Prevention PDF

BY Ahmed Mohamed Khair Shabib Ibrahim e-mail: [email protected]; [email protected]  The goals of medicine are to promote health, to preserve health, to restore health when it is impaired, and to minimize suffering and distress  These goals are embodied in the word "prevention"...

BY Ahmed Mohamed Khair Shabib Ibrahim e-mail: [email protected]; [email protected]  The goals of medicine are to promote health, to preserve health, to restore health when it is impaired, and to minimize suffering and distress  These goals are embodied in the word "prevention"  Actions aimed at eradicating, eliminating or minimizing the impact of disease and disability, or if none of these are feasible, retarding the progress of the disease and disability.  The concept of prevention is best defined in the context of levels, traditionally called primary, secondary and tertiary prevention. A fourth level, called primordial prevention, was later added.  Successful prevention depends upon: ◦ Aknowledge of causation ◦ Dynamics of transmission ◦ Identification of risk factors and risk groups ◦ Availability of prophylactic or early detection and treatment measures, ◦ Organization for applying these measures ◦ Continuous evaluation and development of procedures applied  BEINGS Biological factors and Behavioral Factors Environmental factors Immunologic factors Nutritional factors Genetic factors Services, Social factors, and Spiritual factors [JF Jekel, Epidemiology, Biostatistics, and Preventive Medicine, 1996]  Leavell & Clark’s Levels of Prevention Stage of disease Level of prevention Type of response Pre-disease Primary Prevention Health promotion and Specific protection Latent Disease Secondary prevention Pre-symptomatic Diagnosis and treatment Symptomatic Disease Tertiary prevention Disability limitation for early symptomatic disease Rehabilitation for late Symptomatic disease Levels of Prevention Primordial prevention Primary prevention Secondary prevention Tertiary prevention  Primordial prevention consists of actions and measures that inhibit the emergence of risk factors as environmental, economic, social, and behavioral conditions etc.  It is the prevention of the emergence or development of risk factors in countries or population groups in which they have not yet appeared  For example, many adult health problems (e.g., obesity, hypertension) have their early origins in childhood, because this is the time when lifestyles are formed (for example, smoking, eating patterns, physical exercise).  In primordial prevention, efforts are directed towards discouraging children from adopting harmful lifestyles  The main intervention in primordial prevention is through individual and mass education  Primary prevention can be defined as the action taken prior to the onset of disease, which removes the possibility that the disease will ever occur.  It signifies intervention in the pre- pathogenesis phase of a disease or health problem.  Primary prevention may be accomplished by measures of “Health promotion” and “specific protection”  It includes the concept of "positive health", a concept that encourages achievement and maintenance of "an acceptable level of health that will enable every individual to lead a socially and economically productive life".  Primary prevention may be accomplished by measures designed to promote general health, and quality of life or by specific protective measures.  Primary prevention Achieved by Health promotion Specific protection Health education Immunization and seroprophylaxis Chemoprophylaxis Environmental modifications Use of specific nutrients or supplemen. Nutritional interventions Life style and behavioral changes Protection against occupational hazards Safety of drugs and foods Control of environmental hazards  Health promotion is “ the process of enabling people to increase control over the determinants of health and thereby improve their health”.  The WHO has recommended the following approaches for the primary prevention of chronic diseases where the risk factors are established: A. Population (mass) strategy B. High -risk strategy  “Population strategy" is directed at the whole population irrespective of individual risk levels.  For example, studies have shown that even a small reduction in the average blood pressure or serum cholesterol of a population would produce a large reduction in the incidence of cardiovascular disease  The population approach is directed towards socio- economic, behavioral and lifestyle changes  The high -risk strategy aims to bring preventive care to individuals at special risk.  This requires detection of individuals at high risk by the optimum use of clinical methods.  It is defined as “ action which halts the progress of a disease at its incipient stage and prevents complications.”  The specific interventions are: early diagnosis (e.g. screening tests, and case finding programs….) and adequate treatment.  Secondary prevention attempts to arrest the disease process, restore health by seeking out unrecognized disease and treating it before irreversible pathological changes take place, and reverse communicability of infectious diseases.  It thus protects others from in the community from acquiring the infection and thus provide at once secondary prevention for the infected ones and primary prevention for their potential contacts.  Secondary prevention attempts to arrest the disease process, restore health by seeking out unrecognized disease and treating it before irreversible pathological changes take place, and reverse communicability of infectious diseases.  It thus protects others from in the community from acquiring the infection and thus provide at once secondary prevention for the infected ones and primary prevention for their potential contacts.  WHO Expert Committee in 1973 defined early detection of health disorders as “ the detection of disturbances of homoeostatic and compensatory mechanism while biochemical, morphological and functional changes are still reversible.”  The earlier the disease is diagnosed, and treated the better it is for prognosis of the case and in the prevention of the occurrence of other secondary cases.  It is used when the disease process has advanced beyond its early stages.  It is defined as “all the measures available to reduce or limit impairments and disabilities, and to promote the patients’ adjustment to irremediable conditions.”  Intervention that should be accomplished in the stage of tertiary prevention are disability limitation, and rehabilitation.  Disease Impairment Disability Handicap  Impairment is “any loss or abnormality of psychological, physiological or anatomical structure or function.”  Disability is “any restriction or lack of ability to perform an activity in the manner or within the range considered normal for the human being.”  Handicap is termed as “a disadvantage for a given individual, resulting from an impairment or disability, that limits or prevents the fulfillment of a role in the community that is normal (depending on age, sex, and social and cultural factors) for that individual.”  