Instructor: Ping Luo, Ed.D Fall Semester, 2004
Chapter Objectives • Explain the difference between communicable and noncommunicable diseases and between acute and chronic diseases. • Describe and explain communicable and multicausation disease models. • Explain why noncommunicable diseases are a community health concern and provide some examples of communicable and provide some examples of important noncommunicable diseases
Chapter Objectives • Explain how communicable diseases are transmitted in a community using the “chain of infection” model and use a specific communicable disease to illustrate your explanation. • Explain the difference between primary, secondary, and tertiary prevention of disease.
Chapter Objectives • List and explain the various criteria that communities might use in order to prioritize their health problems in preparation for the allocation of prevention and control resources • List and discuss the measures for preventing and controlling the spread of communicable diseases in a community.
Chapter Objectives • List and discuss approaches to non-communicable disease control in a community. • Define and explain the purpose and importance of health screenings. • Outline a chronic, noncommunicable disease control program that includes primary, secondary, and tertiary disease prevention components.
Classification of Diseases & Health Problems • 4 Classification Schemes • Organ or Organ System • i.e., heart disease, kidney disease, respiratory infection • Causative Agent • Biological Agents • Chemical Agents • Physical Agents
Causative Agents for Diseases & Injuries Biological Agents Chemical Agents Physical Agents Viruses Rickettsiae Bacteria Fungi Protozoa Metazoa Pesticides Food additives Pharmacologics Industrial chemicals Air pollutants Cigarette smoke Heat Light Radiation Noise Vibration Speeding objects
Classification of Diseases & Health Problems Organ or Organ System • i.e., heart disease, kidney disease, respiratory infection Causative Agent • Biological Agents • Chemical Agents • Physical Agents Communicable vs Non communicable Acute vs Chronic • Peak symptoms within 3 months (acute) or longer than 3 months (chronic)
Types of Diseases Examples Acute Diseases Communicable Noncommunicable Chronic Diseases Communicable Noncommunicable Common cold, pneumonia, mumps, measles, pertussis, typhoid fever, cholera Appendicitis, poisoning, trauma Tuberculosis, AIDS, Lyme disease, syphilis, rheumatic fever Diabetes, coronary heart disease, osteoarthritis, cirrhosis of the liver
Communicable Disease Model Triangle Epidemiologic Model
Communicable Disease Model Agent - the element that must be present in order for the diseases to occur.
Communicable Disease Model Host - any susceptible organism invaded by an infectious agent Agent
Communicable Disease Model Host Agent Environment - all other factors that inhibit or promote disease transmission.
Chain of Infection A model to conceptualize the transmission of a communicable disease from its source to a susceptible hose
Chain of Infection Pathogen •is the disease causing agent
Chain of Infection Pathogen Reservoir •is the habitat in which an infectious agent normally lives & grows • Human: symptomatic or asymptomatic • Animal: called zoonoses • Environmental: plants, soil, and water
Chain of Infection Portal of exit Pathogen Reservoir - is the path by which an agent leaves the source host
Chain of Infection •how pathogens are passed Portal of exit Pathogen Trans- mission Reservoir Modes of Transmission Direct - Direct contact - Droplet spread Indirect - Airborne - Vehicleborne - Vectorborne
Chain of Infection Portal of exit Pathogen Portal of entry Trans- mission Reservoir • agent enters susceptible host Respiratory Oral Skin Intravenous Gastrointestinal
Chain of Infection Portal of exit Pathogen Portal of entry New Host Trans- mission Reservoir • Final link is a susceptible host
Noncommunicable Disease Model Your genetic endowment
Noncommunicable Disease Model Personality Beliefs Your genetic endowment Behavioral choices
Noncommunicable Disease Model Environment Health Care System Personality Beliefs Economics Your genetic endowment Water Quality Behavioral choices Air Pollution
Prioritizing Prevention & Control Efforts • Leading Causes of Death • Years of Potential Life Lost • Economic Cost to Society
Prioritizing Prevention and Control Efforts • Leading Causes of Death • Years of Potential Life Lost • Economic Cost to Society
Prevention, Intervention, Control, and Eradication of Diseases • Prevention • primary • secondary • tertiary • Intervention • which is defined as taking of action during an event • Control • general term used in the containment of disease • Eradication • total elimination of the disease
Levels of Prevention • Tertiary Prevention • is to retrain, reeducate, and rehabilitate the patient who has already incurred disability • Primary Prevention • is the forestalling of the onset of illness or injury during the pre-pathogenesis period (before the diseaseprocess begins) • Secondary Prevention • is the early diagnosis and prompt treatment of diseases before the disease becomes advanced anddisability becomes severe
Chapter 4 Epidemiology: Prevention and Control of Diseases and Health Conditions