chapter 10 Principles of disease and eidemiology (diana's verision) Flashcards
Principles of disease:
Pathology
describe what is means
the study of disease
we are concerned with the ethiology and pathogenecity
what is ethiology?
this is the primary concern, the cause of the disease
what is pathogenecity?
this is the second concern
how the disease develops
infection: the colonization of the body by pathogenic organisms
disease: an abnormal state where body is not capable of performing normal functions
definition of infection
the colonization of the body by pathogenic organisms
definition of disease
abnormal state where body is not capable of performing normal functions
a typical human body has approximately ____ human cells.
approximately 1 x10^-13
as we know a typical human body has 1 x 10^-13 of human cells , how much does it harbors?
harbors approximately 1 x 10^-14
define what transient microbiota mean
microbes that may be present for days or months and then disappear
The microflora is localized in certain regions of the body, where is this generally found? and inlude examples of its specificity
this is usually found in expose areas, such as skin, respiratory, intestinal, and urinary tracts all of which are exposed to the outside world
what are the role of microbiota (name 2) and then include the category that undergoes this function
benefit the host by preventing the growth of pathogens
other benefits of the microflora
e.coli in the large intestine makes vitamin K and vitamin B (major source)
competitive exclusion
microbial antagonism
define what competitive exclusion, include an an example
microflora uses up the nutrients so it can prevent growth of pathogens
example: clostridium difficile is inhibited by normal microflora of the large intestine
if the normal microflora is eliminated because of antibiotic treatment C.difficile can cause infection
this c.difficle infection can lead to fatal inflammation of the colon
_______ are microbes that are aprt of the normal microflora and do not nomrally cause disease
opportunistic pathogen
oppurtunistic pathogens can cause disease if:
they are transferrred to anothher part of your body
the human host becomes immunocompromised (AIDS)
the normla microflora is disturbed
name some example of oppurtunistic pathogen
E.coli is normal resident of the large intestine , if its transferred to the urinary tracts can cause infection
what is this describe, what kind of pathogen:
streptococcus pneumoniae is a normal resident of the respiratory tract , when a host is already weakened such as a following cold it can cause pneumonia
opportunistic pathogen
etiology : the cause of disease
these allow the determination of the specific microorganisms that cause disease , name what it is describing, and the steps.
this is koch’s postulates theory
the steps:
1.isolate
2.grow in pure culture
3.inoculate in a healthy lab rat or something
4. re-isolate again and match with the o.g microorganism
exceptions to koch’s postulates
1) some bacteria will not grow in pure culture
treponema pallidum : causative agent of syphilis
2) some pathogens cannot used to infect lab animals
HIV
3) sometimes several different microorganims can cause the same disease
pneumonia
4) sometimes one pathogen can cause many different diseases
streptococcus pyogenes : causes strep throat, skin infections, scarlet fever
classification of disease : name the three terms
symptoms
signs
syndrome
define what signs means
an objective change that a physician can measure
ex : lessions, swellingfever,paralysis
define what symptoms means
what the patient is feeling
for example : mailase (rundown feeling) , pain
define what syndrome means
a specific group and symptoms that always accompany a particular disease
True or false.
Diseases cannot be classified based on their effects on host populations?
true….. sike it’s false duh
A disease that spreads from one host to another is called _____, name some example as well.
it’s called communicable disease, for example chicken pox, measles , STD’s
this is also define as ‘ easily spread’, include some examples
contagious disease, chicken pox, and measles
this does not spread, include an example
non-communicable disease salmonellosis
occurence of disease:
name all the term
sporadic
endemic
epidemic
pandemic
emerging infectious disease
what does sporadic mean
disease occurs only occasionally
disease that only occurs occsasionally
sporadic
low and constant levels of disease for example malaria and common cold
endemic
define what endemic means
low and constant levels of disease for example malaria and common cold
define what epidemic means :
disease occurs in high numbers in a short time, for example : influenza,
epidemic disease that occurs worldwide
pandemic, for example influenza, bird flu
define what emerging infectious disease:
newly identified, notable number of cases
ex: west nile virus, SARS
name the three terms for severity or duration of disease
acute
chronic
latent
define what acute
short time, rapidly developing
define what latent means
inactive for a period of time, can be reactivated
example : cold sores, herpes simplex virus-I
define what chronic means
slow to develop, continual duration
extent disease:
local infection
confined to a small area of the body
microbes or toxin that is spread all around the body, name the four example of this term
this term is known as systematic infection
septicemia
bactericemia
toxemia
viremia
deifne what systematic mean
microbes or toxin that is spread all throughout the body
what does septicemia mean
systematic infection of the blood
define what bacteremia mean
bacteria in the blood
define what toxemia mean, define the example
toxic in the blood
clostridum tetnani causes an infection in the cut
tetanus toxin into your blood
what are teh stages of disease
incubation period
prodromal period
period of illness
period of decline
period of convalescence
the time in between the infection and the first signs or symptoms
incubation period
define what prodromal period mean
early and mild symptoms such as malaise
period of illness
most severe signs and symptoms
active immune response may cause signs or symptoms such s fever and if disease is not overcome =death
signs and symptoms subside, can last or hours or days
and patient is vulnerable to secondary infections
period of decline
a person can continue to carry the pathogen for months, and they may be pathogen that are still present and spread to others
period of convalescence: recovery occurs
name what this statement is describing :
this is the source of the infectious agent
this is called a reservoir, and can be object, foods, living things, etc.
