2017—2020年广西部分猪场送检血清猪伪狂犬病抗体检测

为了解广西猪场伪狂犬病毒（PRV）感染和免疫状况,2017年1月—2020年12月,对部分猪场随机采样送检的血清样品,应用ELISA方法开展PRV血清抗体检测,并对检测结果进行不同年份、不同季节、不同地区、不同生长阶段猪群的统计分析。结果显示：从时间分布上看,2018年PRV gE抗体场阳性率（57.71%）和个体阳性率（24.75%）均最高,此后呈逐年下降趋势,其中个体阳性率下降明显（P＜0.05）,2020年下降至6.14%;各年间的PRV gB抗体场合格率差异不显著（P＞0.05）,均在90%以上,而2019年的个体阳性率（88.71%）最低,与其他年份差异显著（P＜0.05）。冬季PRV gE和gB抗体个体阳性率最低,分别为14.96%和89.35%,与其他季节差异明显（P＜0.05）;冬季gE抗体场阳性率（42.97%）最低,与春季、秋季差异不显著（P＞0.05）,但显著低于夏季（P＜0.05）,而gB抗体场合格率一年四季差异不显著（P＞0.05）,均在95%以上。从空间分布上看,广西14个地市猪场均存在不同程度的PRV野毒感染,其中玉林市最严重,场阳性率和个体阳性率分别为69.51%和35.86%,而钦州市最轻,分别为16.67%和4.07%;PRV gB抗体个体合格率普遍较高,均在84%以上。从不同生长阶段猪群上看,后备母猪、育肥猪PRV gE和gB抗体个体阳性率均显著低于其他生长阶段猪群（P＜0.05）,其中gE抗体个体阳性率在13%以下,而gB抗体个体阳性率不足80%。结果表明,近年广西规模猪场PRV野毒感染率较高,而疫苗免疫并不能完全阻止野毒株感染。建议通过PRV净化和提高规模猪场生物安全水平等措施来控制其流行。本研究为制定合理的猪伪狂犬病防控与净化策略提供了依据。     

Comparison of breeder/layer coccidiosis vaccines: Part 2: Onset of immunity – attenuated vaccines

Coccidiosis control for breeding and laying chickens requires the development of immunity against multiple Eimeria species. Only one vaccine was widely available to producers in the European Union (EU) from 1991 until 2015. Recently, 2 new products have been introduced to the market. The 3 vaccines were compared with respect to the onset of immunity in pen studies, where sample birds were challenged at 21, 25, 28, and 32 d of age to determine the time at which lesion scores became significantly different from unvaccinated controls, the “onset of immunity.” The vaccines were given by oral gavage to eliminate any effect of application methodology on the onset of immunity. “Complete Immunity,” defined as no coccidiosis lesions following challenge, was only achieved for one species (Eimeria tenella) by one vaccine through the final challenge at 32 d. Immunity remained incomplete for all other challenge groups for the duration of the experiment. Onset of immunity was detected by 25 d of age in only one vaccine group for all 5 challenge species tested (E. acervulina, E. maxima, E. tenella, E. necatrix, E. brunetti); and while onset of immunity was detected for some species with the other vaccines by 21 to 32 d of age, neither of the other 2 vaccines demonstrated onset of immunity to all 5 challenge species by the end of the experiment. Delayed onset of immunity could adversely affect pullet weight with early field challenge, as indicated by bird weights taken before and after challenge.     

2016年-2017年新疆规模化猪场伪狂犬病抗体检测

为了解新疆地区不同规模化猪场伪狂犬病病毒(PRV)野毒感染情况,采用ELISA对2016年4月-2017年12月来自67个不同规模化猪场的2 516份血清进行了PRV-gE抗体血清学调查。结果显示,血清总阳性率为34.02%,2016年和2017年阳性率分别为17.77%和39.52%;哺乳仔猪、保育猪、育肥猪、后备母猪、妊娠母猪、哺乳母猪、公猪总阳性率分别为26.07%、22.35%、35.38%、32.70%、33.13%、31.06%和31.71%;猪场总阳性率为82.09%,北疆、南疆和东疆猪场阳性率分别为78.57%、100.00%和100.00%。结果表明,2016年-2017年新疆地区猪群中PRV感染率明显上升,南疆与东疆地区阳性率显著高于北疆地区,各个阶段猪群阳性率均显著升高,母猪与公猪感染加重是伪狂犬病持续存在的重要原因,对其进行防控与净化刻不容缓。     

