M3L3: Tools in Public Health (Epidemiology)

Epidemiology

The study of the distribution and determinants of health-related states of events in specified populations and the application of this study to the prevention and control of health problems (Last, 1988)

Epidemiology

The study utilizes concepts and methods form other fields of study such as biology, sociology, demography and environmental science and statistics.

Study

(Epidemiology)

surveillance, observation, research, and experiments

Distribution

(Epidemiology)

time, places, and groups of people affected

Determinants

(Epidemiology)

physical, biological, chemical, economic, genetic, and behavioral factors that affect health

Health-related States/Events

(Epidemiology)

disease, cause of death, lifestyle, and use of health services

Specified Populations

(Epidemiology)

Identifiable characteristics (e.g. Occupational hazards)

Application to Prevention and Control

(Epidemiology)

Address the aim of public health: to promote, to protect, and restore health

Epidemiologist

A person who studies epidemiology

Public Health Surveillance

The ongoing systematic collection, analysis, and interpretation of health related-data needed for the planning, implementation, and evaluation of public health practice

Public Health Surveillance

HCW may take an active or passive role

Notifiable Disease Reporting System (NDRS)

Field Health Service Information System (FHSIS)

National Epidemiology Sentinel Surveillance System (NESSS)

Expanded Program on Immunization (EPI) Surveillance System

HIV-AIDS Registry

(5) Philippine Integrated Disease Surveillance and Response

Law on Reporting of Notifiable Disease

R.A. 3573

R.A. 3573

Law on Reporting of Notifiable Disease

R.A. 11332

R.A. 3573 was repealed with a new law ___ ___

"Mandatory Reporting of Notifiable Diseases and Health Events in Public Health Concern Act"

R.A. 11332

R.A. 11332

"Mandatory Reporting of Notifiable Diseases and Health Events in Public Health Concern Act"

Disease Outbreak

The occurrence of disease in excess of what would normally be expected in a defined community geographical area or season

Disease Outbreak

also considered a previously unknown disease

Assessment of the health system of the community

Elucidation of the natural history of disease

Determination of disease causation

Prevention and control of disease

Monitoring and evaluation of health intervention

Provision of evidence for policy formulation

(6) Practical application of Epidemiology

Multiple causation theory

Natural history of disease

Levels of prevention of health prevention

Concepts of causality and association

(4) Concepts in epidemiology

Multiple Causation Theory

(Concepts in Epidemiology)

Disease development does not rest on a single cause but rather results from multiple factors.

Ecologic Triad (Triad of Epidemiology)

(Concepts in Epidemiology: Multiple Causation Theory)

Models in disease causation
- most helpful to the nurse because it highlights not only the host’s and agent’s roles in disease development but also regards the role of environment as important in disease causation.

Agent

Host

Environment

(Concepts in Epidemiology: Multiple Causation Theory)

(3) Ecologic Triad (Triad of Epidemiology)

Agent

(Concepts in Epidemiology: Multiple Causation Theory - Ecologic Triad (Triad of Epidemiology))

Models in disease causation
- is any element, substance, force animate or inanimate which serve as a stimulus to initiate or perpetuate a disease process.

Agent

(Concepts in Epidemiology: Multiple Causation Theory - Ecologic Triad (Triad of Epidemiology))

Models in disease causation
- Biological
- Physical
- Chemical
- Mechanical
- Nutritive

Host

(Concepts in Epidemiology: Multiple Causation Theory - Ecologic Triad (Triad of Epidemiology))

Models in disease causation
- is any organism that harbors and provide nourishment for another organism

Host

(Concepts in Epidemiology: Multiple Causation Theory - Ecologic Triad (Triad of Epidemiology))

Models in disease causation
- Demographic characteristics
- General health status
- Body defenses
- State of immunity & immunological response
- Human behavior

Environment

(Concepts in Epidemiology: Multiple Causation Theory - Ecologic Triad (Triad of Epidemiology))

Models in disease causation
- the sum total of all external conditions and influences that affect the life and development of an organism

Physical

(Concepts in Epidemiology: Multiple Causation Theory - Ecologic Triad (Triad of Epidemiology))

Models in disease causation
- Environment
: inanimate surroundings such as the geophysical conditions and climate

Biological

(Concepts in Epidemiology: Multiple Causation Theory - Ecologic Triad (Triad of Epidemiology))

Models in disease causation
- Environment
: living things such as plants and animal life (vectors)

Socio-economic

(Concepts in Epidemiology: Multiple Causation Theory - Ecologic Triad (Triad of Epidemiology))

Models in disease causation
- Environment
: economic development, social disruptions

Iceberg Principle

(Concepts in Epidemiology: Multiple Causation Theory)

describe a situation in which a large percentage of a problem is subclinical, unreported, or otherwise hidden from view.

