EPIDEMIOLOGY, HYGIENE AND CONTROL OF INFECTIOUS DISEASES
Learning outcomes of the course unit
At the end of the course the student in accordance to Dublin descriptors must have acquired:
D1: Knowledge and understanding. This means to know and understand the most common problems using an epidemiological and a preventive approach.
D2: To apply Knowledge and understanding. The student should cope the problems applying epidemiologic and preventive criteria.
D3 - Making judgement. The student must know factor characterizing health e disease status. In addition the student must know the transmission route of infectious diseases and their pathogenetic evolution.
D4 - Comunication skills. Student should express the notions by using terms acquired during the course of epidemiology.
D5 - Learning skills. The student must have the basis e the critical skills to face complex problem by using the foundamental elements acquired during the course, but even consulting books or scientific papers.
Elements of statistics and microbiology.
Course contents summary
Study of the methods applied to the understanding of the epidemiology of animal diseases. The aim of the course is the study of bacterial and virus involved in infectious disease of domestic animals: in particular the basic concepts relating to the nature and classification of bacteria and viruses, their pathogenic potential, the main investigation methods and measures of control.
1. Introduction to the study of epidemiology. Historical considerations and basic concepts. Differences between epidemiology and other diagnostic disciplines. The concept of disease determinant. Primary determinants. Secondary determinants. The concept of "population". Levels of populations.
2. Tasks and aims of epidemiology. Tasks of veterinary epidemiology. Prevention, control and eradication of diseases. The aims of epidemiological studies. Observational and experimental studies.
3. From association to causality. Demonstration of causality in observational studies. Statistical significance and causality. Chi-square test for comparing two percentages. Statistical significance tests. Association and causality: types of association. General model of causal and non-causal associations. Examples of causal and non-causal associations.
4. The epidemiological approach to the causes of disease. Henle-Koch's postulates. Evans's postulates. The Rules of John Stuart Mill. Demonstration of causality. Criteria of causality. Prospective and retrospective studies for demonstrating causality. Prevalence rate, relative risk and odds ratio.
5. Biological variability: basic concepts in epidemiology. Frequency distribution. Cumulative, median and centile frequencies. Central tendency indices. Variation indices.
6. Sampling in veterinary practice. Aims of sampling. Characteristics of a good sample. Sampling errors. Sampling methods. The variability of an estimate and confidence limits. Sample size.
7. Measuring disease frequency. General concepts. Morbidity and mortality. Survival and lethality. Prevalence and incidence. Attack rate. Relationship between incidence and prevalence. Epidemic, endemic and sporadic diseases. Other methods for measuring disease frequency. Standardisation of measures.
8. Screening tests for sub-clinical diseases. Population screening. Test performance assessment. Sensitivity, specificity, positive and negative predictive value. Methods for improving the predictive value of a test. Multiple tests: use of two tests simultaneously or in succession; serial or parallel interpretation. Concordance index between two tests.
9. Transmission and maintenance of infectious diseases Transmissible diseases. The cycle of a transmissible disease. Latent infection and carrier status. Horizontal and vertical, direct and indirect transmission. Host types. Mechanical and biological vectors. Factors associated with the spread of infections. The spread of infections and host characteristics: receptiveness and contagiousness. The spread of infections and agent characteristics. The spread of infections and contact efficiency. Routes of infection. Transmission modes. Long distance transmission of disease agents. Vertical transmission of disease. Maintenance and survival strategies of the agent.
10. Disease patterns. Epidemic curves. Kendall’s threshold theorem. Epidemic trends. Common source and propagation epidemics.
11. Models in epidemiology. Model types and functions. A classic model: the Reed & Frost model.
16. Bovine and swine enteric diseases.
18. Newcastle disease.
19. Bovine and swine herpesviruses
20. Bovine and equine retrovirus
21. Vectorial diseases.
22. Rabbit mixomatosis.
23. Bovine spongiform encephalopathy.
24. Principles of diagnosis of infectious diseases.
25. Type of vaccines and their use to control infectious diseases.
BOTTARELLI E. e Ostanello F.: Epidemiologia. Teoria ed esempi di medicina veterinaria.
SCATOZZA F., FARINA R.: Trattato di malattie infettive degli animali. UTET, Torino, 1999. .
During the lessons the principles of epidemiology and prevention adding to theoretical principles to cope field problems will be addressed. Along with the practical lessons, the student will have to deal of problems in field conditions.
Assessment methods and criteria
The assessment of the objectives of the course involves a written examination, with 6 open questions.
The aim is to ascertain if the student has a good knowledge of the topics of the course, has good communication skills and is able to use it autonomously.
The result is assigned to the overall assessment of the answers from the student. The final mark is expressed in thirtieths.
Students with specific learning disability, certified according to the law n. 170/2010 will be granted the benefits provided by law.