CONCEPTS IN PUBLIC HEALTH AND PREVENTIVE MEDICINE

1. CONCEPTS IN PUBLIC HEALTHAND PREVENTIVE MEDICINE SHORT TEXTBOOK OFPUBLIC HEALTH MEDICINEFOR THE TROPICS 4th edition A d e t o k u n b o O . L u c a s dr.suzanyousif

2. There is a confusing in the nomenclature that is used to describepublic health and its component elements. The oldestterm, hygiene, embodied the early knowledgeabout value of sanitation and personal cleanliness. • As knowledge grew, the termhygiene was felt to be too narrow and a broaderterm public health was used more widely. The termpublic health did not survive unchallenged as newterms were introduced to define special aspects ofthe discipline. Some used the term ‘preventive medicine’; others preferred ‘social medicine’, ‘community medicine’, or ‘community health’. • Charles-Edward Armory Winslow is a leading figure in the development of the modern study of public health. His definition of public health, developed almost a century ago, is as follows: • “Public health is the science and art of preventing disease, prolonging life and promoting health through the organized efforts and informed choices of society, organizations, public and private communities, and individuals.” • In a modern interpretation of Winslow’s definition, Beagleholeand Bonita (1997) identified the following essential elements of modern public health: • ■ collective responsibility; • ■ prime role of the state in protecting and promoting the public’s health; • ■ partnership with the population served; • ■ emphasis on prevention; • ■ recognizing underlying socio-economic determinants of health and disease; dr.suzan yousif

3. THE DIMENSIONS OF PUBLICHEALTH It would be useful to explore the concepts containedin the four terms that are commonly used todescribe different aspects of public health: ■ preventive medicine; ■ social medicine; ■ community health; ■ community medicine. • PREVENTIVE MEDICINE • Prevention is better than cure is one of the primemessages of public health. It differentiates publichealth from the clinical disciplines that are primarilyinvolved with the care of the sick, whilstpublic health emphasizes the avoidance of illness. • Prevention was initially construed narrowly interms of protective measures like vaccination andimproved nutrition that target only healthy peoplewith the aim of preventing the onset of disease. • This concept was extended to cover the early diagnosisand treatment of sick persons with the aim ofpreventing advanced diseases and in the case ofcommunicable diseases, in preventing the spreadwithin the community. • A further extension of thedefinition covers the treatment of sick individualsaimed at reversing damage and restoring function. • This concept led to the classification of preventioninto three levels later to be differentiated into fivestages . dr.suzan yousif

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5. SOCIAL MEDICINE • ‘The poor die young’ • The rise of social medicine coincided with increasingrealization of the links between social statusand the health of individuals and communities. • Statistical analyses of mortality and morbidity datashow strong correlation between the social stratificationin society and the pattern of health and disease. • Numerous studies in many countriesconfirm this association and point to the need forsocial interventions to complement biomedical toolsin improvingthe health of the deprived sections ofthe community. • The objective of social medicine isto identify the socialdeterminants of health anddisease in the community and to devise mechanismsfor alleviating suffering and ill health throughsocial policies and actions. Social medicine is basedon certain fundamental assumptions: • Health as a birthright. Everyone has the right toenjoy the highest possible level of health. • The responsibility of the state. It is the duty ofgovernments to ensure that the people have thebasic elements that would enable families andindividuals to maintain good health and thatthey have access to good quality health care. • Development and health are inter-related. Goodhealth promotes development, and developmentpromotes health. • Education promotes health. The strong associationbetween health and level of education is particularlymarked with regard to women’s education. • Social factors have a profound influence onhealth. Culture, behaviour, social organization, allocation of family resources, healthcare seekingbehaviour, etc. dr.suzan yousif