Rehabilitation is “ the combined and coordinated use of medical, social, educational, and vocational measures for training and retraining the individual to the highest possible level of functional ability.”  Rehabilitation Medical Vocational Social Psychological rehabilitation rehabilitation rehabilitation rehabilitation  Strategy for Prevention Identify Populations Modify Existing at High Disease Risk Intervention (based on demography / family history, Programs host factors..) Assess Evaluate Exposure Intervention Programs Conduct Research on Apply Mechanisms (including the study of Population-Based genetic susceptibility) Intervention Programs The term disease control describes ongoing operations aimed at reducing: ◦The incidence of disease ◦The duration of disease and consequently the risk of transmission ◦The effects of infection, including both the physical and psychosocial complications ◦The financial burden to the community.  Control activities focus on primary prevention or secondary prevention, but most programs combine both. control elimination eradication  Between control and eradication, an intermediate goal has been described, called "regional elimination"  The term "elimination" is used to describe interruption of transmission of disease, as for example, elimination of measles, polio and diphtheria from large geographic regions or areas  Regional elimination is now seen as an important precursor of eradication  Eradication literally means to "tear out by roots".  It is the process of “Termination of all transmission of infection by extermination of the infectious agent through surveillance and containment”.  Eradication is an absolute process, an "all or none" phenomenon, restricted to termination of an infection from the whole world. It implies that disease will no longer occur in a population.  To-date, only one disease has been eradicated, that is  Monitoring is "the performance and analysis of routine measurements aimed at detecting changes in the environment or health status of population" (Thus we have monitoring of air pollution, water quality, growth and nutritional status, etc).  It also refers to on -going measurement of performance of a health service or a health professional, or of the extent to which patients comply with or adhere to advice from health professionals.  surveillance means to watch over with great attention, authority and often with suspicion  According to another, surveillance is defined as "the continuous scrutiny (inspection) of the factors that determine the occurrence and distribution of disease and other conditions of ill-health"  The main objectives of surveillance are: A. To provide information about new and changing trends in the health status of a population, e.g., morbidity, mortality, nutritional status or other indicators and environmental hazards, health practices and other factors that may affect health B. To provide feed-back which may be expected to modify the policy and the system itself and lead to redefinition of objectives, and C. To provide timely warning of public health disasters so that interventions can be mobilized.  Control Cases Contacts Carriers Community Diagnosis Notification Standard Isolation Strict Listing Environmental control Protective Detection Disinfection Observation Health Education Treatment Immunization Specific Prevention Follow up Chemoprophylaxis Drastic Measures Release Epidemiological Investigation 1. Diagnosis 2.Notification: It is required by low to notify some communicable diseases. In this regard, such diseases are classified into three main categories: A. Class I: Obligatory notification to central authorities which notify the WHO. Diseases in this class are Quarantinable diseases (Cholera, Yellow fever, and plague). B. Class II: Obligatory notification to health authorities and hospital isolation is preferred. Diseases in the class include: CS meningitis, polio, typhoid and paratyphoid C. Class III: Notification is highly desirable but hospital isolation is not obligatory. Diseases in this class include: Measles, German measles Pertussis, mumps, tetanus and influenza. 3. Isolation: May be in hospital or in home according to the class to which the disease belongs. In general the isolation unit should be equipped with its own toilet facilities, or at least with running water. A two to four-bed unit can be used for several patients with the same kind of infection. All isolation units must be provided with soap and hand scrub brush (not for patient use), paper towels, step-on refuse can be covered with disposable plastic liner, plastic covers on mattresses and pillows, and a supply of masks, gowns, and gloves on a table outside door to the unit Period of isolation depends on the period of communicability of the disease and on the developing of convalescent carrier state. 4.Release: Means permission of the case to leave the isolation place and return to school, work or other activities. Requirements 1- Recovery of the case: become clinically free. 2- Satisfactory general condition, especially after debilitating diseases. 3- Cessation of infectivity in diseases having a convalescent carrier, e.g. enterica, diphtheria, cholera, polio. This can be judged by: Bacteriological examination of stools, urine and throat and nose swabs, after recovery and every other day, to get 3 successive negative results. After an arbitrary period of time which is known to cover the period of potential risk of infectivity, especially in viral diseases where mass examination for isolation of the causative organism is impractical. Why three negative results are required? - To confirm elimination of infection. - To safeguard against sampling and technical defects. - To exclude possibility of intermittent discharge of organisms. 4. Treatment  Category, Incubation period, and seasonality of disease Name of group Name of disease Incubation period Season Quarantinable Cholera 5 days Late summer Diseases Yellow fever 6 days After rainfall Plague 6 days warm months (March-July) Smallpox (eradicated) 14 days Winter and early spring Droplet infection TB 6 weeks winter and spring Measles 10 days winter and spring German measles 14-21 days winter and spring Mumps 18 days winter and spring Whooping cough 7 days winter and spring Pneumonia 1-3 days winter and spring Cerebrospinal meningitis 5 days winter and spring Food-born disease Typhoid 2 weeks summer Poliomyelitis 7-21 days summer and early autumn Bacillary dysentery 1-7 days summer and early autumn Infective hepatitis 2-6 weeks autumn and winter Food poisoning (staph) 6-12 hours autumn and winter Botulism 18 hours autumn and winter Food infection (salmonella) 6-48 hours autumn and winter Venereal and Syphilis 10 days - 10 weeks autumn and winter contact diseases Gonorrhea 3-9 days autumn and winter Tetanus 4 days - 4 weeks autumn and winter Parasitic diseases Bilharziasis 2-7 weeks Ankylostomiasis 4-6 weeks Ascariasis 8 weeks Amoebiasis 2-3 weeks Malaria 12-14 days Thank You