Conceptual foundations for infectious disease surveillance.

The purpose of this report is to offer concepts for consideration in developing infectious disease surveillance systems, defined here as active, formal, and systematic processes intentionally directed to rapidly seek out and identify infectious disease agents or disease. Performance of surveillance systems can be judged by their accuracy (sensitivity and specificity), precision (repeatability), timeliness, multiple utility, and value. Surveillance system operation and function necessary to achieve high performance are defined in part by characteristics of the specific infectious disease, including disease transition state dynamics, that define probabilities of being in the latent, infectious, or clinical phase of disease. Two key components of surveillance are the sampling scheme, which is intended to maximize the probability of capturing an infected animal or specimen as soon as possible after the herd has been exposed, and the diagnostic assays, which should maximize the probability of detecting the agent, or evidence of the agent, if it is present in the specimen, while minimizing the likelihood of a false-positive result. Proportional risk sampling, targeted sampling, and repeated sampling are strategies that can improve overall surveillance system accuracy and particularly the temporal sensitivity related to early detection. Hierarchical sampling schemes and multiplexed assays can maximize efficiency and improve utility by serving multiple surveillance systems and purposes. Development of the surveillance systems needed to address emerging and foreign animal diseases will necessarily require design and architecture that are highly probability-driven to maximize surveillance sensitivity and specificity and to minimize cost.     

Advances in animal disease surveillance and biosecurity

Extract

Biosecurity is vitally important to New Zealand. We are more reliant on primary production than any other developed country, and the superior health status of our livestock is directly reflected in premium returns for New Zealand animal products in the international market place. Similarly, the indigenous flora and fauna that are a core part of our heritage and culture are highly valued by both New Zealanders and international visitors.     

畜禽传染病疫情动态及防制建议

1国外畜禽传染病疫情动态及防制经验畜禽传染病是对养殖业危害最严重的一类疾病,它不仅可能造成大批畜禽死亡和畜产品的损失,影响人民生活和对外贸易,而且某些人畜共患的传染病还能给人民健康带来严重威胁。尤其是现代化的养殖业,畜群饲养高度集中,调运频繁,更易受?..     

Technical and economic evaluation of different methods of Newcastle disease vaccine administration

Two types of locally produced live vaccines (HB1 and La Sota--lentogenic strains) and inactivated oil adjuvant (IOAV) vaccine were used to compare the efficiency of three vaccination techniques, namely drinking water, ocular and spray on broiler chicks. The ocular route of vaccination on 1-day-old chicks followed by a booster dose on the third week through the same route induced a significantly higher level of haemagglutination inhibition antibody titre (P < 0.0001). The highest mean antibody titre was log(2) 6.6 and 93.3% of the chicks were protected from the challenge. The spray technique induced a lower antibody titre (peak of log(2) 5.9) and only 53% of the chicks in this treatment survived against the challenge. The results of this study show that the ocular route is superior to the drinking water route, which is superior to the spray technique. The economic analysis result showed that the ocular HB1 and La Sota vaccine administration method to 1- and 21-day-old chicks gave the highest revenue followed by the drinking water method. In terms of total cost, the injection method required the highest cost (0.21 birr/chick) followed by the ocular method (0.18 birr/chick). The marginal cost of vaccine administration is too small compared with marginal revenues from relative effectiveness of the methods. The internal rate of return for the ocular method was very high. The results of sensitive analysis on revenues from different vaccination methods indicate that a 25% reduction in broiler price reduces the marginal revenue from the ocular method by 12 487 birr but this still does not prove that the ocular method is economically viable for small- and medium-scale poultry farms.     

Meeting report: panel on the potential utility and strategies for design and implementation of a national companion animal infectious disease surveillance system

This meeting report summarizes the discussions and recommendations of a Blue Ribbon Panel convened by the Science and Technology Policy Institute at the Institute for Defense Analysis on behalf of the White House Office of Science and Technology Policy (OSTP) on 13 September 2006 to discuss the potential utility and possible strategies for design and implementation of a companion animal health surveillance system. The panel comprised representatives from federal agencies, state agencies, academia, professional societies, and the private sector. The panel concluded that a companion animal surveillance system might prove valuable to efforts to protect public health, but that further study of the relationship between companion animal health and human health were needed to assess the utility and potential applications of a companion animal surveillance system. The findings of this panel may be used, along with other important sources of information, to inform policy discussions focussed on identifying strategies for recognizing and monitoring zoonotic disease threats appearing in companion animals in the USA.     

Detection and surveillance for animal trichinellosis in GB

The zoonotic disease trichinellosis is considered one of the re-emerging diseases with surveillance and control methods constantly gaining more importance worldwide. Recent change in European Union (EU) legislation introduces Trichinella-free production, and the possibility of risk-based monitoring for Trichinella in pigs. This has increased the role of wildlife surveillance programmes and their impact on protecting human health as well as highlighted the need for harmonised surveillance protocols and test methods for these infections. A modified digest method, based on the EU reference method for Trichinella testing of pig meat, was used to screen foxes present in Great Britain (England, Scotland and Wales) for trichinellosis. The method was validated using batched pools of 10 g foreleg muscle from up to 20 foxes (maximum amount 200 g). The method gave an average trichinae recovery rate of 71% for spiked samples. Assuming this recovery rate applies to all contaminated samples, then the test sensitivity would be 70% for all tissue samples with 0.1 trichinae per 10 g of foreleg muscle, 99.9% for samples with 1 trichinae per 10 g, and 100% for samples with 2 or more trichinae per 10 g. In two separate studies, conducted between 1999 to 2001 (Smith et al., 2003) and 2003 to 2007, over 3500 wild foxes have been screened for Trichinella with negative results. In the second study reported here, foxes were collected from locations throughout Great Britain using a stratified sampling method based on fox population densities. All work was conducted in compliance with appropriate quality assurance systems, latterly under ISO 9001. Results to date indicate the national prevalence of trichinellosis in foxes is <0.001 based on a 10 g individual sample size, an infection level of 1 larva per gram (l pg) and 95% confidence interval. This, together with no reports of trichinellosis in domesticated pigs, suggests that Britain can be considered a region of negligible risk of trichinellosis.     

