Epidemiology & communicable disease Flashcards
“the study of the occurrence and distribution of health-related states or events in specified populations, including the study of the determinants influencing such states, and the application of this knowledge to control the health problems.”
epidemiology
epidemiology includes:
communicable and chronic disease, mental health, occupational health and injuries
seeks to describe the distribution of health-related states and events in terms of person, place, and time.
descriptive epidemiology
focuses on investigation of causes and associations.
analytic epidemiology
is the broad consideration of many levels of potential determinants from different sources (systems approach).
ecologic approach
describes who has the disease; where and when it occurs.
distribution
occurs when the rate of disease, injury, or other condition exceeds the usual (endemic) level of that condition.
epidemic
Example of descriptive epidemiology
illustrating the current prevalence of ebola virus is Western Africa
Example of analytic epidemiology
when you are investigating the cause of an outbreak of vomiting and diarrhea after a large banquet and you test the food eaten - focuses on the determinants of health-related states and events.
is a measure of the frequency of a health event in different populations at certain periods
rate
is the probability that an event will occur within a specified period
risk
a measure that reflects the number of new cases or events in a population at risk during a specific time period
incidence
a measure of existing disease in a population at a particular time
prevalence
a measure of illness severity
morbidity rate
a measure of deaths
mortality rate
natural vs acquired immunity
natural = innate resistance
acquired = disease resistance from having a disease or vaccination
core epidemiologic functions**
Surveillance
Field investigations
Analytic studies
Evaluation
about the outcomes of an intervention or program under ‘ideal’ conditions, such as studying outcome in a research study
only measures the outcomes in the people who participate in the program.
efficacy
about the outcomes in ‘real world’ settings, such as when a program is implemented in a community or a clinical setting
effectiveness
the ongoing, systematic collection, analysis, interpretation, and dissemination of health data to help guide public health decision making and action.This happens through the collection and evaluation of morbidity and mortality reports and other relevant health information, the dissemination of these data, and their interpretation for public health decision making.
public health surveillance
provides information for action: it identifies disease trends and patterns, enables resource priorities to be decided, and lead to the planning of health programs as well as evaluation methods.**
surveillance
used to identify and describe the distribution and determinants of health-related states and events, as well of the efficacy, effectiveness, and efficiency of health intervention and health services
investigative functions
Causes of health-related stated and events
Identifying Risk factors for health-related stated and events
Address the role of epidemiological work in informing health policy and all levels
policy
Emphasizes the importance of linkages across professions, organizations, governments, and other necessary parties
linkages
web of causality
A two-dimensional causal web that considers multiple levels of factors that affect health and disease
What might be the “spider” in web of causality
those larger factors and contexts that influence or create the causal web itself
Poverty, discrimination, and other social determinants
what is epidemiologic data
primary data from sources such as surveys and interviews; secondary data research findings and government dashboards
ex of epidemiologic data
Surveys
observations
experiments
questionnaires
interviews.
Government publications, websites, journal articles, internal records
routinely collected data
Census data
Vital records (birth and death certificates)
Surveillance data as carried out by the Centers for Disease Control and Prevention (CDC)
Long-term patterns of morbidity or mortality rates (i.e., over years or decades)
secular trends
Secular trends may reflect changes in social behavior or health practices
Personal characteristics of interest in epidemiology include:
race, ethnicity, sex, age, education, occupation, income (and related socioeconomic status), and marital status.
Place based characteristics are geographic:
how does the rate of disease differ from place to place (e.g., with local environment)
time based considerations
Is there an increase or decrease in the frequency of the disease over time? Are other temporal (and spatial) patterns evident? Temporal patterns of interest to epidemiologists relate to epidemics at singular or certain points in time, cyclical patterns (seasonal), and event-related clusters (such as a food borne illness event after a banquet).
analytic epidemiology
Cohort studies
Case-control studies
Cross-sectional studies
Ecologic studies
Ecologic fallacy
Research issue is commonly the efficacy of a medical treatment for disease
clinical trials
The issue is often health promotion and disease prevention rather than treatment of existing diseass
community trials
Community-oriented epidemiology: Involves
observation, data collection, consultation, and interpretation
A form of epidemiology in which lay people gather scientific data as well as mobilize knowledge and resources of experts to understand the occurrence and distribution of a disease or injury
Popular epidemiology
epidemiologic triangle**
environment
agent
host
The method through which the agent leaves its reservoir and enters its host
exs:
transmission
Water, food, air, vectors, unprotected sexual contact, or penetrating wounds
usually insects that carry the disease from the reservoir to humans
vectors
Inanimate objects that can carry disease, such as a contaminated doorknob,
fomites
transmission of communicable diseases
Agent, host, and environment
Modes of transmission
Disease development
Disease spectrum
Vectors
fomites
resistance to disease
immunity
the ability of the host to withstand infection and it may involve natural (inborn) or acquired (from disease or vaccination) immunity
resistance
likelihood of a human’s risk of disease due to exposure to the disease agent
susceptibility
the resistance of a group of people to an attack of disease to which a large proportion of the members of the group are immune
herd immunity
The immunity of a population to an agent depends upon Having
large enough portion of the population immune (by vaccine or past infection) to prevent the spread of disease to persons in the population who do not have immunity.
