Clinical chemistry. In-clinic analysis, quality control, reference values, and system selection

The clinician never has had a better selection of user friendly analytical systems for in-clinic use. Selection of a system should be made only after several questions have been answered, including: What is the technical knowledge and experience of the persons who will use the system? Who will initiate and supervise a quality assurance program? Which analysis and what volume of samples are anticipated now and in the future? The estimated cost per test should include the total cost of instrumentation and maintenance, calibrators, controls, reagents, and technical and supervisory time. Have the methods been validated for the animal species involved and are adequate reference values available? Read the package inserts completely for each analyte. Do not rely on the advice of salespeople for guidance in answering many of these questions, but do question them carefully about statements made, especially regarding warranties and technical service. For those clinicians willing to accept the responsibilities associated with in-clinic testing, an increased awareness of laboratory medicine and a resulting increased interest and ability to provide quality medical care can be expected.     

Perspectives and advances in in-clinic laboratory diagnostic capabilities: hematology and clinical chemistry.

The typical technologies used in veterinary hematology and biochemical analyzers are reviewed, along with associated advantages and disadvantages. Guidelines for implementing a successful in-clinic laboratory are provided, including criteria for system evaluation and expectations for comparative performance evaluations. The more common problems and limitations associated with in-clinic laboratory diagnostics and how to best prevent them are also discussed.     

Evaluation of an in-clinic Serum Amyloid A (SAA) assay and assessment of the effects of storage on SAA samples

Background

An in-clinic assay for equine serum amyloid A (SAA) analysis, Equinostic EVA1, was evaluated for use in a clinical setting. Stability of SAA in serum samples was determined.

Methods

Intra- and inter- assay variation of the in-clinic method was determined. The in-clinic method (EVA1) results were compared to a reference method (Eiken LZ SAA) with 62 patient samples. For samples with SAA concentrations within the assay range of EVA1 (10-270 mg/L), differences between the methods were evaluated in a difference plot. Linearity under dilution was evaluated in two samples. Stability of SAA in three serum pools stored at 4°C and approximately 22°C was evaluated with the reference method day 0, 1, 2, 4, 7, 17 and analysed with a two-way ANOVA.

Results

The imprecision (coefficient of variation, CV) for the in-clinic method was acceptable at higher SAA concentrations with CV values of 7,3-12%, but poor at low SAA concentrations with CV values of 27% and 37% for intra- and inter-assay variation respectively. Recovery after dilution was 50-138%. The in-clinic assay and the reference method identified equally well horses with low (<10 mg/L) and high (>270 mg/L) SAA concentrations. Within the assay range of the in-clinic method, 10-270 mg/L, the difference between the two methods was slightly higher than could be explained by the inherent imprecision of the assays. There were no significant changes of serum SAA concentrations during storage.

Conclusions

The in-clinic assay identified horses with SAA concentrations of <10 mg/L and >270 mg/L in a similar way as the reference method, and provided an estimate of the SAA concentration in the range of 10-270 mg/L. The imprecision of the in-clinic method was acceptable at high SAA concentrations but not at low concentrations. Dilution of samples gave inconsistent results. SAA was stable both at room temperature and refrigerated, and thus samples may be stored before analysis with the reference method.     

La gestion sanitaire des élevages de rongeurs utilisés en recherche biomédicale: II. Les facteurs pouvant influencer I'implantation d'un programme de gestion sanitaire

Factors influencing the implementation of a monitoring program     

Hematology without the numbers: in-clinic blood film evaluation.

Technical advances have made it possible for many private veterinary practices to purchase reasonably priced automated hematology instruments to perform in-clinic blood analyses. Although these instruments can quickly provide "numbers" to the clinician, evaluation of a well-made blood film can often provide information critical to the interpretation of those numbers. Blood film review is essential to identify important abnormalities such as neutrophilic left shifts and toxic change, neoplastic cells, hemoparasites, and erythrocyte morphologic changes that may suggest the cause of an anemia. Additionally, the blood film provides an important quality control measure for the automated hematology results. This article outlines a simple method of blood film evaluation, highlights the most common clinically important abnormalities, and reinforces the importance of blood film evaluation as a quality control measure.     

