4. Epidemiology and Communicable Disease- Community Nursing

epidemiology

study of health-related trends in populations for the purposes of disease prevention, health maintenance, and health protection

epidemic

An outbreak that occurs when there is an increased incidence of a disease beyond that which is normally found in the population

Epidemiology is used to monitor what?

disease trends

Examining numeric indicators of the occurrence of diseases or conditions, how long they last, and comparing that to historical trends assists with the management

Look how it spreads

Look at the transmission

Plan interventions

Assess the barriers

Educate the public

Calculations provide numerical information about the impact of disease and death on population and aggregates

Community health nurses are in the unique position of being able to do what?

identify cases and recognize patterns of disease, eliminate barriers to disease control, and provide education and counseling targeted at a disease condition or specific risk factors.

Epidemiologic triangle/triad

Model based on the belief that health status is determined by the interaction of the characteristics of the host, agent, and environment

the interaction of the host, agent, and environment helps determine what?

the development and cessation of communicable diseases, as they form a web of causality, which increases or decreases the risk for disease

agent

physical, infectious, or chemical factor that causes the disease

host

living being that an agent or environment influences

environment

setting or surrounding that sustatins the host

wheel of causation

Epidemiologic model that de-emphasizes the agent as the sole cause of disease while emphasizing the interplay of physical, biologic, and social environments

Interaction between the ___________, with or without an identifiable agent, remains the major determinant of health status in all epidemiologic models

host and environment

web of causation

Epidemiologic model that strongly emphasizes the concept of multiple causation while de-emphasizing the role of agents in explaining illness

how is the web of causation different from the wheel of causation?

more focused and realistic, and they may be as intricate and complex as needed. In this model, it is necessary to identify all possible antecedent factors that could influence the development or prevention of a particular health condition

natural history of disease

integrated the pathogenesis of an illness with primary, secondary, and tertiary prevention measures

initial interactions between the agent, host, and environment occur during which period?

prepathogenesis period

primary prevention

measures specific to the disease can be implemented at this stage to prevent its onset in a population of well people

when does the period of pathogenesis begin?

here are biologic, psychological, or other responses within the host

secondary prevention

early diagnosis and prompt treatment

can limit resulting disabilities

tertiary prevention

rehabilitation measures that enable the individual to function at his or her maximum

incidence calculation

number of new cases in the population at a specific time / population total x 1000= ____ per 1,000

prevalence calculation

number of existing cases in the population at a specific time / population total x 1,000= ____ per 1,000

attack rate calculation

number of people exposed to a specific agent who develop the disease / total number of people exposed

crude: overall death rate calculation

Number of deaths / population total x 1,000= _____ per 1.000

cause-specific

death from specific cause

Infant mortality ratio

deaths at specific times across the lifespan

infant mortality calculation

Number of infant deaths before 1 year of age in a year / number of live births in the same year x 1,000= ____ per 1,0000

pandemic

condition occurs when an epidemic occurs in multiple countries or continents

agent defined

Infectious agents are biological in nature and are capable of producing an infection or infectious disease and include bacteria, viruses, rickettsiae, fungi, protozoa, and helminths

virulence

Severity of the infectious disease that results from exposure to the agent; degree in which an organism is able to cause severe pathological reaction; degree of communicability

degree of communicability

time during which an infectious agent may be transferred directly or indirectly from an infected person to another person, from an infected animal to humans, or from an infected person to animals

infectious

Caused by or capable of being transmitted by infection.

human (or animal) host is one caused by the growth of pathogenic microorganisms in the body; starting to reproduce itself in your body

contagious

there must be a portal of exit from the infected person (or animal), a means of transmission, and a portal of entry to a susceptible host; communicable; able to transmit directly or indirectly

pathogencity

Ability of the agent to produce an infectious disease in a susceptible host

endemic

The constant or usual prevalence of a specific disease or infectious agent within a population or geographic area

incubation period

time between exposure to an infectious agent and the manifestation of symptoms in the host

colonization

prescence and multiplication of infectious organisms without invading or causing damage to tissue

surveillance

A continual dynamic method for gathering data about the health of the general public for the purpose of primary prevention of illness

quarantine

secondary prevention method

emerging

newly identified novel infectious disease

reemerging

disease is known to us, declined, and suddenly increase

reservoir

Location where an infectious agent is normally found, where it lives and reproduces under normal circumstances

carrier

A person or animal that harbors an infectious organism and transmits the organism to others, although having no symptoms of the disease