宁夏各市县畜牧业经济指标的综合评价

运用主成分分析法对宁夏各市畜牧业经济指标作出综合评价，分析了各市县在宁夏畜牧业经济发展中的地位。     

转基因植物疫苗的开发及其在动物传染病防治中的应用

自首例植物疫苗投入市场来,许多植物物种经过遗传改造后用来表达抗原蛋白用于保护动物和人类健康。由于兽用疫苗比人用疫苗受到的限制比较少,所以吸引了大量的研究者、公司和投资商的关注,从而推动了转基因植物疫苗的迅速发展。植物疫苗可以直接口服免疫,避免了纯化过程,降低了生产成本,并逐渐走向成熟。本文就转抗原植物疫苗在发展中的问题、解决方案及其在动物传染病防治中的应用作一详细报道。     

对流免疫电流法诊断传染法氏囊病的研究

应用对流免疫电流技术（CIET）和琼脂扩散试验（AGP）对具有典型临床症状传染性法氏囊病鸡血清50份和法氏囊材料50份进行标准抗原检测被检血清，标准阳性因清检测被检抗原。AGP法标准抗原检测被检血清阳性40份，阳性率80％（40／50），标准阳性血清检测被检抗原，阳性36份，阳性率72％（36／50）；CIET法标准阳性血清检测被检抗原，阳性47份（47／50），阳性率为94％，标准抗原检测被检血清，阳性48份，阳性率为96％（48／50）。经x^2检验均P＞0.05，差异不显著。CIET法与AGP法，标准抗原检测被检血清，AGP法阳性率80％（40／50），CIET法阳性率96％（48／50）；标准阳性血清检测被检抗原，AGP法阳性率72％（36／50），CIET法阳性率94％（47／50）。经x^2检验均P＜0.05，差异显著。结果表明，CIET法比AGP法敏感、快速、且检出率高。     

鸡传染性法氏囊病活疫苗(B87株)病毒含量细胞间接免疫荧光方法的建立

为测定鸡传染性法氏囊病活疫苗（ B87株）的病毒含量,采用Vero细胞建立鸡传染性法氏囊病活疫苗（ B87株）病毒含量细胞间接免疫荧光方法,测定细胞半数感染量（ TCID50）。通过与传统鸡胚半数致死量（ ELD50）方法进行敏感性和相关性比较,间接免疫荧光方法具有更高的敏感性,两种方法的相关系数r为0．823。间接免疫荧光方法的建立为该疫苗的检验提供了一种新途径。     

On the surveillance for animal diseases in small herds

Small herds may present a problem in surveillance for infectious animal diseases because typical levels of a within-herd design prevalence are not directly applicable. We suggest a definition of small herds as those smaller than 2/(within-herd design prevalence) on the basis that such herds would be expected to have less than two (i.e. only one) infected animals. Consequently, the probability of detecting small herds cannot be improved by choosing a larger sample size within the herd. We derive necessary sample sizes of herds and the probability (“confidence”) of detecting disease within a stratum of small herds, given the among-herd design prevalence and test diagnostic sensitivity. Both a binomial model and a Poisson model can be used to establish the confidence for a given sample size of herds (and vice versa). The results of a simulation study suggest that the Poisson model provides more conservative (lower) estimates of the confidence for a given sample size and should therefore be preferred.     

提高秋季蚕茧单产的技术措施

我县已多年采用桑树冬季重剪,一年养四次蚕,即春、夏、秋、晚秋四次养蚕布局.     

Technical note: how to use Winbugs to draw inferences in animal models

This paper deals with Bayesian inferences of animal models using Gibbs sampling. First, we suggest a general and efficient method for updating additive genetic effects, in which the computational cost is independent of the pedigree depth and increases linearly only with the size of the pedigree. Second, we show how this approach can be used to draw inferences from a wide range of animal models using the computer package Winbugs. Finally, we illustrate the approach in a simulation study, in which the data are generated and analyzed using Winbugs according to a linear model with i.i.d errors having Student's t distributions. In conclusion, Winbugs can be used to make inferences in small-sized, quantitative, genetic data sets applying a wide range of animal models that are not yet standard in the animal breeding literature.     

搞好动物防检疫联动提高产地检疫率

《动物防疫法》规定“动物凭产地检疫证明出售、运输、参加展览、演出和比赛”。但从东海县近年来的实施情况看，目前生猪产地检疫率不足50％，牛、羊、家禽产地检疫率则更低，多用运输检疫取而代之。主要存在动物防疫和检疫脱钩，养殖和运输户对动物产地检疫重要性认识不足，图省事，不主动报检，收购屠宰部门不给予积极配合，动物检疫部门重点环节把关不够严格，监督执法部门对面广量大的动物产地检疫监督力不从心，有时难以到位等诸多问题，与国家的规定相差甚远。现就搞好动物防疫检疫联动，提高动物产地检疫率谈几点对策。