Concepts of prevention and control of diseases

Concepts of prevention and control of diseases including levels of prevention. Briefly on concepts of prevention and control of oral diseases

1. CONCEPTS OF PREVENTION AND CONTROL OF DISEASES R. Venkitachalam Seminar No: 5

2. CONTENTS Concepts of prevention of disease Definition Timeline of approaches to prevention Levels of prevention Levels of prevention for dental diseases Concepts of control of disease Disease control Disease elimination and eradication Monitoring Surveillance Conclusion References

3. CONCEPTS OF PREVENTION

4. D isease prevention: Definition Activities designed to protect patients and other members of the public from actual or potential health threats and their harmful consequences - Mosby’s Medical Dictionary, 8 th edition.2009 Disease prevention covers measures not only to prevent the occurrence of disease, such as risk factor reduction, but also to arrest its progress and reduce its consequences once established. Reference: adapted from Glossary of Terms used in Health for All series. WHO, Geneva, 1984

5. Successful prevention depends upon: Knowledge of causation Dynamics of transmission Identification of risk factors and risk groups Availability of prophylactic or early detection and treatment measures Facilities for these treatment procedures Evaluation and development of these procedures

6. Levels of prevention The concepts of prevention can be best defined in the context of “levels of prevention”. But how many levels of prevention??

7. Timeline

8. 1953 – Leavell and Clark Book: Textbook of preventive medicine 5 levels of application Health promotion Specific protection Early recognition and prompt treatment Disability limitation Rehabilitation Based on his paper on the disease syphilis

9. 1957 – Commisssion on chronic illness Prevention of chronic illness : Volume 1 First use of the words primary and secondary prevention Primary prevention: averting the occurrence of disease Secondary prevention : halting the progression of disease from its early unrecognized stage to a more severe one and preventing complications

10. 1958 – Leavell and Clark Second edition retitled: Preventive Medicine for the Doctor and the Community Defined five levels into three categories Primary prevention Health promotion (serving to further general health and well-being) Specific protection ( measures applicable to a particular disease or group of diseases in order to intercept the causes before they involve man )

11. Secondary prevention early recognition and prompt treatment (preventing spread to others if the disease is communicable, complications or sequelae , and prolonged disability ). Tertiary prevention disability limitation (prevention or delaying of the consequences of clinically advanced disease ) rehabilitation (aiming at prevention of complete disability after anatomic and physiologic changes are stabilized).

12. 1965 – Leavell and Clark Third edition: Preventive Medicine for the Doctor and the Community Referred levels of prevention as “phases of prevention” and Disability limitation was transferred to secondary phase of prevention

13. 1983 - Gordon Public Health Reports Limited the use of word prevention to persons who have not yet suffered and discomfort or disability due to the disease Classification – target population Universal measures : for everyone Selective measures : for above-risk demographies Indicated measures : for individuals at risk

14. 1985 - Tannahill Reviewed the usages of primary, secondary and tertiary by different authors, and proposed a new classification Foci of prevention Prevention of the first occurrence of an illness or unwanted phenomenon P revention of avoidable consequences of illness or other unwanted state through early detection when this favorably affects the outcome P revention of avoidable complications of established disease or other unwanted state Prevention of recurrence.

15. 2001 – Froom and Benbassat Expanded categories of prevention from three to seven Level 1: reducing exposure to an etiologic agent Level 2: increasing resistance to the disease Level 3: defining it as screening for risk factors for disease (in asymptomatic individuals) in order to reduce them. Level 4: prevention of recurrence (in asymptomatic individuals after a disease-related event) Level 5: treatment aimed at prevention of complications (in asymptomatic individuals after a disease-related event) Level 6: treatment of symptomatic patients for cure, palliation, or reduction of mortality Level 7: rehabilitation for “adjustment to irremediable conditions.

