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EPIDEMIOLOGY, INFECTIOUS DISEASES. Department of Microbiology and Infectious Diseases Budapest, XIV. Hungária krt. 23-25. Telephone: 251.9900 Internal phone: 8090, 8091 Fax: 251.9260 E-mail: Fodor.Laszlo@aotk.szie.hu. Department of Microbiology and Infectious Diseases Lectures - PowerPoint PPT Presentation



  • Department of Microbiology and Infectious DiseasesBudapest, XIV. Hungria krt. 23-25.Telephone: 251.9900Internal phone: 8090, 8091Fax: 251.9260E-mail: Fodor.Laszlo@aotk.szie.hu

  • Department of Microbiology and Infectious Diseases

    LecturesBakonyi, Tams: Associate ProfessorFodor, Lszl: ProfessorMakrai, Lszl: Associate ProfessorTuboly, Tams: ProfessorVarga, Jnos: Professorinvited speakers

  • Department of Microbiology and Infectious Diseases

    Plenary practicalsBakonyi, Tams: Associate ProfessorFodor, Lszl: ProfessorHornyk, kos: Head of DepartmentMakrai, Lszl: Associate ProfessorTuboly, Tams: ProfessorVarga, Jnos: Professor

    Diagnostical practical4 weeks

  • Importance of infectious diseases

    all areas of veterinary medicinegreat economic impact (avian influenza 20 bn $)trade of animal and animal productszoonosesfood hygiene, food safety 25% of human death cases is because of infective agents

  • Subject of Epidemiology, infectious diseases Structure lectures plenary practicals (from 10th October, 2011) practice at diagnostic institute midterm exam (24th October, 21st November) Content general epidemiology diseases caused by viruses diseases caused by prions diseases caused by bacteria

  • LiteratureHagan and Brunners Microbiology and Infectious Diseases. 8th Ed. Comstock Publishing Associates 1988.Kahn (Ed.): The Merck Veterinary Manual. 10th Ed. Merck & Co. 2010. www.merckvetmanual.comhttp://www.oie.intStraw, B. et al. (Eds.): Diseases of swine. 9th Ed. Blackwell. 2006.Saif, Y.M. (Ed.Ch.): Diseases of poultry. 12th Ed. Blackwell. 2008.Radostits, O.M. (Ed.): Veterinary Medicine 10th Ed. Elsevir. 2007.


    Varro (2nd cent B.C.): living agentsFracastoro (16th cent.) contagium vivumLeeuvenhoek (17th-18th cent.): microscopePollender (19th cent.): bacteria in the blood of animals with anthraxPasteur-Koch (19th-20th cent.) Ivanovsky (19th cent.): virusLffler and Frosch (1897): foot and mouth disease virusJenner (1796): poxMechnikov (1884): phagocytosisBehring (1890): antibodies in the blooderadication of infectious diseases

  • Infectious diseaseagent (lower ranked)host (higher ranked)exposition - dispositionphases of infection

  • Sources of infectionsource: generally infected animals / humans directindirect excretions, secretions (blood, faeces, urine, saliva, milk, semen,)products of animal origin (meat, milk, skin, wool, hair) drinking water, feedsoil, environment aerogenic arthropods iatrogenic infections nosocomial

  • Transmission of diseasesvertical germinative intra uterine galactogenhorizontal


  • Infectionways of infection per os, intra nasal, genital tract, udder conjunctiva, per cutan, wound optimal entrancesource of infection: animal (carrier), environment, feed, water, etc.

    Forms of infectionreinfectionexacerbationsuperinfectionsecondary infectionmixed infection

  • Outcome of the infection (agent host environment)

    agent relationship of the agent and the host (pathogenicity, virulence) amount of the agent way of infectionhost species, age species related resistance non specific resistance specific resistanceenvironment nutrition management

  • Outcome of the infection (agent host - environment)

    Agent host-parasite relationship normal microflora pathogenicity (euryxen / stenoxen, obligate / facultative pathogen) virulence (virulence factors, MLD, LD50, change of the virulence) invasiveness (intra cellular, extra cellular) amount of the agent way of infection (optimal!) Henle-Koch postulates

  • Outcome of the infection (agent host environment)

    Host species, age (species specific resistance) race, individual resistance (lines) production (feeding, laying) non specific resistance skin, mucous membranes, excretions (HCl, fatty acids, bile, etc. macrophag-phagocyte system (MPS) complement, properdin, opsonin IL, IF, TNF specific resistance passive immunity (natural, induced) active immunity (natural, induced)

  • specific resistancehumoral resistance (IgA, IgG etc.)cellular resistance (i.c. bacteria, viruses)effect of immune suppression (toxicosis, medicine, micotoxins, some agents, parturation etc.)foetal immune reaction (hierarchy, age)immune reaction of newborns (age related)calf: Ig 4-32 dayscalf, piglet: local immune reaction immediately (disappears, no immune memory)cellular immune reaction: 0-2 weeks weaker