国家动物源细菌耐药性监测工作的探讨和建议

介绍了国外动物源细菌耐药性监测工作的情况及目标,对我国的动物源细菌耐药性监测工作需考虑的许多因素进行了介绍和讨论,包括动物品种、食品、采样方法、样本的收集、细菌品种、抗菌药物、标准药敏试验法、质控、结果记录和数据库设计、报告和结果分析等,并对今后的动物源细菌耐药性监测工作提出了建议。     

IBR and BVD control: the key to successful herd management

Control of IBR and BVD should be possible in Europe. Effective vaccines and reliable tools for monitoring are available. Systematic approach and strict implementation of control measures are essential. Voluntary or mandatory programs are ongoing on regional or national level in a lot of countries. Successful programs put pressure on surrounding regions/countries to initiate control program as well.     

HACCP在酱鸭生产中的应用研究

HACCP是一个对食品质量进行控制的保证体系，现正被世界上越来越多的国家所采用。本文主要按照HACCP体系监控要求对酱鸭生产过程进行危害分析，确定关键控制点，建立关键限值和有效的监测方法，从而生产出安全、优质的酱鸭。     

免疫抗体监测在动物疫病防控中的应用

从利用免疫抗体监测考核免疫效果、制定科学的免疫程序、评价疫苗的质量、预警重大动物疫病等方面,综述了免疫抗体监测在动物疫病防控中的应用,以供参考。     

Veterinary herd health and production service on dairy farms IV. Index list on calf rearing and cow culling

The Herd Health and Production Service program for use in veterinary dairy practice is comprised of a basic and a flexible system. The basic system is a uniform system of data recording, standard veterinary activities and problem detection. In problem detection 4 index lists play a key role. The 4 comprise of the parameters or index figures that are relevant in monitoring the efficiency of milk production, calf rearing and cow replacement. Data on milk production, health status and reproduction of both individual animals and the herd are collected by the farmer and the veterinarian and transformed into index figures.This paper introduces index list “3”, with index figures for the monitoring of calf rearing and cow culling as parts of a herd health program. The development, implementation and significance of the index figures are presented. The index figures serve to detect unsatisfactory farm situations or problems in calf rearing and in cow culling. They trigger further investigation and aid the solution to and prevention of problems. Relationships with farm parameters mentioned in other index lists are also considered. Objectives and reference values where applicable are provided.     

Comparison of a clinic-based ELISA test kit with the immunofluorescence test for the assay of Ehrlichia canis antibodies in dogs.

The "gold standard" for the detection of antibodies to Ehrlichia canis, the cause of canine monocytic ehrlichiosis (CME), is the indirect immunofluorescence antibody (IFA) test. The IFA test however is generally available only in selected laboratories and requires extensive equipment and trained personnel. A double-blind study was conducted to compare the ability of an in-clinic standardized enzyme-linked immunosorbent assay (ELISA) test kit to measure E. canis IgG antibodies in dogs compared with the standard IFA technique. A good correlation was found between the 2 techniques (r2 = 0.8793; P < 0.0001). Evidence for the sensitivity of the ELISA technique for the early detection of E. canis IgG antibodies was demonstrated by comparing the appearance of E. canis antibody titers by the IFA and ELISA techniques after artificial infection of 2 sets of dogs. In both experimental infections, both tests were equally sensitive for the early detection of IgG antibodies against E. canis, and the results correlated well with the appearance of fever and clinical signs. Proposed application of the in-clinic ELISA test is to aid in the diagnosis of CME.     