The threshold of immunity depends upon The
percentage of the population that must be immune to achieve herd immunity to a specific agent
vertical modes of transportation
Parent to offspring
horizontal mode of transportation
person to person
four routes of horizontal transmission
direct/indirect contact, common vehicle, airborne, or vector-borne
routes of vertical transmission
sperm, placenta, milk, or contact in the vaginal canal at birth
Significant increase in a disease
epidemic
Numbers of diseases within a population
endemic
Outbreaks around the globe
pandemic
the entry, development, and multiplication of the infectious agent in the susceptible host
infection
possible outcomes of infection; may indicate physiologic dysfunction or pathologic reaction
disease
time interval between invasion by an infectious agent and the first appearance of signs and symptoms of the disease
incubation period
interval during which an infectious agent may be transferred directly or indirectly from an infected person to another person
communicable period
a systemic epidemiological investigation can:
-Determine if there is a sudden increase in the incidence of a C D
-Define what constitutes a case
-Determine the severity of the outbreak - case fatality rate
-map out the epidemic curve
-generate a hypothesis
-conduct case finding
-determine common source of exposure
-identify source of transmission on take action
-isolate source
-how best to break the cycle
Increase in emerging and reemerging communicable diseases:
Zika, Ebola, disease resistant Tuberculosis, polio
transmission of TB
airborne droplets
common symptoms of TB
Cough
fever
fatigue
hemoptysis
chest pains
weight loss
cases and death from TB
12 million cases
1.3 million deaths
treatment failure in TB
due to lack of client adherence, which can result in drug resistance. U.S. drug regimens include isoniazid and sometimes rifampin.
goal for preventing and controlling communicable diseases
reduce prevalence and prevention
roles of nurses in prevention and control of communicable diseases
Immunizations
Surveillance
Teaching controls
Prevention
Screening and treatment
vaccine-preventable diseases**
Routine childhood immunization schedule
Measles
Rubella
Pertussis
Influenza
an acute, highly contagious disease that, although considered a childhood illness, may be seen in the United States in adolescents and young adults.
measles
virus causes a mild febrile disease with enlarged lymph nodes and a fine, pink rash that is often difficult to distinguish from measles or scarlet fever. In contrast to measles, rubella is only a moderately contagious illness.
Rubella (German measles)
begins as a mild upper respiratory tract infection progressing to an irritating cough that within 1 to 2 weeks may become paroxysmal (a series of repeated violent coughs). Because of its cyclical nature, there are periodic outbreaks of pertussis.
pertussis (whooping cough)
this viral respiratory tract infection often hard for people to distinguish from the common cold or other respiratory diseases – key: shot campaigns with symptom awareness
influenza
Foodborne and Waterborne Diseases
Role of safe food preparation
Salmonellosis
Escherichia coli
Waterborne disease outbreaks and pathogens
STI transmission
through sexual contact and exchange of bodily fluids; Preventable with Use barrier protection
more than 25 infectious agents
harmful effects of STIs
Reproductive health problems
Fetal and perinatal health problems
Cancer (HPV), associated with the sexual transmission of HIV infection
There are three notifiable STI’s that have federally funded control programs:
chlamydia, gonorrhea, and syphilis
associated with pelvic inflammatory disease and can be passed from mother to the infant during delivery
Chlamydia and gonorrhea
syphilis staging cures
can be cured during the 1st stage; can be passed from mother to the infant during pregnancy or delivery.
most commonly reported infectious disease
chlamydia
vector-borne diseases
tick-borne diseases
lyme disease
rocky mountain spotted fever
Usually occurs in the summer in rural and suburban areas of the northeast, mid-Atlantic, and north-central states, particularly Wisconsin and Minnesota
lyme disease
Most commonly occurs in the southeast, Oklahoma, Kansas, and Missouri
rocky mountain spotted fever
refer to illnesses for which the infectious agent is transmitted by a carrier, or vector, usually an arthropod (mosquito, tick, fly), either biologically or mechanically.
vector-borne disease
an infection transmitted from a vertebrate animal to a human under natural conditions
zoonosis
means of transmission of zoonoses
include animal bites (bats and rabies), inhalation (rodent excrement and hantavirus), ingestion (milk and listeriosis), direct contact (rabbit carcasses and tularemia), and insects.
Highest case fatality rate of any known human infections, essentially 100%. Best protection remains vaccinating domestic animals (dogs, cats, cattle, and horses)
Rabies (hydrophobia)
most common infection in United States, usually in schools, institutions, where overcrowding occurs
pinworm
control and prevention of parasitic diseases
Early diagnosis
improved hygiene and vector control
education and environmental improvements
parasites that live within the body
endoparasites
endoparasites in four main groups:
nematodes (roundworms)
cestodes (tapeworms)
trematodes (flukes)
protozoa (single-celled animals).
Health Care-Associated Infections
Transmitted or developed within a hospital or other health care setting
Transmitted between Clients, Health care workers, Visitors
MRSA (methicillin resistant staphylococcus aureus)
Communicable Disease and Nursing Practice
Nursing practice includes doing your part to prevent the spread of communicable disease
Preventative measures: Personal protective equipment, Proper cleaning of equipment, Preventing transmission to coworkers, self, and other patients
Understand communicable diseases at Individual and Population levels
Public and community health nurses are on the front lines of communicable disease management