properties of an infectious agent

pathogenicity

infectivity

virulence

toxicity

immunogenicity

invasiveness

pathogenicity

Ability of the agent to produce an infectious disease in a susceptible host

infectivity

Ability of the agent to invade the host and replicate

toxicity

Ability of the agent to produce toxins

immunogenicity

Ability of the agent to produce specific immunity within the host

invasiveness

Ability of the agent to destroy body cells

Populations at Risk of Communicable Disease

Young children

Older adults

Immunosuppressed clients

Clients who have a high-risk lifestyle

International travelers

Health care workers

vertical transmission

sperm, placenta, vaginal contact during birth, or consuming human milk

horizontal transmission

contact with a person or objects the person has touched, the air, contaminated body fluids, food, and water (vehicles), or living creatures like mosquitoes and snails (vectors)-- Zika virus

airborne

particles transmitted by air to susceptible host via droplets or particles

incidence rate

Measure of the probability that people without a certain condition will develop that condition over a period of time

types of airborne diseases

Measles

Chickenpox

Tuberculosis

Pertussis (droplet)

Influenza (droplet)

Severe acute respiratory syndrome (SARS) (droplet)

Food infection (bacterial, viral, parasitic infection of food)

Norovirus

Salmonellosis

Hepatitis A

Trichinosis

E. Coli

food intoxication

toxins produced through bacterial growth, chemical contamination, or disease-producing substances

food intoxication examples

Staphylococcus aureus

Clostridium botulinum

waterborne

fecal contamination of water

waterborne examples

Cholera

Typhoid fever

Bacillary dysentery

Giardia lamblia

vector borne

via a carrier, such as a mosquito or tick

vector borne examples

West Nile virus

Lyme disease

Rocky Mountain spotted fever

Malaria

direct contact

transmission of infectious agent from infected host to susceptible host via direct contact

direct contact examples

STIs: HIV/AIDS, chlamydia, gonorrhea, syphilis, HPV, genital herpes, Hepatitis B,C,D

Infectious mononucleosis

Enterobiasis (pinworms)

Impetigo

Lice, scabies

herd immunity

protection due to the immunity of most community members making exposure unlikely

natural immunity

natural defense mechanisms of the body to resist antigens or toxins

acquired immunity

develops through actual exposure to the infectious agent

active

production of antibodies by the body in response to infection or immunization with a specific antigen

passive

transfer of antibodies to the host either transplacentally from mother to newborn or through transfusions of immunoglobulins, plasma proteins, antitoxins

communicable disease surveillance

Mandated reporting

Descriptive epidemiology

whom/how/when/where/who/why/what

track point of origin

manage disease outbreak

contract tracing

mandated reporting

By state and local regulations and state notification to the CDC is voluntary

descriptive epidemiology

used to investigate disease patterns

whom/how/when/where/who/why/what

Whom it affected /how it occurs /what or why the cause is /where the issue is located /when the condition started

The date is useful in developing public health policies regarding disease management and to...

evaluate efficiency of communicable disease programs (assurance)

National Health Goals and Immunizations

Reduce bad behaviors/practices

Increase healthy behaviors/practices

Track at-risk populations

Education

Current recommendations

Barriers to immunization

common source outbreak

one that has the same origin (i.e., same person or vehicle as the reservoir or means of transmission)

Propagated (continous) outbreak

one in which the infection is transmitted from person to person over a longer period of time than with a common source outbreak, and it can generate secondary infections with intervals between peaks that approximate the usual incubation period for the infection

Communicable/Contagious Disease

Must have portal of exit/infected person/animal

Means of transmission

Portal of entry/susceptible host

chain of infection

Causative agent

Reservoir

Portal of exit

Mode of transmission

Portal of entry

Susceptible host

Repeat

Factors that Impact Emerging Infectious Diseases

microbial adaptation

Susceptibility

Climate change

Politics

Travel

Technology

Infrastructure

Human behavior

microbial adaptation

Process by which organisms adjust and change to their environment

natural history of disease aspects

Onset to resolution

Primary, secondary, tertiary levels of prevention

Biologic, psychological host responses

primary: prepathogenesis period

Prevent occurence

Educate public on immunization

Counsel clients about travel

Educate on eliminating risk factors

Secondary: early diagnosis/treatment

Increase early detection

Provide post-exposure prophylaxis

Quarantine

Contact tracing

Tertiary: rehab/maximun function

Decrease complications and disabilities

Montior treatment compliance

Identify and link clients to needed resources

Zoonotic Disease/Antibiotic Resistant Organism Threats

Zoonotic

Urgent

Serious

Concerning

Antibiotic stewardship

zoonotic

Transmitted to humans through contact with animals and birds

antibiotic stewardship

Refers to a set of coordinated strategies to improve the use of antimicrobial medications with the goal of enhancing patient health outcomes, reducing resistance to antibiotics, and decreasing unnecessary costs