Various approaches of teaching veterinary parasitology

In this paper, we discuss the advantages and disadvantages of various approaches of teaching veterinary parasitology, including the disciplinary, the problem-oriented and combined approaches. In the disciplinary approach, parasitology is taught in the classical manner as a coherent subject, covering parasite morphology, biology, molecular biology, epidemiology, pathology, immunology, clinical manifestation, diagnosis, therapy, control, and prevention. Problem-oriented teaching approaches the subjects starting from diseases in animal species or from organ systems or other objectives (e.g. food safety); it also tackles training of skills for problem solving and self-learning. Combined approaches include elements of the disciplinary approach and those of other methods. A combined approach of teaching veterinary parasitology, including basic disciplinary teaching of at least 70-90 h, and additional problem-oriented education, was recently proposed in a resolution by the World Association for the Advancement of Veterinary Parasitology [WAAVP News Lett. 5 (1) 3-4]. In 1999, a new curriculum has been established at the Faculty of Veterinary Medicine, University of Berne, originally planned as a combination of organ-focused and problem-based approach. This model was soon identified to cause problems in teaching some disciplines, including infectious diseases. Conversely, the short-term experiences with this combined approach also confirmed some advantages of problem-oriented teaching in other, mainly clinical domains. Nevertheless, closer interdisciplinary contact and collaboration--especially in elective teaching--was enforced between paraclinical and clinical teaching by reforming the curriculum. However, it turned out that large student numbers in relation to the resources of manpower, rooms and finances limited the workability of the curriculum. Therefore, further and probably continuous improvement of the curriculum is necessary.     

The Utrecht model of teaching veterinary medicine and the role of veterinary parasitology

The Faculty of Veterinary Medicine, University of Utrecht, established a new curriculum for teaching veterinary medicine in 1995 with the main objectives to improve the problem-solving and communication competences of the students and their scientific education. Because it is accepted that graduates cannot get a starting competence in all fields of the veterinary profession, a differentiation of education focused on animal species and life-long learning is emphasised. Major characteristics of this curriculum are a high degree of horizontal and vertical integration of the various disciplines, the preference for teaching in small working groups and the training for self-learning. This curriculum is described in some detail. Parasitology is not taught as a coherent subject but is integrated into various subjects, presented in an interdisciplinary approach. The number of contact hours is variable depending on optional courses and the differentiation tracks taken but it amounts for a minimum of approximately 90 contact hours for each student during the full curriculum. A major disadvantage of the curriculum is that examination of parasitology is within integrated subjects. Thus, students that perform poorly on parasitology may still pass. An advantage is the extended presence of parasitology in the last year of clinical training and the improved interdisciplinary interaction between parasitologists and clinicians. The curriculum has been changed again in 2001; study paths focused on animal species and other subjects start already in the first year, and approximately 25% of the first 4 years of the curriculum will be within these study paths.     

History of veterinary parasitology in France

The history of veterinary parasitology in France can be divided into three parts. (1) The early period of veterinary education, and development of sections on parasites and parasitic diseases, immediately following the creation of the veterinary colleges in France in 1762-1765 by Cl. Bourgelat until the beginning of the 19th century. This was the period of academics, naturalists and zoologists, with the exception of P. Chabert who, as early as 1782, directed attention to the harmful effects of parasites on animals and tried to control them. (2) Identification and establishment of the field of veterinary parasitology and the development of specific research work, mostly in veterinary colleges, on the biology and systematic control of parasites. This period was dominated by the tremendous amount of work carried out by L.G. Neumann and A. Railliet in every topic of veterinary parasitology. (3) The modern period of veterinary parasitology (before and after World War II). This period is characterized by the increasing development of the most sophisticated techniques in fundamental and applied research to provide efficient cheap and practical means for the diagnosis and control of parasitic diseases in animals.     

The future of veterinary parasitology

Current evidence suggests research in veterinary parasitology is in decline despite its importance. This is particularly true in the UK where research funds have been diverted into BSE. Decline in interest in veterinary parasitology is at least in part due to the success of major pharmaceutical companies in producing a range of effective and safe anti-parasitic drugs. Research is needed because of the effects of parasites on animal welfare and the economic costs of parasites. However, there is little information on the actual costs of animal parasites. Another major reason for research is the development of drug resistance in protozoa, helminths and arthropods of veterinary importance. This is a serious problem particularly for sheep and goats in the southern hemisphere. A prioritised list of research requirements is suggested: (i) new drugs; (ii) resistance management; (iii) vaccines; (iv) breeding for resistance; (v) improved diagnostics; (vi) zoonoses; (vii) global warming and parasites. There is a major political challenge to raise the profile of veterinary parasitology and thus the funding essential for its advancement and the continued welfare and productivity of animals.     

