to test for Toxoplasma infectivity. None of the 12 cats acquired Toxoplasma infection, as evidenced by their failure to excrete oocysts or to develop antibodies, and by failure to isolate Toxoplasma from their tissues by inoculation into mice. In further tests, a 650-g sample of beef from 77 of the 352 cattle was digested in 1% trypsin, then inoculated intraperitoneally into 40 mice. Toxoplasma was not isolated from the mice. Serums from 186 of the 352 cattle were inactivated at 60 C for 1 hour, then examined by the Sabin-Feldman (dye) test for antibodies to Toxoplasma. None had titers of more than 1:8. Of the 186 serums, 77 were also examined for antibodies in the indirect hemagglutination test. One had a titer of 1:64, which was considered nonspecific. Thus, evidence for Toxoplasma infection was not found in 352 cattle.     

Prevalence of Campylobacter spp. in slaughtered cattle and buffaloes in Vientiane, Lao People's Democratic Republic

This is the first report regarding isolation of Campylobacter in caecum and bile samples obtained from ruminants in Vientiane, Lao PDR. Campylobacter was isolated from 3 (1.6%) of the 184 caecum samples and 1 (1.0%) of the 100 bile samples obtained from buffaloes. Three of the 4 isolates were determined to be C. jejuni, which was detected in 2 caecum samples and 1 bile sample; the other caecum sample contained C. fetus. Campylobacter was not isolated from any of the 82 cattle caecum samples. Our results suggest that cattle and buffaloes may not be important sources of Campylobacter food poisoning in Lao PDR.     

Prevalence of Cryptosporidium, Giardia and Eimeria infections in post-weaned and adult cattle on three Maryland farms

The prevalence of Cryptosporidium, Giardia and Eimeria, in healthy, asymptomatic, post-weaned and mature cattle was investigated on three Maryland farms. One farm, a dairy research facility, had 150 multiparous Holstein milking cows; 24 were examined and Cryptosporidium andersoni was detected in three (12.5%) but neither Giardia nor Eimeria was detected. The second farm, a commercial dairy, had 57 multiparous Holstein milking cows and an equal number of heifers. Of 19 cows examined, C. parvum, Giardia duodenalis, and Eimeria bovis and/or E. ellipsoidalis were detected in two (10.5%), two (10.5%) and one (5.26%) cow, respectively. Of 23 heifers examined, C. parvum, Giardia, and E. bovis and E. ellipsoidalis, was detected in two (8.7%), four (17.4%), and five (21.7%), heifers, respectively. The third farm, a beef cattle breeding and genetics research facility, had 180 7- to 9-month old purebred black Angus. Of 118 examined for C. parvum and Giardia, 34 (28.8%) and 44 (37.3%) were positive, respectively, of 97 examined for E. bovis and/or E. ellipsoidalis 32 (33.0%) were positive. These findings, based on a method with a minimum detection level of 100 oocysts of C. parvum/g of feces, which underestimates the number of infected cattle, clearly demonstrate the presence of low level, asymptomatic infections in post-weaned and adult cattle in the United States and indicate the potential role of such cattle as reservoirs of infectious parasites.     

Geographical association between the genotype of bovine tuberculosis in found dead badgers and in cattle herds

In a survey, 457 badgers that had been found dead in Wales were postmortem-examined, and samples were examined by histology and by extended culture (for up to 12 weeks). Mycobacterium bovis was cultured from 55 badgers (12.0 per cent), and the histology typical of M bovis infection was seen in a further six (1.3 per cent). The prevalence in badgers in each of 10 geographical areas varied between 0 and 26 per cent (P<0.001), and was associated with the incidence of confirmed M bovis infection in cattle herds in the same areas (P<0.01). In northern Wales, bTB was rare in both hosts. An infected badger was 12.3 times more likely to be within 5 km of a confirmed cattle bTB breakdown than an uninfected badger. The M bovis isolates from badgers belonged to one of four genotypes defined by spoligotype and variable number tandem repeat type. These genotypes were also found in 290 concurrent confirmed herd breakdowns, and tended to be similar to the genotypes in badgers in the same geographical areas. When badgers and cattle no more than 30 km apart were compared, the genotype diversity was greater in cattle than in badgers (P=0.016), suggesting that the movement of cattle plays a greater part in the spatial distribution of M bovis than the movement of badgers.     

