Learning objectives
Knowledge and understanding.
At the end of the module the student is expected to know and
understand:
the role and purposes of epidemiology; the scientific method and the
epidemiological approach to the quantitative analysis of the
circumstances under which health events occur in animal populations;
the criteria for characterizing the causality of associations; the
applications of epidemiology in evaluating the efficacy and efficiency of
prophylactic and therapeutic treatments and diagnostic tests.
- Applying knowledge and understanding.
At the end of the module the student is expected to be able to: determine
the extent and impact of a disease; identify risk factors; compare the
different research strategies and the different epidemiological study
designs, evaluating their strengths and weaknesses. Furthermore, the
student is expected to be able to critically evaluate the scientific
literature concerning the subject.
- Making judgements.
trasmissibili. Ciclo di una malattia trasmissibile. Infezione latente e stato
di portatore. Trasmissione orizzontale e verticale, diretta e indiretta. Tipi
di ospite. Vettore meccanico e biologico. Fattori associati alla diffusione
delle infezioni. Diffusione delle infezioni e caratteristiche dell'ospite:
recettività e contagiosità. Diffusione delle infezioni e caratteristiche
dell'agente. Diffusione delle infezioni ed efficienza del contatto. Vie di
infezione. Modalità di trasmissione. Trasmissione a lunga distanza di
agenti di malattia. Trasmissione delle malattie per via verticale. Strategie
di mantenimento e di sopravvivenza dell'agente.
Obiettivi per lo sviluppo sostenibile
Codice Descrizione
At the end of the module the student is expected to be able to apply the
skills acquired in order to make decisions based on evidence, in
consideration of clinical, economic and possibly political aspects, in a
defined epidemiological context.
- Communication skills.
At the end of the module the student is expected to have acquired the
ability to communicate with adequate language skills and to be able to
present the topics in a clear, linear and coherent manner.
- Learning skills.
At the end of the module the student is expected to have developed skills
that allow independent learning through the critical evaluation of the
scientific literature concerning the subject.
Prerequisites
First year course “Applied physics, basic mathematics for biomedical
sciences, Informatics”.
Basic competence in using Excel.
Desirable technical requirements: internet access and possession of a PC
with Office package.
Course unit content
Study of the methods applied to the understanding of the epidemiology
of diseases of veterinary interest.
Full programme
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. Basics of computational epidemiology. Descriptive and
analytical epidemiology. Evidence based medicine, example of
systematic review and meta-analysis, the forest plot.
2. Tasks and aims of epidemiology. Tasks of veterinary epidemiology.
Natural history of disease. Classic iceberg concept of infection.
Prevention, control and eradication of diseases. Basic reproduction
number and herd immunity. The aims of epidemiological studies.
Analytical studies for demonstrating causality. Observational (cohort,
case-control and cross-sectional) and experimental studies (uncontrolled,
randomized and non-randomized controlled), prospective and
retrospective 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. Confounding and effect modification.
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. Prevalence rate, relative
risk and odds ratio. Linear simple regression.
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.
Standardization 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.
Bibliography
BOTTARELLI E., OSTANELLO F. (2011). Epidemiologia. Teoria ed esempi di
medicina veterinaria. Edagricole, Milano;
oppure (disponibile online):
BOTTARELLI E. Quaderno di Epidemiologia Veterinaria
(http://www.quadernodiepidemiologia.it);
testi di consultazione:
PFEIFFER D.U. (2002). Veterinary Epidemiology - An Introduction (PDF
reperibile liberamente online);
THRUSFIELD M. (2018). Veterinary epidemiology. Wiley Blackwell
(disponibile presso la biblioteca di Medicina Veterinaria);
LOPALCO P.L., TOZZI A.E. (2003). Epidemiologia facile. Il Pensiero
Scientifico Editore, Roma (disponibile presso la biblioteca di Medicina
Veterinaria);
SIGNORELLI C. (2000) Elementi di metodologia epidemiologica. Società
Editrice Universo, Roma, V ed. (disponibile presso la biblioteca di
Medicina Veterinaria);
BEAGLEHOLE R., BONITA R., KJELLSTROM. (1997). Epidemiologia di base.
Edizione italiana a cura di G. Agazzotti, Editoriale Fernando Folini,
Casalnoceto (disponibile presso la biblioteca di Medicina e Chirurgia).
Teaching methods
The lectures will be carried out through the prevalent use of slideshow or
multimedia presentations.
Practical teaching will be carried out partly independently through guided
exercises using a spreadsheet.
Assessment methods and criteria
Written exam, lasting one hour, at the end of the module.
Composition of the written test:
Two open questions. The maximum score achievable for each question is
5.
Four questions with multiple choice answers. The score is assigned
according to the following criteria: 2 points for correct answers; 0 points
for the answers not given; there is no penalty for incorrect answers.
Two exercises. The maximum score achievable for each exercise is 6.
The student can use a calculator (no smartphone, smartwatch or PC)
during the test.
The final score is given by the sum of the scores acquired for each
question/exercise. The student must achieve a minimum score of
eighteen to pass the exam. The use of appropriate terminology will be
taken into account in the evaluation.
Students with certified disabilities pursuant to article 16 of law n.
104/1992 or learning disabilities (law n. 170/2010), will be provided with
proper specific support and additional times.
Other information
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