6. Health and human behaviour • Human behaviour is an important dimension ofsocial medicine. The link between health andhuman behaviour is a major area of interest inpublic health with medical anthropologists andsociologists providing specificprofessional expertise. • The link between lifestyle and health is gainingmore attention as chronic diseasesincreasinglydominate the epidemiological pattern. The riskfactors associated with cancers, cardiovasculardiseases, diabetes and other chronic diseases relateto such lifestyle choices as the use of tobacco andalcohol, diet, nutrition and exercise. The pandemicof HIV/AIDS has highlighted the health importanceof sexual behaviour, making sexliterally amatter of life and death: life in its reproductivefunction and death in its association with the riskof acquiring deadly diseases. Access to and utilization ofhealth services Behavioural scientists are also interested in healthcareseeking behaviour of individuals and familiesranging from the self-treatment at home, to consultationswith traditional medicalpractitioners.Social medicine emphasizes therelationship between social factors and health status.It draws attention to the need for a multidisciplinaryapproach to health with deep involvementof social and behavioural scientists, economists,ethicists and political scientists. dr.suzan yousif

7. COMMUNITY HEALTH Community health deals with the services that aimat protecting the health of the community. Theinterventions vary from environmental sanitationincluding vector control to personal health care,immunization, health education andsuch like. Itincludes an important diagnostic element – ‘communitydiagnosis’ – aimed at surveying and monitoringcommunity health needs and assessing theimpact of interventions. COMMUNITY MEDICINE This usually refers to services that are provided atthe community level and is now often encompassedin the new term primary care. Communityphysicians, nurses and other health-care personnelare involved in providing careat clinics, healthcentres and in people’s homes. MODERN PUBLIC HEALTH The modern concept of public health includes allthese elements – preventive medicine, social medicine, community medicine, community health.Important features of modern public health includethe followingcharacteristic features. It is: ■ multidisciplinary; ■ multisectoral; ■ evidence-based; ■ equity-oriented. dr.suzanyousif

8. MULTIDISCIPLINARY Although medical practitioners constitute a vitalsegment of the public health practitioners, the contributionsfrom other health-related disciplinesare absolutely essential for achieving the goals ofpublic health. Thus, the public health team wouldinclude, as required, doctors, nurses, midwives,dentists and pharmacists; anthropologists, economistsand other social scientists; philosophers,ethicists and other experts on moral sciences, aswell as educationists, communications experts andmanagers MULTISECTORAL The health sector has two distinct roles. It is primarilyresponsible for planning and deliveringhealth services. It also has an important leadershipfunction in mobilizing intersectoral action.It should work with other ministries: with publicworks on water and sanitation; with education onthe health of school children and healthpromotion;with transport on the control of road trafficaccidents; and with agriculture on food security,nutrition, use of pesticides and the control ofzoonotic infections. EVIDENCE-BASED Modern public health demands that decisionsshould be science-based and knowledge-based.As far as possible, policy-making should be madeonly after objective analysis of relevant information.Where information is lacking, there is a clearindication for gathering data and carrying outresearch to inform decision-making. It is often statedthat researchers should present their results ina way that decision-makers can apply their findings.By the same token, policy-makers have theresponsibility to ensure that their decisions arebased onthe best available scientific evidence.Both researchers and policy-makers with theircommon interest in promoting the health of thepopulation need to work closely together in generatingand using sound evidence as the basis ofdecision-making. dr.suzan yousif

9. EQUITY-ORIENTED Public health programmes must be designed to promoteequity as the ultimate goal of all health action.The aim is to ensure for each member of society thehighest possible level of health. Public health programmesshould actively monitor equity and makenecessary corrections. Public health practitionersmust adopt a strongadvocacy role in persuadingdecision-makers and influential members of societythat, in the long run, equity in health is to everyone’sadvantage as a means of securing sustainabledevelopment and strengthening the socialcontractamong citizens from a wide variety of backgroundsand between them and their governments. It shouldbe made clear that solidarity with the poor is notmerely an act of charity but a mechanism for promotingthe welfare of all peoples. KEY PUBLIC HEALTH FUNCTIONS Public health services perform a wide range of functions, which can be classified as four keyelements: ■ assessing and monitoring of the health of thepopulation; ■ planning, implementing and evaluating publichealth programmes; ■ identifying and dealing with environmentalhazards; ■ communicating with people and organizationsto promote public health dr.suzan yousif