动物血液样品的采集保管存在问题及对策

血液样品的采集和保管,在动物抗体监测检验工作中是一个十分重要的环节,也是保证监测结果正确性的必要前提,如果忽视了这一点,就会直接影响血样的质量,进而造成监测结论不正确而对免疫程序和免疫效果错误评估,最终导致动物综合防疫措施达不到预期目标。因此,笔者结合动物抗体监测工作中出现的问题,就如何正确进行血液样品的采集和保管谈几点体会,仅供参考。     

生产者责任延伸制度实施方式差异及绩效评价

生产者责任延伸制度（EPR）是以现代环境管理原则实现产品系统环境性能改善的一种政策性工具。生产者责任延伸政策在世界各国有不同的实施方式,通常有企业自愿、法律强制、经济手段刺激、协议执行以及几种方法综合使用等手段。决策者选择不同的实施方法是基于本国文化、国情、经济基础、国家环境政策和目标、优先解决的环境问题等各方面情况的综合考虑。各种不同的实施方法的环境效益和经济效益是不一样的,这也往往成为决策者选择的另一个依据,也值得后续准备采用KPR政策的国家借鉴。     

Evaluation of a new in-clinic method for the detection of canine heartworm antigen

Canine heartworm is endemic in many parts of the world, and veterinarians rely on rapid in-clinic antigen tests to screen for this infection. Recently, an in-clinic, instrument-based rotor employing a colloidal gold agglutination immunoassay was launched in the marketplace (VetScan VS2(?) Canine Heartworm (HW) Antigen Test Kit; Abaxis, Inc.). Because of the widespread use of heartworm prevention and possible false negative test results in dogs with low heartworm burdens, the performance of the VetScan VS2(?) HW test and a commercially available in-clinic, membrane-based ELISA test (SNAP(?) Heartworm RT Test; IDEXX Laboratories) was compared using samples from dogs with low heartworm burdens and/or low levels of circulating antigen. Ninety serum samples were evaluated using the two methods. Testing was performed according to the manufacturer's product insert by personnel blinded to sample status. The samples were derived from two populations: dogs with necropsy-confirmed heartworm status (40 with 1-4 female worms, 30 with no worms), and field dogs (20) confirmed positive for antigen by microtiter plate ELISA (PetChek(?) Heartworm PF Antigen Test; IDEXX Laboratories). All 40 dogs with heartworms on necropsy were also confirmed to have circulating antigen by the PetChek HW ELISA. In necropsy-negative dogs (n=30), neither the VetScan VS2 HW nor SNAP HW tests detected heartworm antigen. Of the samples testing positive for antigen by PetChek HW (n=60), the VetScan VS2 HW and SNAP HW tests detected antigen in 15 and 56 samples, respectively. Percent agreement (plus 95% confidence interval) for each test relative to the PetChek HW qualitative result was 50% (40-60%) for VetScan VS2 HW and 96% (89-98%) for SNAP HW. Relative to the presence or absence of female worms at necropsy, agreement was 61% (50-72%) for VetScan VS2 HW and 99% (92-99.6%) for SNAP HW tests. It is clinically important that dogs with low heartworm burdens and/or low levels of circulating heartworm antigen be correctly identified by veterinarians in order to ensure prompt treatment, and the VetScan(?) VS2 HW test does not appear to be as accurate as the SNAP HW or PetChek HW tests when performed on this subset of patients.     

Producer quality assurance programs.

Essentially all animal commodity organizations have established quality assurance programs designed to ensure food safety and quality. Most of these programs were originally implemented to address problems with veterinary drug residues. Many of the current programs have or plan to include food safety critical control points with specific guidelines on how to control or reduce pathogen load. The continued focus placed on food safety by today's consumer demands that American producers ensure that their commodities are wholesome, safe, and of high quality in order to remain competitive in the global marketplace. Veterinarians should recognize that it is important to encourage food animal producers to participate in quality assurance programs for their clients' economic health and for food safety and protection of public health. Commodities certified as being produced under good production practices or by producers certified as following a recognized and validated quality assurance program often bring a premium price. Also, some slaughter establishments are beginning to require producers to be certified as practicing under a recognized quality assurance program before animals are accepted for processing. This practice is being driven partially by the demands placed on slaughter establishments by the US Department of Agriculture's implementation of the Pathogen Reduction, Hazard Analysis and Critical Control Point Systems regulation. Regardless of why producer trade association quality assurance programs have come into existence, veterinarians should promote the programs as an excellent mechanism to help ensure everyone's goal of a safe, wholesome food supply.     