16. 2008 – 2009: Ronald Hattis (draft stage as on 2012) Classification according to stages of disease Stag e s of Dis e ase D e v e l op m e nt Co r re spondi n g Stag e s of P re v e ntion 1 E x posure Avoid a n c e of E x posure 2 A c quisition R e du c tion of A c quisition 3 Adv a n ce m e nt/Pro g r e ssion I nt e r r uption of Pr o g r e ssion 4 Complic a tions Avoid a n c e of Complic a t i ons 5 D e a th or Disa b ili t y D e l a y of Mo r t ali t y Rehabilitation of Disabili t y Palliative Care for I n evitable D e ath

17. Sta g e s Dise a se I Dise a se II Disease III     T y pe 2 Di a b e tes H I V Dental caries 1 E x posure Avoid a n ce : H e a lt h y ea ti n g , limit simple c a rbo h y d ra t e s, maintain h ea lt h y w eg ht , e x e r c ise Abstin e n c e f r om s e x (or sc r ee ni n g a nd monoga m y o f s e rone g a tive p a rtn e rs ) , no inj ec tion d r ug u s e Avoidance of sticky fermentable carbohydrate diet 2 Dise a se A c quisition R e du c tion: W e i g ht loss, consider m e tfo r min if insulin r e sistan c e /p r e- dia b e tes Condom promotion a nd p r o g r a ms to discou r a g e d r u g a buse, n ee d l e sha r ing Sealing of pit and fissure, use of fluorides and plaque control 3 I nt e r r uption or De l a y of Dise a se Adv a n ce m e nt: Anti - diab e tic dr u g s, monitor h g b A- 1C, FB S, p r otein u ri a , lipids; b a ri a tric su r g e r y if indi ca ted Antibo d y s c r e e ni n g , monitoring C D 4, vir a l lo a d; tr e a tm e nt with a ntir e trovir a ls Preventive resin restorations, conservative restorations, ART 4 Avoid a n c e or De l a y of Dise a se Complic a tion s : ACE I nhibitor/ARB to p re v e nt r e n a l sequ e l ae , strict g lucose c ontrol ( insulin if n e ce ssa r y ) , lipid cont r ol, foot a n d e y e c a re Prop h y l a c tic tr e a tm e nt for oppo r tunistic inf e c tions Indirect pulp capping, deep caries restorations 5 D e l a y of Mort a li t y f rom Dise a s e complications R e n a l Dia l y si s , c o r on a r y stent o r b y p a ss I ntensi v e tr e a tm e nt for severe oppo r tunistic infections Root canal treatment and prosthetic rehabilitation

18. Beyond disease prevention . . . Breslow proposed in 1999 moving “beyond disease prevention and aiming for “the energy and reserves of health that permit a buoyant life, full of zest the eager ability to meet life’s challenges.” Thus a supplementary paradigm consisting of four stages of health promotion/wellness was developed . .

19. Stages of wellness Stage 1: Exposure to positive health influences. Stage 2: Adoption of positive health practices (such as healthy diet, exercise, recreation, adequate sleep, etc.). Stage 3: Increase in indicators of health and wellness due to the healthy practices (such as increased strength and flexibility, immunity, optimal BMI, etc.). Stage 4: Achievement of specific defined health and wellness goals, both subjective (e.g., sense of wellbeing and energy, fulfilling social relationships) objective measures (e.g., high cognitive function, productivity, capacity for role fulfillment or achievement)

20. LEVELS OF PREVENTION

21. LEVELS OF PREVENTION The concept of prevention is best defined in terms of levels of prevention. Traditionally, Primordial prevention Primary prevention Secondary prevention Tertiary prevention Quaternary prevention

22. PRIMORDIAL PREVENTION Prevention of emergence or development of risk factors in countries or population groups in which they have not yet appeared. it consists of actions and measures that inhibit the emergence and establishment of environmental, economic, social and behavioral conditions, cultural patterns of living known to increase the risk of disease . - John Last’s dictionary

23. Primordial prevention . . . Mainly associated with chronic diseases Intervention – Individual and mass education Has to start in childhood when health risk behaviour begins

24. Primordial prevention . . . Examples of primordial prevention National programmes and policies on: Food and nutrition Against smoking and drugs To promote regular physical activity

25. Primordial prevention . . . Responsibility of primordial prevention: parents , teachers and peer groups: imparting health education Government: legislating and enacting laws Professional and nonprofessional organisations Industry Hospitals, health practitioners, health care workers

26. PRIMARY PREVENTION Action taken prior to the onset of disease, which removes the possibility that a disease will ever occur Intervention – prepathogenesis stage of disease Concept of positive health: an acceptable level of health that will enable every individual to lead a socially and economically productive life