10. THE TROPICAL ENVIRONMENT The total environment of human beings includes allthe living andnon-living elements in their surroundings.It consists of three major components: physical,biological and social. The relationships of humanbeings to their environment is reciprocal in that theenvironment has a profound influence on them andthey in turn makeextensive alterations to the environmentto meet their needs and desires. PHYSICAL ENVIRONMENT This refers to the non-living part of the environment– air, soil, water, minerals – and climatic factorssuch as temperature and humidity. The physicalenvironment is extremely variable in the tropicscovering deserts, savannahs, upland jungle, colddry or humid plateaux, marshlands, high mountainsteppes or tropical rainforest.Climatic factors such as temperature and humidityhave a direct effect on humans, their comfortand their physical performance. The physical environmentalso exerts an indirect effect by determiningthe distribution of organisms in the biologicalenvironment: plants and animals which providefood, clothing and shelter; animals which competewith humans for food; and parasites and theirvectors which produce and transmit disease.Humans alter the natural characteristics of thephysical environment sometimes on a small scalebut often on a very large scale: from clearing asmall patch of bush, building a hut and digginga small canal to irrigate a vegetable garden to thebuilding of large cities, draining of swamps, irrigatingarid zones, damming rivers and creatinglarge artificial lakes. Many such changes haveproved beneficial but some aspects of thesechanges have created new hazards. dr.suzan yousif

11. BIOLOGICAL ENVIRONMENT All the living things in an area – plants, animalsand micro-organisms – constitute the biologicalenvironment. They are dependent on each otherand ultimately, on their physical environment.Thus, nitrogen-fixingorganisms convert atmosphericnitrogen into the nitrates that are essentialfor plant life. Plants trap energy from the sun byphotosynthesis. A mammal may obtain its nourishmentby feeding on plants (herbivore) or on otheranimals (carnivore) or both (omnivore). Undernatural conditions, there is a balanced relationshipbetween the growth and the size of the populationof a particular species, on the one hand, and itssources of food and prevalence of competitors andpredators, on the other hand.Humans deliberately manipulate the biologicalenvironment by cultivating useful plants to providefood, clothing and shelter, and raising farmanimals for their meat, milk, leather, wool andother useful products. They hunt and kill wildanimals, and destroy insects which transmit diseaseor which compete with them for food.In many parts of the tropics, insects, snails andother vectors of disease abound and thrive. This ispartly because the natural environment favourstheir survival but also because, in some of theseareas, relatively little has been done to controlthese agents. SOCIAL ENVIRONMENT This is the part of the environment that is entirelymade by humans. In essence, it represents the situationof human beings as members of society: familygroups, village or urbancommunities, cultureincluding beliefs and attitudes, the organization ofsociety – politics and government, laws and thejudicial system, the educational system, transportand communication, and social services includinghealth care. dr.suzan yousif

12. HEALTH AND DEVELOPMENT The close link between health and development inother sectors is clearly recognizable. There is a clearcorrelation between economic, industrial and otherindices of development and the health status ofpopulations and communities. At one end of thespectrum are the industrialized, affluent developedcountries and at the other end are the least developedcountries that still rely largely on traditionalagricultural practices and simple crafts. The term‘developing countries’ is used to describe countriesthat have not as yet achieved a high level of industrialand economic development. Characteristicfeatures of developing countries include relatively low income, low literacy rates, low access to electricityand other modern sources of energy, andhigh mortality rates among vulnerable groups(children, pregnant women). These factors interact:illiteracy is associated with poverty; poverty predisposesto ill health; and ill health aggravatespoverty. dr.suzan yousif

13. There is much variation in the extent of technicaldevelopment in the various countries in the tropics.Some of these countries are now highly developedwhilst others are still in the early stages. Some ofthe developing countries show certain commonfeatures: limited central organization of services,scattered populations living in small self-containedunits, low level of economic development, limitededucational facilities, and inadequate control of commonagents of disease. Some of these communitiesare still held tightly in the vicious circle of ignorance,poverty and disease. Rapid economic development and the growth ofmodern industries are causing mass migrationsfrom rural to urban areas. Faster means of transportation,progress in education, the control anderadication of major endemic diseases, and otherdevelopments are effectively breaking the chainsof disease, poverty and ignorance. At the sametime new problems are emerging, including thoseresulting from the social and psychological stressesimposed by these bewildering changes and theirdestructive effects on traditional family life andcommunal relationships.In these transitional societies therehave beenmarked changes in the patterns of disease. Noncommunicablediseases and conditions are now replacing communicable diseases which were formerlythe predominant causes of disability, diseaseand death. Malnutrition in the form of the deficiencyof specific nutrients is being succeeded by problemsresulting from over-indulgence, thus obesity isreplacing marasmus as the predominant nutritionalproblem. Alcoholism anddrug abuse are emergingas manifestations of social stresses and tensions dr.suzan yousif