Web of Causation

(Concepts in Epidemiology: Multiple Causation Theory)

shows the relationship between different multiple factors that contribute to the cause of a disease

Natural History of Disease

(Concepts in Epidemiology)

Seeks to identify factors related to the course of a disease once established in order to determine its duration and the probability of recovery, death, or specific complications.

Natural History of Disease

(Concepts in Epidemiology)

Help the nurse and other people to implement measures to prevent pathologic processes to progress.

Pre-pathogenesis

Pathogenesis

(Concepts in Epidemiology)

(2) Natural History of Disease

Pre-pathogenesis

(Concepts in Epidemiology: Natural History of Disease)

the disease has not developed but factors that favor its occurrence are present.

Pathogenesis

(Concepts in Epidemiology: Natural History of Disease)

The disease that developed into:
- Pre-symptomatic disease or early pathogenesis
- Discernible lesions
- Advanced disease

Pre-symptomatic disease or early pathogenesis

Discernible lesions

Advanced disease

(Concepts in Epidemiology: Natural History of Disease)

(3) Pathogenesis

Pre-symptomatic disease or early pathogenesis

(Concepts in Epidemiology: Natural History of Disease - Pathogenesis)

individual has no symptoms that indicate the presence of illness but in fact, pathogenic changes have begun.

Discernible lesions

(Concepts in Epidemiology: Natural History of Disease - Pathogenesis)

changes may be detectable through sophisticated laboratory tests, during this period and the early signs & symptoms of diseases are developing.

Advanced disease

(Concepts in Epidemiology: Natural History of Disease - Pathogenesis)

anatomical or functional changes have produced recognizable signs & symptoms.

Prevention

(Concepts in Epidemiology)

___ refers to identification of potential problems so that the nurse can minimize or eradicate possible disability or deformity in a population at risk.

Primary Prevention

(Concepts in Epidemiology: Levels of Prevention of Health Problems)

activities directed to the healthy population, focusing on prevention of emergence of risk factors and removal or reduction of risk factors

Primary Prevention

(Concepts in Epidemiology: Levels of Prevention of Health Problems)

strengthen host resistance; interrupt the chain of infection

Primary Prevention

(Concepts in Epidemiology: Levels of Prevention of Health Problems)

surveillance, quarantine, segregation, isolation

Secondary Prevention

(Concepts in Epidemiology: Levels of Prevention of Health Problems)

aims to identify and treat existing health problems at the earliest possible time.

Secondary Prevention

(Concepts in Epidemiology: Levels of Prevention of Health Problems)

control or eradication of the health problem

Secondary Prevention

(Concepts in Epidemiology: Levels of Prevention of Health Problems)

screening, case finding, disease surveillance

Secondary Prevention

(Concepts in Epidemiology: Levels of Prevention of Health Problems)

prompt and appropriate treatment

Tertiary Prevention

(Concepts in Epidemiology: Levels of Prevention of Health Problems)

limits disability progression

Tertiary Prevention

(Concepts in Epidemiology: Levels of Prevention of Health Problems)

the nurse attempts to reduce the magnitude or severity of the residual effects of infectious diseases and non-infectious diseases.

Disease does not occur at random.

Disease has identifiable CAUSAL and PREVENTIVE factors

(Concepts in Epidemiology: Concept of Causality and Association)

(2) Premises

Cause of a disease

(Concepts in Epidemiology: Concept of Causality and Association)

any event, condition, characteristic or combination of these factors that play an important role in producing the disease.

Cause of a disease

(Concepts in Epidemiology: Concept of Causality and Association)

a cause must precede a disease and the ___ ___ ___ ___ must be necessary and sufficient for the occurrence of disease.

Necessary cause

(Concepts in Epidemiology: Concept of Causality and Association)

refers to the fact that the factor must be present for the disease to occur.

Sufficient cause

(Concepts in Epidemiology: Concept of Causality and Association)

indicates that if a factor is present, the disease can occur, but the factor’s presence does not always result in the disease occurrence.

Risk

(Concepts in Epidemiology: Concept of Causality and Association)

probability of an unfavorable event, disease, disability, defect or even death.

Risk

(Concepts in Epidemiology: Concept of Causality and Association)

must be identified and dealt with to prevent diseases.