27. p rimary prevention . . . Approaches for primary prevention for chronic diseases (WHO): Population (mass) strategy: Directed at whole population irrespective of individual risk levels Directed towards socio-economic, behavioral and lifestyle changes High risk strategy: To individuals at special risk

28. Population approach Recognises influence of society Risk reduction can be achieved at population level Effective in dose-response relationship of diseases Less effective in situations where there is no dose-response relationship ADVANTAGES DISADVANTAGES

29. High risk approach Cost effective Motivation level is higher Easier for health professionals to promote change Individuals would have been aware and exposed to the risk Fails to address public health problems which arise from small risks Tends to medicalise prevention Does not focus on what influences behaviour Little overall impact on control of disease ADVANTAGES DISADVANTAGES

30. POPULATION AND HIGH RISK STRATEGIES

31. Achievements of primary prevention: Controlling diseases like cholera, typhoid, dysentry , plague, tuberculosis, by raising standard of living Holistic approach Modes of intervention: Health promotion Specific protection p rimary prevention . . .

32. Health promotion Process of enabling people to increase control over and to improve health Not directed against any particular disease Interventions in this area: Health education Environmental modifications Nutritional interventions Lifestyle and behavioural changes

33. Values in health promotion Equity and social justice A holistic definition of health Covers a full range of health determinants Recognizes influence of environment on health Seeks to enhance people’s social participation Involves intersectoral collaboration ( ottawa reference)

34. Specific protection Efforts directed toward protection against specific diseases Interventions Immunization Use of specific nutrients Chemoprophylaxis Protection against occupational hazards Protection against accidents Protection from carcinogens Avoidance of allergens etc.

35. SECONDARY PREVENTION Action which halts the progress of the disease at its incipient stage and prevents complications Intervention – early pathogenesis stage It is the domain of clinical medicine Drawback Patient already subjected to mental anguish & physical pain More expensive than primary prevention

36. Modes of intervention: Early diagnosis (screening tests, case finding programs) Adequate/prompt treatment Effects: Seeks out unrecognized disease Provides treatment before irreversible changes occur Reverses communicability of infectious diseases Protects community secondary prevention . . .

37. Early diagnosis and prompt treatment Earlier diagnosed – better prognosis Reduces morbidity and mortality Effective in acute conditions

38. TERTIARY PREVENTION All measures available to reduce or limit impairments and disabilities, minimize suffering caused by existing departures from good health and to promote the patients adjustment to irremediable conditions Intervention – late pathogenesis stage Modes of intervention: Disability limitation Rehabilitation

39. Disability limitation To prevent or halt the transition of disease process from impairment to handicap Disease  impairment disability handicap Impairment: any loss or abnormality of psychological, physiological or anatomic structure or function Disability: any restriction or lack of ability to perform an activity in the manner considered normal for a human being Handicap: disadvantage for a given individual, resulting from impairment or disability, that limits or prevents the fulfillment of a role that is normal for that individual

40. ACCIDENT Impairment: Loss of an anatomical structure Disability: Lack of ability to perform an activity Handicap: Prevents fulfillment of normal role

41. Disease - dental caries Impairment – loss of tooth Disability – cant talk Handicap – cant socialize

42. Rehabilitation The combined and coordinated use of medical, educational, social and vocational measures for training and retraining the individual to the highest possible level of functional ability Types of rehabilitation Medical: restoration of function Vocational: restoration of capacity to earn a livelihood Social: restoration of family and social relationships Psychological: restoration of personal dignity and confidence

43. Examples of rehabilitation Establishing schools for blind Provision of aids for crippled Exercises in neurological disorders Prosthetic restoration of lost tooth Requires cooperation from different sections of society

44. Principles of tertiary prevention TERTIARY PREVENTION Enable timely recovery Re-stabilize Re-train Re-motivate Re-socialize Re-integrate

45. QUATERNARY PREVENTION The action taken to identify patient at risk of over- medicalisation , to protect him from new medical invasion , and to suggest to him interventions, which are ethically acceptable. Quaternary prevention is the set of health activities to mitigate or avoid the consequences of unnecessary or excessive intervention of the health system. Quaternary prevention should take precedence over any alternative preventive, diagnostic and therapeutic, as is the practice version ‘ primum non nocere ’

