Viorel PRISACARU GENERAL EPIDEMIOLOGY WITH MEDICINE BASED ON EVIDENCE CHIŞINĂU - 2015 1 Nicolae Testemitanu State University of Medicine and Pharmacy Epidemiology Department Viorel PRISACARU Translated by Angela PARASCHIV GENERAL EPIDEMIOLOGY WITH MEDICINE BASED ON EVIDENCE Chişinău - 2015 2 CZU 616-036.22:001.87(075.8) Viorel Prisacaru General Epidemiology with medicine based on evidence Translation of the course book „Epidemiologie generală. Bazele medicinei prin dovezi”, Chisinau-2012. Author- Viorel Prisacaru Approved at Central Metodic Council of SUMPh “Nicolae Testemitanu”, meenutes nr. 05 from 11.04.2012. Translated by Angela Paraschiv; English copy corrector –Liudmila Martinenko. Reviewers: V.Chicu – Ph.D. in medicine, associate professor Ad.Cotelea – Ph.D. in medicine, associate professor The book concerns such subjects as the mechanisms of emergence and spread of pathological phenomena in human population and measures of their prevention and control. Particular attention is given to the method of epidemiological studies in infectious and noninfectious diseases and the use of principles medicine of based on evidence in decisions making and assessing the effectiveness and safety measures for prevention and control of human diseases, including diagnosis and treatment. It contains elements of classical epidemiology, clinical epidemiology, epidemiological bioethics and health promotion. The book is intended for students, physicians, residents, and physicians of all specialties interested in making correct decisions and evaluation of diseases. General Epidemiology with medicine based on evidence -Viorel Prisacaru. - Chişinău. Edition …………… , 2012. - ....... p. ....... ex. com…… ISBN …… CZU 616-036.22:001.87(075.8) ISBN 3 C O N T E N T INTRODUCTION V. Prisacaru 9 HISTORY AND TRANSFORMATION IN EPIDEMIOLOGY 11 V. Prisacaru DEFINITION AND SUBJECT OF STUDY OF MODERN 19 EPIDEMIOLOGY V. Prisacaru STRUCTURE AND CONTENT OF EPIDEMIOLOGICAL METHODS 24 OF INVESTIGATION V. Prisacaru 1. Method of observation and description 24 2. Experimental method 25 3. Laboratory method 25 4. Statistical method 28 4.1. Indicators of health status of the population 28 4.1.1. Level indicators 29 4.1.1.1. Morbidity 29 4.1.1.2. Mortality 30 4.1.1.3. Lethality 30 4.1.1.4. Fatality 30 4.1.1.5. Fertility 30 4.1.1.6. Life expectancy 31 4.1.2. Indicators of factors 31 4.2. Epidemiological indicators 31 4.2.1. Incidence 31 4.2.2. Prevalence 31 4.2.3. Statistic indices of frequency 32 4.2.3.1. absolute value 32 4.2.3.2. cumulative indices 32 4.2.3.3. Intensive indices 34 4.2.3.4. Extensive indices 34 4.2.3.5. Demonstration indices 35 4.2.3.6. Proportions 36 TYPES OF STUDIES IN EPIDEMIOLOGICAL RESEARCH 37 V. Prisacaru 1. Observational studies 37 1.1. Descriptive studies 37 1.1.1. Individual descriptive studies 38 1.1.2. Population descriptive studies 39 1.2. Analytical studies 41 1.2.1. ”Cause-effect” phenomena 41 1.2.2. Types of analytical studies 42 1.2.2.1 Ecological or correlation studies 43 4 1.2.2.2. Case control studies 46 1.2.2.3. Cohort studies 48 2. Experimental studies 50 2.1. Experimental controlled studies 50 2.1.1. Randomized controlled trials 51 2.1.2. Experimental studies of land 52 2.1.3. Uncontrolled experimental studies 52 2.1.4. Natural experiment 52 2.1.5. Modelling of epidemic process 52 3. Epidemiological transversal studies 52 4. Longitudinal epidemiological studies 53 4.1 Retrospective studies 53 4.2. Prospective studies 54 5. Meta-analysis 54 6. Determining the risk 54 6.1. Absolute risk (R) 55 6.2. Attribuable risk (RA) 56 6.3. Relative risk (RR) 56 6.4. Odds ratio (OR) 56 7. Epidemiological investigation 57 7.1. Epidemiological investigation of outbreaks of infectious diseases with 57 single cases 7.2. Epidemiological investigation based on questionnaire 58 8. Epidemiological analysis of morbidity 59 8.1. Retrospective analysis 59 8.1.1. Stages of retrospective epidemiological analysis 59 8.1.1.1. Analysis of multiannual dynamic of morbidity 59 8.1.1.2. Analysis of growth of morbidity in annual dynamic 60 8.1.1.3. Analysis of geographical distribution of morbidity 61 8.1.1.4. Determining the risk group 62 8.2. Operative epidemiological analysis 64 8.3. Planning of intervention measures 64 9. Screening 64 10. Determination of the size of the studied group 65 GENERAL EPIDEMIOLOGY OF INFECTIOUS DISEASES 67 V. Prisacaru 1. Epidemic process. Regularities of maintenance, development and 67 decreasing of epidemic process 1.1. Basic principles 67 1.2. Concept, structure and mechanism of development of epidemic process 67 1.2.1. The concept and basic structure of epidemic process 67 1.2.2. Source of pathogens 69 1.2.2.1. Source of pathogens in anthroponosis 70 1.2.2.1.1. Infectious patients as a source of pathogens. Epidemiological 71 importance of different forms and periods of infection. 