PCR-based technology in veterinary parasitology.

DNA technology is having a major impact in many areas of veterinary parasitology. In particular, the polymerase chain reaction (PCR) has found broad applicability because its sensitivity permits enzymatic amplification of gene fragments from minute quantities of nucleic acids derived from limited amounts of parasite material. This paper discusses some recent applications of PCR-based methods to parasites and highlights their usefulness or potential for those of veterinary importance. The focus is on PCR tools for the accurate identification of parasites and their genetic characterisation, the diagnosis of infections, the isolation and characterisation of expressed genes, the detection of anthelmintic resistance, and mutation scanning approaches for the high resolution analysis of PCR products.     

The history of veterinary parasitology in Spain

A short history of the various contributions to the development of veterinary parasitology in Spain is given by considering five periods: (a) from the earliest times to the establishment of the first Veterinary Examination Board (Protoalbeiterato, A.D. 1500); (b) from 1500 to the creation of the Schools of Veterinary Medicine (1792-1793) and unification of the Veterinary profession (1850); (c) from 1850 to the appearance of parasitology as an autonomous discipline in the curricula; (d) from 1912 to the creation of Departments of Parasitology and Parasitic disease in the Faculties of Veterinary Medicine (1976); (e) from 1976 to the present day. In each period, the main contributions are considered and commented on, both from the parasitological and professional points of view. Finally, the role of veterinarians in modern Spanish parasitology is considered.     

Prospects for molecular vaccines in veterinary parasitology

Despite the profound developments in recombinant DNA technology there is only one marketed recombinant vaccine (for human viral hepatitis B). The development of others proceeds with great difficulty. Molecular vaccines against veterinary parasites are at the utmost pole of complexity in the spectrum of potential vaccines since these parasites are complex eukaryotic organisms, often dwelling at mucosal surfaces where anamnestic responses are problematic, where the immunogenicity of the parasite components is poorly understood and where the effector mechanisms of immunity are unresolved. Cloning a "protective" gene is only the first step, and perhaps the easiest, in a long process which will be necessary to develop vaccines against parasites. Additional steps will involve comprehensive analyses of the immunological responses to ensure that vaccine antigens contain the correct epitopes to induce appropriate immune effector mechanisms for parasite elimination and immunological memory and that these responses are not genetically restricted. The great expectations for recombinant vaccinia-based vaccines must be modified substantially in the light of recent evidence indicating immunological and other constraints on this approach. The use of anti-idiotype vaccines is an underexplored opportunity for practical parasite vaccines since they have several potentially important advantages. The need to include T cell antigenic peptides in peptide vaccines to extend the range of genetic responsiveness and to induce anamnestic responses is now clear. New algorithms for the prediction of such sites exist and these can be tested experimentally with synthetic peptides. There are no major technical obstacles to the development of vaccines for parasites which cannot be overcome. However substantial long term basic research is needed over a range of disciplines to achieve this worthwhile objective.     

Teaching veterinary parasitology throughout the world

In order to understand how the teaching of parasitology in veterinary schools and faculties in the world is carried out, a questionnaire was sent to all centres listed in the W.H.O. World Directory. A total of 91 replies were received. Additional information was obtained from the report of a symposium held in Hannover, Germany in 1978 and from the Education Committee of the American Association of Veterinary Parasitologists in 1981. The academic level, the place of parasitology in the veterinary curriculum, textbooks and practical instruction, evaluation techniques, teaching staff, institute organization and publications are discussed.     

The role of molecular biology in veterinary parasitology

The tools of molecular biology are increasingly relevant to veterinary parasitology. The sequencing of the complete genomes of Caenorhabditis elegans and other helminths and protozoa is allowing great advances in studying the biology, and improving diagnosis and control of parasites. Unique DNA sequences provide very high levels of specificity for the diagnosis and identification of parasite species and strains, and PCR allows extremely high levels of sensitivity. New techniques, such as the use of uniquely designed molecular beacons and DNA microarrays will eventually allow rapid screening for specific parasite genotypes and assist in diagnostic and epidemiological studies of veterinary parasites. The ability to use genome data to clone and sequence genes which when expressed will provide antigens for vaccine screening and receptors and enzymes for mechanism-based chemotherapy screening will increase our options for parasite control. In addition, DNA vaccines can have desirable characteristics, such as sustained stimulation of the host immune system compared with protein based vaccines. One of the greatest threats to parasite control has been the development of drug resistance in parasites. Our knowledge of the basis of drug resistance and our ability to monitor its development with highly sensitive and specific DNA-based assays for 'resistance'-alleles will help maintain the effectiveness of existing antiparasitic drugs and provide hope that we can maintain control of parasitic disease outbreaks.     

