PHHE 295. Chapter 4. Epidemiology: Prevention and Control of Diseases and Health Conditions

PHHE 295

Chapter 4: Epidemiology: Prevention and Control of Diseases and Health Conditions

Chapter Objectives:

1)      Explain the differences between communicable (infectious) and non-communicable (noninfectious) diseases and between acute and chronic diseases and provide examples of each.

2)      Describe and explain communicable and multi-causation disease models.

3)      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.

4)      Explain why non-communicable diseases are a community health concern and provide some examples of important non-communicable diseases.

5)      Explain the difference between primary, secondary, and tertiary prevention of disease and provide examples of each.

6)      List and explain the various criteria that communities might use to prioritize their health problems in preparation for the allocation of prevention and control resources.

7)      List and discuss important measures for preventing and controlling the spread of communicable diseases in a community.

8)      List and discuss approaches to non-communicalbe disease control in the community.

9)      Define and explain the purpose and importance of health screenings.

10)  Outline a chronic, non-communicable disease control program and includes primary, secondary, and tertiary prevention components.

Key Terms

·         Communicable (Infectious) Disease:  An illness caused by some specific biological agent or its toxic products that can be transmitted from an infected person, animal or inanimate reservoir to a susceptible host.

·         Non-Communicable (Noninfectious) Disease: A disease that cannot be transmitted from infected host to susceptible host.

·         Infectivity: The ability of a biological agent to enter and grow in the host.

·         Pathogenicity: The capability of a communicable disease agent to cause disease in a susceptible host.

·         Communicable Disease Model: A visual representation of the interrelationships among causative agent, host, and environment.

·         Agent: The cause of the disease or health problem.

·         Host: A person or other living organism that affords subsistence or lodgment to a communicable agent under natural conditions.

·         Chain of Infection: A model to conceptualize the transmission of a communicable disease from its source to a susceptible host.

·         Case: A person who is sick with a disease.

·         Carrier: A person or animal that harbors a specific communicable agent in the absence of discernible clinical disease and serves as a potential source of infection to others.

·         Zoonosis: A communicable disease transmissible under natural conditions from vertebrate animals to humans.

·         Anthroponosis: A disease that infects only humans.

·         Direct Transmission: The immediate transfer of an infectious agent by direct contact between infected and susceptible individuals.

·         Indirect Transmission: Communicable disease transmission involving an intermediate step.

·         Vehicle: An inanimate material or object that can serve as a source of infection.

·         Vector: A living organism that can transmit a communicable agent to susceptible host.

·         Etiology: The cause of a disease.

·         Multi-Causation Disease Model: A visual representation of the host together with carious internal and external factors that promote and protect against disease.

·         Coronary Heart Disease: A chronic disease characterized by damage to the coronary arteries in the heart.

·         Cerebrovascular Disease (Stroke): A chronic disease characterized by damage to blood vessels of the brain resulting in a disruption of circulation to the brain.

·         Malignant Neoplasm: Uncontrolled new tissue growth resulting from cells that have lost control over their growth and division.

·         Metastasis: The spread of cancer cells to distant parts of the body by the circulatory or lymphatic system.

·         Prevention: The planning for and taking of action to forestall the onset of a disease or other health problem.

·         Intervention: Efforts to control a disease in progress.

·         Eradication: The complete elimination or uprooting of a disease.

·         Primary Prevention: Preventative measures that forestall the onset of illness or injury during the pre-pathogenesis period.

·         Secondary Prevention: Preventative measures that lead to an early diagnosis and prompt treatment of a disease or injury to limit disability and prevent more severe pathogenesis.

·         Tertiary Prevention: Measures aimed at rehabilitation following significant pathogenesis.

·         Isolation: The separation of infected persons from those who are susceptible.

·         Quarantine: Limitation of freedom of movement of those who have been exposed to a disease and may be incubating it.

·         Disinfection: The killing of communicable disease agents outside the host, on countertops, for example.

·         Bloodborne Pathogens: Disease agents that are transmissible in blood and other body fluids.

·         Bloodborne Pathogens Standard: A set of regulations by OSHA that sets forth the responsibilities of employers and employees with regard to precautions to be taken concerning bloodborne pathogens in the workplace.

·         Unmodifiable Risk Factors: Factors contributing to the development of a non-communicable disease that cannot be altered by modifying one’s behavior or environment.

·         Modifiable Risk Factors: Factors contributing to the development of a non-communicable disease that can be altered by modifying one’s behavior or environment.

Chapter Summary

·         Diseases can be classified and communicable (infectious) or non-communicable (noninfectious), and acute or chronic.

·         Acute diseases last for less than 3 months, whereas chronic diseases continue longer than 3 months.

·         Communicable diseases are caused by biological agents and are transmissible from a source of infection to a susceptible host.

·         The process of communicable disease transmission is best understood by the chain of infection model, in which the interruption of disease transmission can be visualized as the breaking of one or more links in the chain.

·         Non-communicable diseases are often the result of multiple risk factors that can be genetic, behavioral, and environmental in nature.

·         Several of the non-communicable diseases rank among the leading causes of death in America.

·         There are three levels of disease prevention—primary, secondary, and tertiary.

·         Primary prevention includes measures that forestall the onset of disease or injury, while secondary prevention encompasses efforts aimed at early detection and intervention to limit disease and disability. Tertiary prevention includes measures aimed at re-education and rehabilitation after significant pathogenesis has occurred.

·         Both the spread of communicable diseases and the prevalence of non-communicable diseases can best be reduced by the appropriate application of primary, secondary, and tertiary preventative measures by the community and the individual.

·         The prevention and control of non-communicable diseases require both individual and community efforts.