  • Outcome of the infection (agent host environment)

    Environment survival in the environment environmental effects on animals predisposes to facultative pathogens nutrition management technology (weaning, grouping, treatment, castration, sheering, transport)physiological effects, use of animals

  • Course of an infectious disease

    local infectioninfections of different organs (localised)generalised infectionsincubation: infection, colonisation, replicationgeneralisation: spreading (blood, lymphatic vessels, perineural)foetus: resorption, embryonic death, abortionteratogenicdecreased resistancetolerated infectionsmanifestation: clinical signs, lesions (virulence factors)

  • Course of infectious diseases caused by viruses

    replication at the place of entry and in the regional lymph nodelocalisation by macrophagesreplication in infected macrophages, lymphocytes, blood (viraemia)replication in lymphoid cells: immune suppression, damage of blood vesselssecondary replication in tissuesdamage of cells: clinical signsreactive inflammation, allergic reactions clinical signs

  • Start and course of infectious diseases

    Course of the diseaseincubation timecourse of an infection in timeperacuteacutesubacutechronic

    Outcome of the disease: recovery (full or partial), carrierdeath

  • Infections without clinical signs

    forms of infections without clinical signsabortive infectioninapparent (sub clinical) infectionpersistent infection (virus)latent infection (virus)tolerated infection (virus)importance of infections without clinical signs

  • Epidemiology of infectious diseases

    Characteristic of infectious diseasesinfectious diseasescontagious diseasessoil infections

    Statistical evaluation of infectious diseasesmorbiditymortalitylethalityincidenceprevalence

  • Analysing methods of infectious diseases

    data collection to diagnostic workmonitoringsurveillance (passive, active)screening control of hypothesisstatistical methodsblind examinations

  • Extension of infectious diseasesendemic diseases (enzootia)epidemic diseases (epizootia)pandemic diseases (panzootia)


    International cooperation regarding infectious diseasesOIE (Office International des Epizooties, World Organisation for Animal Health) 1924.FAO (Food and Agricultural Organisation) 1948.WHO (World Health Organisation) 1948.

  • Factors influencing infections

    geographical factors (island, desert, mountain, river, soil)climatic factors (sunshine, wind, vapour content, season)management (overcrowding, mixing, contact, draught, NH3)nutrition (pasture, stable, starvation) transport (road, rail, harbour)biological factors (mating, leave of the offspring)

  • Diagnostics of infectious diseases

    complexepidemiological dataclinical signspathological lesionsallergic examinationlaboratory examinations (diagnostic institutions)evaluation, diagnosis

  • Diagnostics of infectious diseases

    epidemiology clinical signs pathological lesionsallergic tests (tuberculin, mallein)laboratory diagnosissampling, letterhistological examinationmicroscopic examination (smear)electron microscopic examinationisolation (medium cell culture egg laboratory animal)serological testsclassical: agglutination, precipitation, elfo, PAGE, CFTvirus serology: VN, HAImarked immunological methods: IF, ELISA, RIA, IRMA

  • Diagnostics of infectious diseases

    cellular testslymphocyte stimulation testimmune rosette formationcytotoxic reactionmacrophage migration g-interferon testmethods detecting nucleic acids (DNA hybridisation, PCR)more diagnostic methods have to be usedcomplex evaluation

  • Treatment of diseased animals

    aetiological treatmentsymptomatic treatmentbacteria: antibacterial treatment (appropriate medicine)individual / mass treatmenttreatment of certain diseases is not allowedsome chronic diseases cannot be treated or treatment is not reasonableprevention of complications (diseases caused by viruses)hyperimmune serum

  • Prevention and control of infectious diseases

    veterinary administration, rulesgeneral rulesspecific measuresimmune prophylaxischemoprophylaxis

  • Prevention and control of infectious diseases

    rules, veterinary administrationinternational transport, certificatesimport restrictionsquality requirementslocalisation

  • Prevention and control of infectious diseases

    general rulesall in, all out, disinfectionisolated keeping of different animal species / age groupsclosed keeping, limited traffic (personal, vehicles, avoiding mixing)isolation from wild animals, rodents, birdsrendering dead animals, wasterules of hatching, transport of day-old chickenexcluding carrier people

  • Prevention and control of infectious diseases

    veterinary administrationgeneral rulesspecific rulesspecific measures concerning a certain diseaseimmune prophylaxispassive immunisationactive immunisationchemoprophylaxis

  • Immune prophylaxisPassive immunisationhyperimmune serummaternal immunity epitheliochorial: colostrum syndesmochorial: mainly colostrum endotheliochorial: diaplacentar + colostrum immuno globu