Chap 4: Epidemiology: Prevention and Control of Disease and Health Conditions Anita Sego Spring, 2005.

Chap 4: Epidemiology: Prevention and Control of Disease and Health Conditions

Anita Sego

Spring, 2005

Chap 4: Prevention and Control

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

VirusesRickettsiaeBacteriaFungiProtozoaMetazoa

PesticidesFood additivesPharmacologicsIndustrial chemicalsAir pollutantsCigarette smoke

HeatLightRadiationNoiseVibrationSpeeding 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)


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

Types of Diseases Examples


Communicable Disease Model

Epid

emio

logi

c Triangle

Model



Agent - - the element that must be present in order for the diseases to occur.



Agent

Host - any susceptible organism invaded by an infectious agent



Agent

Host

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

PathogenPathogen

- - is the disease causing agent


Chain of Infection

• is the habitat in which an infectious agent normally lives & grows

• Human: symptomatic or asymptomatic

• Animal: called zoonoses

• Environmental: plants, soil, and water

PathogenReservoirReservoir


Chain of Infection

• is the path by which an agent leaves the source host

PathogenReservoirPortalPortalof exitof exit


Chain of Infection

Modes of Transmission Direct - Direct contact - Droplet spread Indirect - Airborne - Vehicleborne - Vectorborne

Pathogen - how pathogens are passedReservoir

Portalof exit

Trans-Trans-missionmission


Chain of Infection

PathogenReservoirPortalof exit

Trans-mission

- agent enters susceptible host

PortalPortalof entryof entry

RespiratoryOralSkin

IntravenousGastrointestinal


Chain of Infection

PathogenReservoirPortalof exit

Trans-mission

- Final link isa susceptible host

Portalof entry

NewNewHostHost


Noncommunicable Disease Model

Your geneticYour geneticendowmentendowment




Personality

Personality

Beliefs

Beliefs

BehavioralBehavioralchoiceschoices




Personality

Personality

Beliefs

Beliefs

BehavioralBehavioralchoiceschoices

EnvironmentEnvironment Health C

are

Health C

are

System

System

Wat

er Q

ualit

y

Wat

er Q

ualit

y

AirAirPollutionPollution

Eco

nom

ics

Eco

nom

ics


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

• Primary Prevention– is the forestalling of the onset of illness or injury

during the pre-pathogenesis period (before the disease process begins)

• Secondary Prevention– is the early diagnosis and prompt treatment of

diseases before the disease becomes advanced and disability becomes severe

• Tertiary Prevention– is to retrain, reeducate, and rehabilitate the patient

who has already incurred disability


Chapter 4Chapter 4

EpidemiologyEpidemiology::Prevention and Prevention and

Control of DiseasesControl of Diseases and Health Conditionsand Health Conditions

Chap 4: Epidemiology: Prevention and Control of Disease and Health Conditions Anita Sego Spring, 2005.

Documents

control of disease

tertiary prevention

specific communicable

control causative agents

kidney disease

examples of communicable

lyme disease

allocation of prevention