F-PRINCIPLES OF DISEASE AND EPIDEMIOLOGY Flashcards
branch of medicine which deals with the incidence, distribution, and possible control of diseases and other factors relating to health.
Epidemiology
scientific study of disease
Pathology
____=suffering
_____= science
pathos
logos
the manner in which a disease develops
Pathogenesis
ability of an organism to cause disease;
Pathogenecity
invasion or colonization of the body by pathogenic microorganisms
Infection
occurs when an infection results in any change from a state of health
Disease
what are the six involved in the chain of infection
causative agent reservoir portal of exit method of transmission portal of entry host
what are examples of a reservoir
humans
animals
soil
water
what are causative agents of infection?
bacteria fungi viruses protozoa helminths
what are the portals of exit?
gastrointestinal tract urogenital tract upper respiratory tract blood broken skin mucous membrane
what are some methods of transmission
indirect/direct contact airborne food water body fluids
what are some of the portal of entries
gastrointestinal tract urogenital tract upper respiratory tract blood broken skin mucous membrane
susceptible host can be any person; patient, client, or health worker
host
any person, animal, arthropod, plant, soil or substance in which an infectious agent normally lives and multiplies, on which it depends primarily on survival.
RESERVOIR
this type of reservoir include people, insects, birds, and other animals
ANIMATE RESERVOIR
this type of reservoir include soil, water, food, feces, and intravenous fluid and equipment
INANIMATE RESERVOIR
what are the ways we can break the chain of infection?
elimination of sources of infection (reservoir)
appropriate handling of contaminated items,
appropriate handling and disposal of body secretions
site from where micro-organisms leave the host to enter another host and cause disease/infection
PORTAL OF EXIT
the movement of the transmission of pathogens from a reservoir to a susceptible host.
METHOD OF TRANSMISSION
also known as person-to-person contact.
DIRECT CONTACT
nonliving object used to transmit the pathogen to a susceptible host.
INDIRECT CONTACT
this is what you call the objects that can transmit pathogens
FOMITE
pathogens are spread in mucus droplet that travel only short distances, usually less than one meter from reservoir to host, discharged into air by coughing, sneezing, laughing, or talking
DROPLET TRANSMISSION
pathogens transmitted by a medium which could be water, food, or air
VEHICLE TRANSMISSION
pathogens are spread by contaminated water
WATERBORNE TRANSMISSION
pathogens are transmitted in foods that are improperly cooked or prepared under sanitary conditions
FOODBORNE TRANSMISSION
pathogens are spread by droplet nuclei in dust that can harbor more than 1 meter from the reservoir to the host. Dust particles can harbour many different types of pathogens. Droplets which are small enough can remain suspended in air for hours and carried by dust or air
AIRBORNE TRANSMISSION
are arthropods that carry pathogens from one host to another
VECTORS/ VECTORS TRANSMISSION
occurs when there is a passive transport of pathogen from insect to the host (flies)
MECHANICAL TRANSMISSION
occurs when there is a passive transport of pathogen from insect to the host (flies)
MECHANICAL TRANSMISSION
active process of pathogen transmission for example an insect bite, ingesting its blood and later the pathogen inside the insect reproduce multiple times. EX. dengue and malaria
BIOLOGICAL TRANSMISSION
The site through which microorganisms enter thee susceptible host and cause disease/infection, mucous membrane, skin, respiratory, gastrointestinal tracts
PORTAL OF ENTRY
T OR F: pathogens often enter the body of the host through the same route they exited the reservoir
T
human body; someone who is at the risk of infection
HOST
acquired immunity can be broken down into two what are they?
natural and Artificial
what are NATURAL acquired immunity-
active- clinical disease or subclinical infection
passive- from mother, transplacental antibodies, breastmilk
artificial acquired immunity
active-vaccination
passive- serum containing immunoglobulins
are microorganism that ate capable of causing diseases or infections
CAUSATIVE AGENT
is the branch of medicine which deals with the incidence, distribution, and possible control of diseases and other factors relating to health.
Epidemiology
is also used to search for determinants, which refers to
the causes and other factors that influence the occurrence of disease
and other health-related events. Determinants can be demographic
characteristics, genetic makeup, risk factors, environmental exposure.
Epidemiology
epi-
demi-
ology-
upon
people
study
To understand the full scope of a disease, we should know
something about its occurrence.
LEVEL OF DISEASE
disease (e.g. malaria and dengue) is usually present in a community and this may not necessarily be the desired level.
endemic disease
(e.g. leptospirosis and typhoid fever) disease occurring infrequently
and irregularly,.
sporadic disease
disease or a persistent high levels of disease occurrence
hyperendemic
(e.g. influenza) refers to an increase, often sudden, in the number
of cases of a disease above what is normally expected in that population in
that area.
epidemic
carries the same definition of epidemic, but is often used for a more limited geographic area.
outbreak
(e.g. COVID-19, SARS, MERS-Cov) refers to an epidemic that has spread over several countries or continents, usually affecting a large number
of people
pandemic
SEVERITY OR DURATION OF DISEASE- is one that develops rapidly but lasts only a short time (e.g. influenza).
acute disease
develops more slowly, and the body’s reactions may be less severe, but the disease is likely to continue or recur for long periods (e.g. hepatitis B).
chronic disease
A disease that is intermediate between acute and chronic is described as a _____; an example is subacute sclerosing panencephalitis.
subacute disease
is one in which the causative agent remains inactive for a time but then becomes active to produce symptoms of the disease; an example is shingles, one of the
diseases caused by varicella virus.
latent disease
Once the pathogen overcomes the defenses of the host, the
development of a disease follows a definite sequence of events
regardless whether it’s acute or chronic.
STAGES OF INFECTIOUS DISEASE
the interval between the initial infection and the first appearance of any signs or symptoms. The time of ________ depends on the specific microorganism involved, its virulence (degree of pathogenicity), the number of infecting microorganisms, and the resistance of the host.
Incubation period
– characterized by early, mild symptoms of disease,
such as general aches and malaise. This is short period that follows the
period of incubation in some diseases.
Prodromal period
the period where disease is most severe. The person exhibits overt signs and symptoms of the disease contracted. If the patient’s immune system cannot overcome the pathogen present, the patient dies.
Period of Illness
also known as the period of effervescence. This is period where signs and symptoms begin to subside but the patient may be vulnerable to secondary infections.
Period of Decline also known as defervescence
this period marks the patient’s recovery
from the disease. The patient regains strength and body returns to its
normal condition.
Period of Convalescence
subjective changes that are not apparent to an observer.
Symptoms
objective changes the physician can observe and measure.
Signs
specific group of symptoms or signs, a combination of signs and symptoms
Syndrome
spreads from one host to another. (e.g. Chickenpox, measles, genital herpes, typhoid fever, and tuberculosis)
Communicable disease
not spread from one host to another. (e.g. tetanus, diabetes)
Noncommunicable disease
how do we classify infectious diseases?
symptoms, signs, syndrome, communicable disease, noncommunicable disease