46. Intervention types: Healthcare professionals must be aware of the consequences of their decisions, and include quaternary prevention interventions in their daily clinical practice with each patient Do not mistake risk factor with disease. To avoid check ups or unnecessary exams. To avoid technical interventionism in healthcare. To avoid the indiscriminate use of antibiotics (very often unnecessary, with the subsequent unjustified increase of bacterial resistances)

47. EXAMPLES OF LEVELS OF PREVENTION OF COMMON ORAL DISEASES

48. EXAMPLES OF PREVENTIVE STRATEGIES FOR DENTAL CARIES Levels of prevention PRIMARY SECONDARY TERTIARY Modes of intervention Health promotion Specific protection Early diagnosis and prompt treatment Disability limitation Rehabilitation Services provided by individual Diet planning, demand for dental care Use of fluoride/fluoridated water, fluoride dentifrice, oral hygiene practices Self-examination and referral; use of dental services Use of dental services Use of dental services Services provided by community Dental health education, promotion of research Community or school water fluoridation, school fluoride mouthrinse /tablet/sealant program, Periodic screening and referral; provision of dental services Provision of dental services Provision of dental services Services provided by the dental professional Patient education, plaque control program, diet counselling , recall reinforcement, caries activity tests Topical application of fluoride, fluoride supplements; pit and fissure sealants Complete examination, prompt treatment of incipient lesions, PRR, simple restorations, pulp capping Complex restorations, pulpotomy , RCT, extractions Removable and fixed prosthodontics, minor tooth movements, implants

49. EXAMPLES OF PREVENTIVE STRATEGIES FOR PERIODONTAL DISEASE Levels of prevention PRIMARY SECONDARY TERTIARY Modes of intervention Health promotion Specific protection Early diagnosis and prompt treatment Disability limitation Rehabilitation Services provided by individual Periodic visits to dental office; demand for preventive services Oral hygiene practices Self-examination and referral; use of dental services Use of dental services Use of dental services Services provided by community Dental health education, promotion of research; provision of oral hygiene aids Supervised school tooth-brushing programs Periodic screening and referral; provision of dental services Provision of dental services Provision of dental services Services provided by the dental professional Patient education, plaque control program, recall reinforcement Correction of tooth malalignment , prophylaxis Complete examination, scaling and curettage, corrective restorative and occlusal services Deep curettage, root planing , splinting, periodontal surgery, selective extractions Removable and fixed prosthodontics, minor tooth movements

50. EXAMPLES OF PREVENTIVE STRATEGIES FOR ORAL CANCER Levels of prevention PRIMARY SECONDARY TERTIARY Modes of intervention Health promotion Specific protection Early diagnosis and prompt treatment Disability limitation Rehabilitation Services provided by individual Periodic visits to dental office; demand for preventive services Avoidance of known irritants Self-examination and referral; use of dental services Use of dental services Use of dental services Services provided by community Dental health education, promotion of research Periodic screening and referral; provision of dental services Provision of dental services Provision of dental services Services provided by the dental professional Patient education Removal of known irritants in oral cavity Complete examination, biopsy, oral cytology, complete excision Chemotherapy, radiation therapy, surgery Maxillofacial and removable prosthodontics, plastic surgery, speech therapy and counselling

51. Understanding prevention through disease pathogenesis

52. Eg : understanding dental caries Tooth + Bacteria = Acid Demineralization Sensitivity and white spots Pits and cavitation Deep cavities, pulp invl . Sensitivity, food lodgement pain Loss of teeth, difficulty in chewing, esthetics,

53. Eg: understanding dental caries

54. CONCEPTS OF DISEASE CONTROL

55. DISEASE CONTROL Describes (ongoing) operations aimed at reducing: The incidence of disease Duration of disease (risk of transmission) Effects of infection (both physical and psychosocial) Financial burden to the community Mainly focused on primary and secondary prevention

56. Public health approach to disease control

57. Disease control includes . . . public policy intervention that restricts the circulation of an infectious agent beyond the level that would result from spontaneous, individual behaviors to protect against infection Reduction to zero of the incidence of a specified disease in a defined geographical area as a result of deliberate efforts Termination of all transmission of infections by extermination of infectious agents The specific infectious agent no longer exists in nature or in the laboratory

58. Disease eradication All or none law Only one disease has been eradicated so far: Small pox Eradication underway for: Poliomyelitis Dracunculiasis Yaws Malaria Measels

