Epidemiology and the Nurse

Epidemiology

• Epi (upon) & Demos (People)

– Descends among the People.• Branch of Medical Science that deals with

the incidence, distribution, and control of disease in population (Miriam Medical Dictionary)

• The sum of factors controlling the presence or absence of disease or pathogen.

Other Definition of Epidemiology

- is the “Science which give firstly, a picture of occurrence, distribution and types of the diseases of mankind its distinct epochs of time and at various points of earth surface.” (Hirsch)

- Field of medical science which is concerned with relationship of the various factors and conditions which determine the frequencies and distributions of an infection process, a disease or a physiologic state in human community. (Maxcy)

- Is the systematic, scientific study of distribution, pattern and determinants of health, disease and condition frequencies in population, for the purpose of promoting wellness and preventive disease conditions. (Dizon, 1979)

Aspect of EpidemiologyAspect of Epidemiology

• Epidemiology as Descriptive ScienceEpidemiology as Descriptive Science– It Collect Facts to describe the occurrence and distribution

of disease in population, and orients in terms of that variables of person, time and place. It seek to analyze the various factors pertaining to the agent, host and environment and interrelate such factors into the natural history of disease and this discover any gaps in the knowledge on the disease and its control.

• Epidemiology as a Constructive ScienceEpidemiology as a Constructive Science– It does not only describe disease occurrence, but seeks to

explain such occurrence; it does not only present the gaps in the available knowledge on the disease, but more important it seeks to construct new knowledge so as to fill in the gaps in the natural history of the disease.

The Descriptive & Constructive Aspect of Epidemiology

EPIDEMIOLOGYScience Concerned with Factors and Condition which determine occurrence and distribution of health, disease, defect, disability and death in population

Body of Existing KnowledgeDescriptive – Analytic Epidemiology

Method of Gaining new KnowledgeConstructive Epidemiology

Collection of Information for Analysis1. General Factors influencing occurrence and distribution of disease2. Description occurrence & distribution of disease3. Natural History of Disease

Epidemiologic InvestigationsSteps of the Epidemiologic Method1.Definition of problem&clarification of objectives2. Critical Appraisal of existing information3. Formulation of HypothesesVerification of Hypotheses5. Practical Application

ACTION

To discover gaps in knowledge by:

1. Historical Study of disease occurrence2. Community diagnosis of health and disease3. Estimation of rise of morbidity and mortality

1. Searching for causes of disease processes2. Observing the range, aptitude, and group behavior or clinical syndromes in population3.. Evaluate the effectiveness of preventive program

More Effective Preventive Medicine

Graphical Explanation of Epidemiology

Epidemiological ProcessUltimate Goal: Promote Wellness

and prevent disease and condition occurrence

Epidemiology – Systematic

Study of Disease

I. Determine the Nature, Extent and Scope of the Problem

II. Formulate Tentative Hypothesis

III. Collect and Analyze further data to Test Hypothesis

IV. Plan for Control

VI. Plan for Control

V. Implementation of Control Plan

VII. Appropriate Reporting

VIII. Conduct Research

Comparison of Nursing Process and Epidemiological Process

Nursing Process Epidemiological Process

Assessment - Data Collection to determine nature of client problems

I. Determine the Nature, Extent and Scope of the Problem.

A. Natural life History of Condition

B. Determinants influencing condition 1. Primary data (Essential agent)

a. Parasite/bacterium/virus

b. Nutritional

c. Psychosocial

2. Contributory Patterns

a. Agent

b. Host

c. Environment

C. Contribution Patterns 1. Person

2. Place

3. Time

D. Condition Frequencies 1. Prevalence

2. Incidence

3. Other Biostatistical Measurement

Nursing Process Epidemiological Process

Analyzing – Formulation of Nursing Diagnosis II. Formulate/ Develop tentative hypotheses.

III. Collect and analyze further data to test hypotheses

Planning IV. Plan for Control

Implementation V. Implement Control Plan

Evaluation VI. Evaluation Control Plan

Revising or Terminating VII. Make Appropriate Report

Research VIII. Conduct Research

I. Determine the Nature, Extent and Scope of the Problem.

A. Natural life History of Condition

Person-Place-Time RelationshipPerson – who is affectedPlace – where is affectedTime – when affectedWhen monitoring incidence of infectious disease, relative frequency in time

and space are terms as:

Sporadic – There is intermittent occurrence of a few isolated and unrelated cause in a given locality, seasonal/periodical

Endemic – There is continuous occurrence throughout the period of time of usual number of cases in a given locality

Epidemic – the occurrence of unusual large number of cases in relatively short period of time, most interesting for study because the element of urgency is involved.