ASVCP quality assurance guidelines: external quality assessment and comparative testing for reference and in‐clinic laboratories

The purpose of this document is to educate providers of veterinary laboratory diagnostic testing in any setting about comparative testing. These guidelines will define, explain, and illustrate the importance of a multi‐faceted laboratory quality management program which includes comparative testing. The guidelines will provide suggestions for implementation of such testing, including which samples should be tested, frequency of testing, and recommendations for result interpretation. Examples and a list of vendors and manufacturers supplying control materials and services to veterinary laboratories are also included.     

Laboratory procedures.

The main foundation to veterinary medicine is the availability of laboratory tests. These tests may be performed in-clinic or at diagnostic laboratories. In-clinic testing is advantageous in producing quick results, but demands sound technical ability, basic equipment,and access to some routine and special reagents. Laboratory-based testing can back up those routine techniques that mayor may not be available at the clinic level as well as provide specialized testing. The knowledge of commercially available diagnostic services is important as well as preparation and proper shipping of samples for accurate determinations.     

水禽禽流感免疫防控关键技术与措施

如何提高水禽禽流感（AD免疫防控的效果,一直是临床兽医工作者所关注的问题。本文根据“水禽禽流感的免疫防控关键技术研究”所获得的主要成果,从疫苗质量控制、免疫程序制订与实施、免疫效果监测、卫生与饲养管理措施等重要方面陈述了水禽AI防控的技术要点,望对提升水禽AI的防控水平、增加水禽养殖业收益方面有所帮助。     

中国与美国及新西兰牛奶兽药残留监测计划的比较

目的：比较中国与美国及新西兰牛奶兽药残留监测计划的差异和不足,为完善我国牛奶兽药残留监测计划提供参考。方法：收集2008-2011年中国、美国及新西兰的牛奶兽药残留监测计划的数据,比较各个国家实施监测计划的药物种类、样本量以及实施结果。结果：我国与美国及新西兰牛奶兽药残留监测计划相比,监测药物种类与美国及新西兰相近,但检测量少,难以覆盖所有牧场;2011年度的中国与美国及新西兰牛奶抗生素残留监测的检测结果为：中国的检出率高于美国和新西兰（P〈0．05）,有统计学意义。建议在监测计划中扩大监测范围,增加检测量,使监测计划能覆盖更多地区和牧场。     

Implementation of herd health program to improve survival of Boer goats in Malaysia

A Boer goat breeding farm with 800 heads of breeder females, 50 breeder males, and 400 growing goats of various ages in Sabah, Malaysia was selected to study the effect of implementing herd health program. This included vaccination program against pneumonic mannheimiosis; fecal monitoring for helminthiasis, coccidiosis, and colibacillosis; and introduction of modified feeding regime comprised of day-time grazing and feeding of cut grass and supplemented feed. The herd health program was implemented in September 2007 and the impact was observed on body weight gains, body scoring, and annual mortality among adults and kids. It was found that implementation of herd health program significantly (p < 0.05) increased the average body weight gains in both adults and kids from 1.8 g per kid and 0.6 g per adult in 2006 to 3.7 g per kid and 2.2 g per adult in 2008. The percentage of adults with body scoring of <3 was significantly (p < 0.05) reduced from 82.3% in 2006 to 77.6% in 2007 and 4% in 2008. Similarly, the annual mortality rate was significantly (p < 0.05) reduced from 6.5% among kids and 58.2% among adults in 2006 to 12.1% among kids and 10.4% among adults in 2007, and to 9.1% among kids and 1.1% among adults in 2008. Therefore, it was concluded that implementation of herd health program significantly improved the survival and performance of goats.