几种布鲁氏菌病检测方法比对结果分析

为比较几种常用布鲁氏菌病(简称布病)检测方法特性,在某疫苗免疫的奶牛场随机选取40头奶牛,采集血清和奶样各40份,然后对采集的血清进行虎红平板凝集、试管凝集、胶体金、酶联免疫吸附试验(iELISA和cELISA)和琼脂扩散方法检测,对采集的奶样进行病原学检测(qPCR)和抗体检测(胶体金)。结果显示:4种国标方法(虎红平板凝集、试管凝集、iELISA和cELISA)检出的阳性样品数量有较大差距,分别为16、6、23和33份,其中经试管凝集试验检出的阳性血清,经其他3种国标方法也检测为阳性;通过胶体金法检出阳性血清数(9份)略高于试管凝集试验,且血清及牛奶样品经胶体金检测结果基本一致;琼扩法检出12份阳性血清,且显示抽检奶牛中存在野毒感染;qPCR和胶体金试纸条对采集奶样的检测结果有较大差距,经qPCR检测仅1份样品呈阳性。结果表明:国标方法中,试管凝集试验特异性最高,iELISA和cELISA敏感性较高;病原学检测临床样品检出率较低,琼脂扩散试验敏感性有限,胶体金法敏感性适中,操作简便,适合布病免疫奶牛场自检。本研究为牛场布病不同检测目的方法选择提供了参考。     

A history of canine parvovirus in Australia: what can we learn?

Canine parvovirus (CPV) has been reported throughout the world since the late 1970s. Published information was reviewed to draw insights into the epidemiology, pathogenesis, diagnosis, treatment and outcomes of CPV disease in Australia and the role of scientific research on CPV occurrence, with key research discoveries and knowledge gaps identified. Australian researchers contributed substantially to early findings, including the first reported cases of parvoviral myocarditis, investigations into disease aetiopathogenesis, host and environmental risk factors and links between CPV and feline panleukopenia. Two of the world's first CPV serological surveys were conducted in Australia and a 1980 national veterinary survey of Australian and New Zealand dogs revealed 6824 suspected CPV cases and 1058 deaths. In 2010, an Australian national disease surveillance system was launched; 4940 CPV cases were reported between 2009 and 2014, although underreporting was likely. A 2017 study estimated national incidence to be 4.12 cases per 1000 dogs, and an annual case load of 20,110 based on 4219 CPV case reports in a survey of all Australian veterinary clinics, with a 23.5% response rate. CPV disease risk factors identified included socioeconomic disadvantage, geographical location (rural/remote), season (summer) and rainfall (recent rain and longer dry periods both increasing risk). Age <16 weeks was identified as a risk factor for vaccination failure. Important knowledge gaps exist regarding national canine and feline demographic and CPV case data, vaccination coverage and population immunity, CPV transmission between owned dogs and other carnivore populations in Australia and the most effective methods to control epizootics.     

Comparison of antibody responses after vaccination with two inactivated rabies vaccines

Thirty laboratory dogs were randomly assigned to two groups (A and B) of 15 dogs and subcutaneously vaccinated with a single dose of one of two commercially available monovalent inactivated rabies vaccines: RABISIN (Merial, France) (group A) and NOBIVAC Rabies (Intervet International) (group B). Rabies antibodies were measured over a period of 4 months using the fluorescent antibody virus neutralization (FAVN) test. The two vaccines performed differently in terms of magnitude and persistence of rabies antibodies titers in dogs. Two weeks after vaccination, average rabies antibody titers peaked at 2.53 IU/mL (range, 0.17-13.77 IU/mL) and 1.26 IU/mL (range, 0.50-4.56 IU/mL) in groups A and B dogs, respectively. The average FAVN antibody titres against rabies on D28, D56, D84, D112 and D120 were significantly higher in group A than in group B. Although all dogs from group B serologically responded to vaccination, the proportion of dogs with antibody titres >or=0.5 IU/mL dropped significantly after D28 and was statistically significantly lower on D56, D84 and D112 compared to group A dogs. In conclusion, in the context of international trade, the choice of the vaccine and the timing of blood tests are critical factors in achieving successful serological test results after rabies vaccination. RABISIN induces high and sustained antibody titres against rabies, increasing the flexibility for the time of blood sampling after primo-vaccination.     

四川部分种猪场乙型脑炎血清抗体调查

2001年我室从省内已免疫乙脑的8个种猪场采集了597份猪血清进行了乙型脑炎血清抗体检测，结果抗体阳性率仅达32．83％，37．50％的种猪场血清抗体阳性率低于10％，免疫水平低下，不能有效保护种猪免受乙型脑炎感染。应采取积极的预防措施，采用有效的疫苗进行免疫，有效的防止种猪场流行性乙型脑炎的发生。