广西2000-2002年度炭疽流行概况及防制对策

炭疽 ( Anthrax)是由炭疽杆菌 ( Bacillus an-thracis)引起的一种人兽共患烈性传染病 ,易感动物主要是牛、马、羊、驴等草食动物。人类主要是由于接触患病牲畜 ,进食感染病畜肉尸、吸入含有该菌的气溶胶或尘埃、接触污染的毛皮等而罹患本病。由于炭疽杆菌在有充足的氧气和适当的温度 ( 2 5～ 30℃ )下能形成对外界环境具有极强抵抗力的芽孢 ,故能造成外界环境长期、广泛的污染 ,危害极大。广西是炭疽老疫区和高发省区之一 ,历年均有牲畜炭疽和人间炭疽发生。现将其 2 0 0 0— 2 0 0 2年 3年间的炭疽流行情况及防制对策概述如下。1　流行概…     

Prevalence and molecular characterization of Cryptosporidium spp. in dairy cattle from farms in China

Fecal samples of 2,056 dairy cattle from 14 farms were collected in three geographical regions of China and stained using a modified acid-fast staining technique to identify Cryptosporidium oocysts. A total of 387 (18.82%) positive samples were identified and further analyzed by polymerase chain reaction (PCR) using primers designed to amplify DNA fragments from the small subunit ribosomal RNA. The PCR products were sequenced and the sequences were deposited in the GenBank database under accession numbers EU369377-84 and GU070730-33. Phylogenetic analysis was performed and a distances matrix generated from these sequences confirmed the existence of Cryptosporidium (C.) parvum ''mouse'' genotype, C. bovis, C. andersoni, C. hominis, and C. serpentis in cattle. These results represent the first report on the prevalence and genetic identification of Cryptosporidium species, and may contribute to a better understanding of the epidemiology of Cryptosporidium in cattle in China.     

Prevalence of anthelmintic resistance on 62 beef cattle farms in the North Island of New Zealand

AIM: To establish the prevalence of anthelmintic resistance in parasitic nematodes on a random sample of beef cattle herds in the North Island of New Zealand. METHODS: A cross-sectional prevalence study was conducted using a standardised faecal nematode egg count (FEC) reduction (FECR) test (FECRT) for ivermectin, levamisole and albendazole on 60 calves on each of 62 farms in the North Island chosen at random from farms that conformed with the selection criteria. Resistance to an anthelmintic was inferred when there was <95% reduction in FEC 7-10 days after treatment. Larval cultures were performed for all control groups and for treated groups for which resistance was evident. RESULTS: Of the farms that completed the FECRT, 4/61 (7%) showed > or =95% reduction in FEC for all anthelmintics tested. Resistance to ivermectin was evident on 56/61 (92%) farms, to albendazole on 47/62 (76%) farms, and to both ivermectin and albendazole on 45/61 (74%) farms. Resistance to levamisole was evident on only 4/62 (6%) farms. The parasites most prevalent in resistant populations cultured were Cooperia spp. On 45/61 (74%) farms where Cooperia spp were present in sufficient numbers, resistance to both ivermectin and albendazole was evident. No cases of levamisole-resistant Cooperia spp were detected. Resistance of Ostertagia spp to ivermectin was evident on 4/45 (9%) farms, to albendazole on 15/46 (35%) farms, and to levamisole on 4/46 (9%) farms. CONCLUSION: Anthelmintic resistance in parasitic nematodes of cattle is common in the North Island of New Zealand. Beef farmers need to be aware of the risks posed by anthelmintic resistance, and routine FECR testing is recommended to ensure optimal productivity and to guide decision-making when purchasing anthelmintics to be used on-farm.     

Prevalence of anthelmintic resistance on 62 beef cattle farms in the North Island of New Zealand

AIM: To establish the prevalence of anthelmintic resistance in parasitic nematodes on a random sample of beef cattle herds in the North Island of New Zealand.

METHODS: A cross-sectional prevalence study was conducted using a standardised faecal nematode egg count (FEC) reduction (FECR) test (FECRT) for ivermectin, levamisole and albendazole on 60 calves on each of 62 farms in the North Island chosen at random from farms that conformed with the selection criteria. Resistance to an anthelmintic was inferred when there was <95% reduction in FEC 7-10 days after treatment. Larval cultures were performed for all control groups and for treated groups for which resistance was evident.

RESULTS: Of the farms that completed the FECRT, 4/61 (7%) showed ≥95% reduction in FEC for all anthelmintics tested. Resistance to ivermectin was evident on 56/61 (92%) farms, to albendazole on 47/62 (76%) farms, and to both ivermectin and albendazole on 45/61 (74%) farms. Resistance to levamisole was evident on only 4/62 (6%) farms. The parasites most prevalent in resistant populations cultured were Cooperia spp. On 45/61 (74%) farms where Cooperia spp were present in suffi cient numbers, resistance to both ivermectin and albendazole was evident. No cases of levamisole-resistant Cooperia spp were detected. Resistance of Ostertagia spp to ivermectin was evident on 4/45 (9%) farms, to albendazole on 15/46 (35%) farms, and to levamisole on 4/46 (9%) farms.