5 1.2.2.1.2. Carriers of pathogens. Classification, epidemiological importance. 73 1.2.2.2. Source of pathogens in zooanthroponosis 74 1.2.2.3. Source of pathogens in sapronosis 76 1.2.3. The mechanism of transmission of pathogens 81 1.2.4. Factors and transmission routes of pathogens 86 1.2.5. Population receptivity 90 1.2.6. Manifestations of epidemic process 92 THE SYSTEM OF PROPHYLACTIC AND CONTROL MEASURES IN 94 COMMUNICABLE DISEASES V. Prisacaru 1. Measures aimed to neutralize the source of pathogens 94 1.1. Measures directed to the source of pathogens in anthroponosis 94 1.2. Measures directed to the source of pathogens in zooanthroponosis 96 1.2.1. Deratization V. Ţurcan, V. Prisacaru 96 1.2.1.1. Rodent control measures 96 2. Measures aimed to neutralize the transmission mechanism 98 2.1. Disinfection V. Ţurcan, V. Prisacaru 98 2.1.2. Types of desinfection 98 2.1.2.1. Methods of disinfection 99 2.1.2.1.1. Physical method 99 2.1.2.1.2. Chemical method 101 2.1.2.1.2.1. Classification of disinfectant preparations 102 2.1.2.1.2.2. Factors that influence the effectiveness of disinfection 103 2.1.2.1.2.3. Forms and methods of application 105 2.1.2.1.2.4. Sensitivity/resistance of microorganisms to disinfectants 106 2.1.2.1.2.5. Requirements to terminal disinfection 107 2.1.2.1.2.6. Requirements to organization of current disinfection at home 107 2.2 Sterilization V. Ţurcan, V. Prisacaru 108 2.2.1 Methods of sterilization 108 2.2.1.1 Physical method 109 2.2.1.1.1 Sterilization by heat 109 2.2.1.1.2 Sterilization by steam under pressure in autoclave 109 2.2.1.1.3 Sterilization by prolonged boiling 110 2.2.1.1.4 Low-temperature sterilization technologies 110 2.2.1.1.5 Sterlization of water for surgical washing 111 2.2.1.1.6 Sterilization by ionizing radiation 111 2.2.1.1.7 Sterilization by filtration 111 2.2.1.1.8 Sterilization by microwaves 111 2.2.1.2 Chemical sterilization 111 2.2.1.2.1 Chemical sterilization with strong disinfectants 111 2.2.1.2.2 Gaseous sterilization 112 2.2.2 Sterilization of medical items 112 2.2.3 Central sterilization department 114 2.3. Disinsection V. Ţurcan, V. Prisacaru 114 2.3.1. Methods, sources and means of disinsection 115 2.3.2. Forms of insecticides used in practice 116 6 3. Immunoprophylaxis of infectious diseases V. Prisacaru 117 3.1.1. Types of vaccines 117 3.1.1.1. Live corpuscular vaccines 117 3.1.1.2. Inactivated corpuscular vaccine 118 3.1.1.3. Subunit vaccines and split vaccines 118 3.1.1.4. Toxoids 119 3.1.1.5. Recombinant vaccines 119 3.1.1.6. Synthetic vaccines 119 3.1.1.7. Associated vaccines 120 3.1.2. Ensuring quality and safety of vaccines 121 3.1.2.1. The national supervisory authorities of vaccines 121 3.1.2.2. Conditions to vaccines as biological product 121 3.1.2.3. Requirments for the vaccine to be administrated 121 3.1.3. Storage conditions 122 3.1.4. Indications for vaccination 122 3.1.5. Calendar of vaccination 123 3.1.6. Basic principles in organizing and administering of vaccines 124 3.1.7. Contraindications to vaccination 127 3.1.7.1. Absolute contraindications 127 3.1.7.1.1. Serious safe reactions 127 3.1.7.1.2. Vaccine cell pertussis component 127 3.1.7.1.3. Vaccines produced from chicken embryos or containing 127 neomycin 3.1.7.1.4. Live vaccines 127 3.1.7.2. Temporary contraindications 128 3.1.7.3. False contraindications 128 3.1.8. The methods of vaccines administration 128 3.1.8.1. Parenteral administration 128 3.1.8.2. Enteral ("orally, per os") 130 3.1.8.3. Intranasal administration 130 3.1.9. Adverse reactions after vaccination 130 3.1.9.1. General adverse reactions after vaccination 131 3.1.9.2. Undesirable side effects after vaccination 132 3.1.10. Reactions associated with the program 133 3.1.11. Vaccination of children with allergic diseases 133 3.1.12. Vaccination of children with neurological conditions 134 3.1.13. Vaccination during pregnancy 135 3.1.14. Vaccination of persons with HIV/AIDS 136 3.1.15. Planned vaccination 136 3.1.16. Features of vaccines included in the immunization schedule 139 3.1.16.1Vaccine against tuberculosis BCG (Bacille Calmette – Guérin) 139 3.1.16.2. Vaccine against hepatitis B (Hep B) 141 3.1.16.3.