RAPD及其在兽医寄生虫学上的应用

随机扩增多态DNA技术 (RAPD) ,近年来已越来越多地应用于兽医寄生虫学研究中 ,尤其在虫种分类 ,流行病学研究和种群变异等方面的报道较多 ,本文结合作者的工作 ,对此作一概述     

Teaching of undergraduate veterinary parasitology in some European countries

A review revealed that at 20 veterinary faculties in European countries parasitology is represented in the curriculum of veterinary medicine with an average of 105 core contact hours, devoted to lectures (58%) and practicals (42%). However, there is a high diversity between faculties with ranges of total contact hours between 48 and 156. Three faculties are close to the minimum of 70 core contact hours recommended by WAAVP (2002), and one faculty is below this limit. In one of the faculties parasitology is completely integrated into interdisciplinary teaching activities, in some others there are developments in this direction which include the risk of dissolving parasitology as a discipline. One faculty with a high degree of integrated teaching has already abolished the parasitological examination. Parasitology is preferentially taught in the years three, four and five of the curriculum, but there is great variation between the faculties. Most teachers in the faculties are veterinarians. In many faculties the large numbers of students and the unsatisfactory academic teaching staff:student ratio represent a significant problem. This problem may increase with more teaching obligations caused by new curricula. Due to the high diversity in content and structure of teaching curricula of veterinary medicine between veterinary faculties in Europe international and even national exchange of students is inhibited. Therefore, and for many other reasons more activities should be initiated towards harmonisation of the study curricula in Europe.     

对《中国兽医寄生虫学》的回顾与展望

我国兽医寄生虫学科的建立与发展已有 70年左右的历史了 ,为使本学科领域内的工作者了解学科的发展史和更好地继承与发展该门学科 ,本刊从本期起设立兽医寄生虫学“学科史料”栏目 ,先刊登“中国兽医寄生虫学的回顾与展望”一文 ,以后再陆续刊登这方面内容的文章 ,欢迎大家投稿。稿件内容可以是学科某一方面发展的综述 ,也可以只报道学科发展中的某个重大事件 ,如某一种重要寄生虫病的发现 ,一个重要寄生虫生活史的研究成果 ,一种重要检测或防治技术的创建等 ,并列出对这一重大贡献中起重要作用的专家姓名 ,以便于读者们学习与敬仰。     

兽医寄生虫病研究的回顾与展望

改革开放以来 ,我国畜牧业迅猛发展 ,是推动我国农业和农村经济发展、提高农民收入的重要动力。要保证我国畜牧业的持续稳定发展 ,应对入世对我国畜牧业的挑战 ,必须不断地提高畜禽疫病的防治水平。我国是一个发展中国家 ,社会、经济、生活条件相对落后 ,幅员辽阔 ,地形地貌与气象环境差别大 ,因此 ,畜、禽寄生虫病种类多、分布广、流行严重、防治难度大 ,严重制约我国畜牧业的发展。分析我国畜禽寄生虫病防治研究的现状 ,明确新世纪努力的目标 ,对提高我国畜禽寄生虫病防治水平将有积极的意义。1　回顾近一、二十年来 ,经过广大寄生虫学工…     

Teaching of veterinary parasitology: the Italian perspective

The curriculum in veterinary medicine in Italy is undergoing important changes, as in the rest of Europe. The 2001 fall semester will mark the beginning of a new format for the degree in veterinary medicine and these changes will obviously affect the teaching of veterinary parasitology. In Italy, veterinary parasitology is usually taught in the third year with a disciplinary approach, similar to that described by Euzéby [Vet. Parasitol. 64 (1996) 21] and Eckert [Vet. Parasitol. 88 (2000) 117]. Approximately 90 h of lectures and 40 h of laboratory are offered and are usually divided into parasitology, followed by parasitic diseases. A more problem-oriented approach to parasitology is offered to fifth-year students within several professional routes (large animal medicine, small animal medicine, hygiene and food safety, etc.), amounting to approximately 15-60 h per student. Indeed, in the last year of study, there are less students and it is possible to present clinical cases and orient the students towards team work and critical discussion. This new curriculum guarantees a reduction in the number of lecture hours and an increase in both laboratory work and personal study, as suggested by the guidelines of the European association of establishment for veterinary education (EAEVE).