Association

(Concepts in Epidemiology: Concept of Causality and Association)

concurrence of 2 variables under investigation and are often associated with each other

Predisposing factor

Enabling factor

Reinforcing factor

(3) Factors associated with increased risk of disease

Predisposing factor

(Factors associated with increased risk of disease)

any characteristic of an individual, a community or an environment that predisposes behavior or other conditions related to health.

Enabling Factor

(Factors associated with increased risk of disease)

any characteristic of an individual, group or the environment that facilitates or make possible a certain health behavior or other conditions affecting health.

Reinforcing factor

(Factors associated with increased risk of disease)

any reward or punishment or any feedback following or anticipated as a consequence of health behavior

1. No disease occurs by chance alone because each follows its own recognizable pattern of occurrence.
2. Health is a state of equilibrium, a delicate balance of many factors.
3. Disease causation is complex.
4. Infection is not synonymous with disease
5. Knowledge of the distribution of disease overtime is valuable to the nurse in the community.
6. An epidemic curve is merely a graphic display of disease onsets overtime, hours, days, or weeks.

(6) Principle in Epidemiology

1. Maintain surveillance of the occurrence of notifiable diseases.
2. Coordinate with other team members during an outbreak.
3. Participate in case finding and collection of lab specimen.
4. Isolate cases of communicable diseases.
5. Render or supervise nursing care.
6. Perform and teach household members methods of disinfection.
7. Conduct health teachings.
8. Follow-up cases.
9. Organize, coordinate, and conduct community health education campaign.
10. Refer cases when necessary.
11. Coordinate with other concerned community agencies.
12. Accomplish and keep records and reports and submit to proper office/agency.

(12) Functions of the Nurse in Epidemiology

Descriptive Epidemiology

Analytical Epidemiology

Interventional or Experimental Epidemiology

Evaluation Epidemiology

(4) Phases of Epidemiological Approach

Descriptive Epidemiology

(Phases of Epidemiological Approach)

aims to describe the occurrence of health conditions in the community in terms of the attributes of the people, pattern of disease and characteristics of the place when the disease appeared

Descriptive Epidemiology

(Phases of Epidemiological Approach)

concerned with disease distribution and frequency

Descriptive Epidemiology

(Phases of Epidemiological Approach)

Case finding and screening activities

Analytical Epidemiology

(Phases of Epidemiological Approach)

Attempts to identify the possible factors associated with disease occurrence.

Interventional or Experimental Epidemiology

(Phases of Epidemiological Approach)

aims to test effectiveness of intervention programs designed to prevent and control disease utilizing randomized controlled or clinical trials and field or community trials.

Evaluation Epidemiology

(Phases of Epidemiological Approach)

attempts to measure effectiveness of different health services and intervention programs

Epidemic

Endemic

Hyperendemic

Sporadic

Pandemic

Outbreak

Cluster

(7) Levels of Disease Occurrence

Epidemic

(Levels of Disease Occurrence)

occurs when the proportion of susceptible are high compared to the immunes; increase in disease incidence

Endemic

(Levels of Disease Occurrence)

occurrence of disease that implies habitual presence of disease in a given geographic location

Hyperendemic

(Levels of Disease Occurrence)

occurrence of disease that implies habitual presence of disease in a given geographic location

Sporadic

(Levels of Disease Occurrence)

disease occur every now and then affecting a small number of people relative to the population

Pandemic

(Levels of Disease Occurrence)

global occurrence of a disease affecting several countries or continent

Outbreak

(Levels of Disease Occurrence)

The occurrence of disease in excess of what would normally be expected in a defined community geographical area or season (WHO)

Outbreak

(Levels of Disease Occurrence)

also considered in a previously unknown disease

Cluster

(Levels of Disease Occurrence)

refers to an aggregation of cases grouped in place in time that are suspected to be greater than the number expected

Herd immunity

Exposure or Contact Rate

Chance

(3) Determining characteristics of the community and population

Herd Immunity

(Determining characteristics of the community and population)

represents the immunity and susceptibility levels of the population

Herd Immunity

(Determining characteristics of the community and population)

occurs when a high percentage of the community is immune to a disease (through vaccination and/or prior illness), making the spread of this disease from person to person unlikely.

Exposure or Contact Rate

(Determining characteristics of the community and population)

represents opportunities for progressive transfer or transmission of an infectious agent to a susceptible host

Exposure or Contact Rate

(Determining characteristics of the community and population)

depends on the frequency of contact and facility of transmission.

Chance

(Determining characteristics of the community and population)

is the probability pf contact between the source of infection and the susceptible host