14. TTHE ECOLOGICAL APPROACHTO PUBLIC HEALTHO PUBLIC HEALTH In public health, it is useful to consider the reciprocalrelationship between humans and their totalenvironment. In the search for the causes of disease,it is not sufficient merely to identify the specificagent of a disease, such as a virus or a parasite,but it is desirable to identify the influence of environmentalfactors on the interaction betweenhumans and the specific agent. For example, thetyphoid bacillus (Salmonella typhi) is known to bethecausative agent of disease but the occurrenceof outbreaks of typhoid is determined by variousenvironmental factors: water supply, methods ofsewage disposal, prevalence of typhoid carriers,personal habits of the people (cleanliness), use ofraw water, attitude to and use of medical services,including vaccination. Similarly, a specific nutritionaldeficiency, such as ariboflavinosis, shouldnot be viewed merely as a discrete metabolic defectbut it should be seen in the context of the foodhabits of the community including food taboos, thelevel of education and income of the populationand the local agriculture.From this ecological approach, one can derive arational basis for the control of disease within thepopulation. Typhoid control should go beyond thetreatment of the individual patient, to includeimmunization of susceptible groups, protectionof water supplies, safe disposal of waste andimprovement of personal hygiene. Malnutrition ismanaged not only by giving pills containing concentratednutrients but also by giving suitableadvice about diet and promoting the cultivation ofnutritionalfoods both commercially by farmersand privately in home gardens; in more complexsituations management may extend to promotionof welfare services such as unemployment benefitsand food supplements for the needy. dr.suzanyousif

15. The healthworker should seek suitable opportunities forimproving the health of the people through actionon theenvironment. It is important that theselessons should be repeatedly emphasized.The individual and the family can do much aboutthe cleanliness of the home and its immediatesurroundings, thereby reducing the occurrence of anumber of infectious diseases. Domestic accidents,especially in such high-risk areas as the kitchenand thebathroom, can be prevented by carefulattention to the environment in the home. Theindividual needs to recognize how the environmentin the home affects the health of the family,why each person must act to improve the situationand what the individual and the family can do todeal with the problem.The community should be approached as awhole to deal with the widespread problems thataffect many families, and also for help with thoseproblems which require action beyond the meansof individual families. For example, certain environmentalsituations may require organization atthe community level and must be designed in thecontext of the culture of the local community: ■ collection and storage of water to ensure thateach family has an adequate supply of safewater; ■ disposal of human and other wastes; ■ control of other environmental hazards. In most developing countries, modern developmentprojects and urbanization are introducingnew risks . It is therefore necessary toensure that these new initiatives should be carefullyexamined at the community level with regardto their appropriate siting and safe management,with minimal risk to the environment.At the national and international level, large-scaleprojects such as the creation of artificial lakes, irrigationprojects and mining of minerals includingoil, require careful assessment of their environmentalimpact. The adverse effects can best beminimized by careful planning so that as far aspossible protective measures can be incorporated into the design of these projects. dr.suzanyousif

16. Some developed countries facing problems ofdisposing of toxic chemicals and radioactive wastehave resorted to dumping them in developingcountries. The serious concerns raised by these events should lead to tighter international controls. Developing countries are also involved in dealingwith environmental issues which are of globaldimensions: the denudation of the tropical forestand its probable adverse effects on climate; theuse of chlorofluorocarbons (CFCs) that destroy theozone layer; and the extensive use of fossil fueland consequent increase in greenhouse gasesidentified as the main cause of global warming. dr.suzan yousif