59. Framework for eradication

60. Monitoring Monitoring: it is the performance and analysis of routine measurements aimed at detecting changes in the environment or health status of a population Eg : monitoring of air pollution, water quality, growth and nutritional status Also refers to performance of health service or health professional or the extent of patient’s compliance

61. Surveillance Surveillance: continuous scrutiny of the factors that determine the occurrence and distribution of disease and other conditions of ill-health Objectives of surveillance: To provide information about new and changing trends in health status of a population To provide feed back which may be expected to modify policy and system Provide timely warning of public health disasters so that interventions can be mobilized

62. Surveillance is a continuous process which involves three primary activities: Collection of relevant data for a specified population , time period and/or geographic area ; Meaningful analysis of data ; Routine dissemination of data with accompanying interpretation. surveillance . . .

63. Duties of health care professionals in surveillance Identify and describe each individual having an infection as quickly as possible after exposure. Determine the source of infection. Identify exposed individuals to whom the infection may have been transmitted. Specify the frequency of occurrence of infection in population groups at risk by person, place and time . Identify populations that are experiencing, or might experience , an increased frequency of infection. Prepare and distribute surveillance reports to health care professionals participating in disease prevention and control activities.

64. Types of surveillance Passive surveillance: receipt of reports of infections/disease from physicians, laboratories and other health care professionals required to submit such reports as defined by public health legislation Active surveillance: Active disease surveillance is also based on public health legislation and refers to daily, weekly or monthly contacting of physicians, hospitals, laboratories , schools or others to “actively” search for cases Usually seasonal or done during disease outbreaks

65. CONCLUSION Understanding disease pathology is the first step towards formulating preventive measures Prevention can be achieved in any stage of disease Primordial or primary prevention is most effective and economical Disease control is also a part of prevention which is achieved by means of continuous monitoring and surveillance of disease

66. REFERENCES Miller M, Barrett S, Henderson DA. Control and Eradication. In: Jamison DT, Breman JG, Measham AR, Alleyne G, Claeson M, Evans DB, et al., editors. Disease Control Priorities in Developing Countries [Internet]. 2nd ed. Washington (DC): World Bank; 2006 [cited 2015 Feb 5]. Available from: http://www.ncbi.nlm.nih.gov/books/NBK11763 / DCP_1163-1176.qxd - ch62.pdf [Internet]. [cited 2015 Feb 9]. Available from: http:// www.ncbi.nlm.nih.gov/books/NBK11763/pdf/ch62.pdf Molyneux DH, Hopkins DR, Zagaria N. Disease eradication, elimination and control: the need for accurate and consistent usage. Trends Parasitol . 2004 Aug;20(8):347–51.

67. REFERENCES First draft about 2000 words; another 2000 may be added: - Stages of Prevention 1-12.pdf [Internet]. [cited 2015 Feb 5]. Available from: http:// www.capreventivemed.org/wp-content/themes/eventbrite-child/documents/Stages%20of%20Prevention%201-12.pdf Clark EG. Natural History of Syphilis and Levels of Prevention*. Br J Vener Dis. 1954 Dec;30(4):191–7. admin. Epidemiological basis for preventive strategies [Internet]. Health Knowledge. 2010 [cited 2015 Feb 9]. Available from: http://www.healthknowledge.org.uk/public-health-textbook/research-methods/1c-health-care-evaluation-health-care-assessment/epidemiological-basis-pstrategies

68. REFERENCES Dowdle WR. The principles of disease elimination and eradication. Bull World Health Organ. 1998;76( Suppl 2):22–5 . Have You Heard of “Primordial Prevention”? - Improving Population Health [Internet]. [cited 2015 Feb 9]. Available from: http:// www.improvingpopulationhealth.org/blog/2011/05/primordial_prevention.html The Five Stages of Prevention: A New Paradigm for Classifying the Prevention of Disease (Updated 2014) [Internet]. [cited 2015 Feb 5]. Available from: http://www.academia.edu/5673406/The_Five_Stages_of_Prevention_A_New_Paradigm_for_Classifying_the_Prevention_of_Disease_Updated_2014_

69. REFERENCES Soben Peter. Essentials of Public Health Dentistry. 5th ed. New Delhi: Arya Publising House; 2013. PARK K. PARK’S TEXTBOOK OF PREVENTIVE AND SOCIAL MEDICINE. 21st ed. Jabalpur: Banarsidas Bhanot ; 2011.