Pandemic – there is simultaneous occurrence of epidemics of the same disease in several countries of international perspective. Health education on the nature and occurrence of the communicable disease and on personal hygiene, lessen the primary care nurse duty.

Epidemiological TriangleEpidemiological Triangle

Host – Agent – Environment RelationshipsHost – Agent – Environment Relationships

AgentAgent – Animate or inanimate factor that must be – Animate or inanimate factor that must be present or lacking for a disease or condition to present or lacking for a disease or condition to occur.occur.

Host Host – Living species (human or other animals) – Living species (human or other animals) capable of being infected or affected by an capable of being infected or affected by an agentagent

EnvironmentEnvironment – Everything external to a specific – Everything external to a specific agent and host, including humans and animalsagent and host, including humans and animals.

Epidemiological Epidemiological TriangleTriangle

HOST

EnvironmentAgent

Leavell and Clark: Leavell and Clark: Natural History of DiseaseNatural History of Disease

• Prepathogenesis – Exposure to predisposing factor or stimuli which would cause disequilibrium or disease

• Pathogenesis – host not able to overcome the stimuli. There are changes in human and the start of disease process.

Three Phases of Prevention

1. Primary Prevention – accomplished in the Prepathogenesis period of the natural history of disease. Design to promote general optimum health or by specific protection of man against agents or establishment of barriers against agents in the environment

a. Health Promotionb. Specific Protection

2. Secondary prevention – it happened as soon as the disease process is detectable early in pathogenesis.

a. Early Diagnosis and Prompt Treatment

3. Tertiary Prevention – Corrective therapy prevention that accomplished as the pathogenesis progresses.

a. Disability Limitationb. Rehabilitation

Natural History of Any Disease Process in Man

Prepathogenesis Period

Before Man is Diseased

Environmental Factors which produce disease stimulus

Primary Prevention

Pathogenesis Period

The Course of the Disease in Man

Secondary Prevention Tertiary Prevention

HumanHost

Environm

ent

DiseaseAgent

Earlypathogenesis

DiscernibleEarly disease

Advanced disease Convalescence

Recovery

Chronic State Disability

Death

Health Promotion

Specific Protection

Early DiagnosisAnd PromptTreatment

Disability Limitation

Rehabilitation

Step 1:

Determine the Nature, Extent and possible significance of the problem

Step 2: Develop Tentative hypotheses

A hypotheses defined for this purpose, as a tentative theory or supposition provisionally adopted to explain facts and to guide in further investigation.

Step 3: Collect and Analyze Further Data to Test Hypotheses

• Identify the group selected for attack by the disease or problem under investigation.Individual epidemiological health histories should be done to classify person according to their exposure to suspected or causative agents.

Step IV: Plan for Control

• When planning for control, it is essential to identify preventive activities based on the knowledge of the natural history of the disease in question, which can be used to control further spread of disease occurrence.

Chain of Infection

Chain of Infection

Etiologic Agent HostTransmission

Pathogenecity

Infection Dose

Resevoir

Source

Contact

Common Vehicle

Airborne

Vector

Individual Host Factor

Non-specific Resistance

Specific Immunity

Pathogecity - An ability of agent to cause disease. (Virulence + Invasiveness)

a. Virulence – Severity of Infection

Virulence = Morbidity

Mortality

b. Invasiveness – Ability of organism to invade tissue. (Influence by susceptibility

of host.)

Pathogecity

Infection Dose – No of organism necessary to cause disease.

Reservoir – were the organism resides, metabolizes and multiply.

Method of Transmission: Contact Transmission

Common Vehicle Transmission

Airborne Transmission

Vector borne Transmission

Duties and Responsibilities of Duties and Responsibilities of Epidemiological NurseEpidemiological Nurse

1. Maintains surveillance of the occurrence of notifiable disease.

2. Coordinates with other members of the health team during disease outbreak

3. Participates in case findings and collection of laboratory specimens.

4. Isolate cases of communicable disease5. Renders nursing care, teaches and supervises

giving of care6. Perform and teach household members

method, concurrent, and terminal disinfection.

Duties and Responsibilities of Duties and Responsibilities of Epidemiological NurseEpidemiological Nurse

7. Gives health teachings to prevent further spreads of disease to individual and families.

8. Follow up cases and contacts.9. Organizes, coordinates and conducts

community health education campaign/meetings.

10. Refers cases when necessary11. Coordinates with other concerned community

agencies.12. Accomplishes and keeps records and reports

and submits to proper office or agency.