CONCLUSION: Anthelmintic resistance in parasitic nematodes of cattle is common in the North Island of New Zealand. Beef farmers need to be aware of the risks posed by anthelmintic resistance, and routine FECR testing is recommended to ensure optimal productivity and to guide decision-making when purchasing anthelmintics to be used on-farm.     

Clinical examination of cattle for BSE in a cattle facility and slaughterhouse

Detection of a case of BSE in slaughtered cattle causes considerable expenses. It seems therefore desirable to screen cattle before slaughtering and exclude suspect animals from slaughter. The object of this study was to determine the practicability of such screening under realistic conditions in a large slaughterhouse and to evaluate the specificity of the tests proposed by BRAUN et al. (1997). 949 cattle over 24 months old were examined in the Munich slaughterhouse. Spontaneous behaviour and the reaction to tactile, acoustic, and optical stimuli only could be tested. The evaluation of locomotion was not possible without interference with the routine processing of cattle before slaughter. The examination took about three minutes per animal. The results were evaluated using a modification of the scheme of BRAUN et al. (1997). The specificity of the classification "BSE very likely" was 97.8%. If all animals that exhibit any signs suggestive of BSE were to be excluded, the specificity would drop to 63.7%. This pre-slaughter clinical screening is not useful.     

Prevalence and genotypes of Giardia duodenalis in dairy and beef cattle in farms around Charlottetown, Prince Edward Island, Canada

Prevalence of Giardia duodenalis in dairy and beef cattle on farms around Charlottetown, Prince Edward Island (Canada) was determined by analyzing feces using direct immunofluorescence antibody microscopy. Genotypes were determined by 16S-rRNA sequencing. Fecal samples (n = 892) were collected from adult cattle in dairy tie-stall, dairy free-stall, and beef herds (10 herds each), and from calves (n = 183) from 11 dairy farms. Prevalence rates were 38% and 51% in cows and calves, respectively. Giardia duodenalis was present in all dairy herds, in 9/10 beef herds and in calves from 10/11 herds examined. Prevalence rates were 40% and 41% for cows in tie- and free-stall herds, respectively, and 27% for beef cows. Zoonotic Assemblage A was found in 12.2% of calves concomitantly infected with Assemblage E. All successfully sequenced samples (114/128) from cows corresponded to Assemblage E. Giardia duodenalis is highly prevalent in cattle herds in Prince Edward Island and Assemblage A in calves is a potential public health concern.     

Targeted surveillance to assess the prevalence of BSE in high-risk populations in western France and the associated risk factors

A pilot study was set up for the first time in France in August 2000, to obtain more precise estimates on the BSE epidemic in France. Three categories of cattle at risk of BSE (found dead on-farm, euthanased and emergency slaughtered) were sampled exhaustively from August 7 to December 22, 2000, in the three regions assumed to be the most affected with BSE in France (Basse-Normandie, Bretagne and Pays de la Loire). The samples were checked by using Prionics tests, and positive samples were confirmed by Western blot or immunohistochemistry. The overall prevalence of positive cattle was 0.16 per cent. Multifactorial logistic regression showed that there was a significantly higher prevalence among cattle from the birth cohorts July 1993 to June 1994 and July 1994 to June 1995, than among those born before July 1993, and among the categories 'euthanased' and 'emergency slaughtered' than among the category 'dead on-farm, and a higher prevalence in the regions Pays de la Loire and Bretagne than in Basse-Normandie. No significant differences in the prevalence of BSE were observed between dairy, beef suckler and mixed herds.     

Prevalence study on bovine tuberculosis and molecular characterization of its causative agents in cattle slaughtered at Addis Ababa municipal abattoir, Central Ethiopia

A cross-sectional study was conducted on 500 cattle slaughtered at Addis Ababa abattoir to determine the prevalence of bovine tuberculosis (BTB) and characterize its causative agents. Postmortem examination, mycobacteriological culturing, region of difference-4 (RD4)-based PCR and spoligotyping were applied. The prevalence of BTB was 5 % on the basis of postmortem inspection alone but 1.2 % based on molecular confirmation. Factors including age, sex, and breed showed statistically significant association with BTB (p?<?0.05). Gross lesions were observed most frequently (68 %) in the lungs and lung-associated lymph nodes compared to other organs and lymph nodes. Of the 25 grossly suspicious TB lesions processed and cultured, only six (24 %) were culture-positive, yielding Mycobacterium bovis confirmed by RD4 deletion typing. Further characterization of the six M. bovis isolates at the strain level by using spoligotyping revealed that one did not belong to any previously known type, while the others belonged to types SB1176 (two), SB1477 (two), and SB0133 (one). The new strain was submitted to the international M. Bovis.org database for international code designation. The study confirms the considerable prevalence of bovine tuberculosis in cattle slaughtered at Addis Ababa abattoir and highlights the need for control of bovine tuberculosis in the country.