people can harbor pathogens and transmit them to tohers and germs may be transmitted during any stage of disease
human resorvoirs
define what human resorvoirs mean
people can harbor pathogens and transmit them to others and germs may be transmitted during any stage of disease
people can also transmit pathogens without having any signs of disease themselves and are called
carriers, such as typhoid mary:s almonella typhi
name the two types of how to spread of infection
1) animal reservoirs
2) non-living reservoirs
Animal Reservoirs: Zoonosis:
disease that occurs in animals but can be transmitted to humans
example: influenza in birds and pigs
rabies in bats, skunks, foxes, etc
lyme disease in field mice: transmitted by Ticks
define non-living reservoirs :
what are the most important examples
soil and water, clostridium tetani found in soil leads to Tetanus in human when the bacteria enters the body through a cut
true or false. Fomites are any non-living obect that spreads pathogens
example: kleenex, used syringes
true
there are three principle routes of transmission:
1) contact transmission
2) vehicle transmission
3) vector transmission
what are the three subgroups of contact transmission
1) direct
2) indirect
3) droplet
define, direct contact transmission
person to person example : chlamydia and other STDs
define indirect (contact transmission)
through fomites
define droplet (contact transmission)
spread by short distance (less than 1 meter)
example : coughing, sneezing, talking, influenza
vehicle transmission and describe it’s characteristics
pathogens transmitted by a medium
i) waterborne
ii)airborne
iii)foodborne
what are the subgroups of vehicle transmission
waterborne
airborne
foodborne
describe what waterborne is
example would be e.coli due to improperly treated sewage
describe what airborne is
spread over less than one meter
dust or droplets
example would be mycobacterium tuberculosis
describe what foodborne is
food poisoning , example would be bacillus cereus, salmonellosis
what is dust?
dead cells, (bacteria) this can be inhaled in which can be very bad and dirty
capacity to move the bacteria to another (animal) acts as a bridge
vector transmission
vector transmission and explain it throughly :
animals that carry pathogens from one host to another
what is usually the vector?
insect
name two examples of vector transmission
1) west nile virus
- birds are the reservoir
-mosquitoes are the vector
-humans are the host
2) Lyme disease
- field mice are the reservoir
-ticks are the vector
-humans are the host
what does nosocomial infections mean?
it means that it is a hospital infection, there are a lot of resistant bug and people that are weak
name the characteristics of nosocomial infections
these are hospital acquired infections
these are infections occur in 5-15% of patients
they result from several factors:
-pathogens in the hospital
-immunocompromised (weakened) state of patients
chain of transmission
1) direct contact
2) indirect contact
3)airborne
describe to me, what does direct contact, indirect contact, airborne mean in terms of nosocomial infections
direct contact: staff to patient or patient to patient
indirect contact: through fomites (needles)
airborne : through ventilation systems
true or false.
When you are stress, your immune system goes down?
that is true
what are the three ways to control the spread of disease?
1) hygiene
2) vectors
3) avoidance
true or false.
Proper hand washing is really effective way to remove any contaminants whether that’s bacteria or virus that can cause further complications?
true
name the characteristics of hygiene and it’s contributions
-proper hand washing is the MOST effective way to combat the spread of disease
-proper sterilization, disinfection, and sanitation
-proper preparation of food and water
-proper sanitation and sewage treatment
*understanding that when we cook things, the number of microbes of 0 is unlikely, but you just want to make it safe so when you put it in your body, you are not risking yourself of having infection
cooking your food _______, making sure there are no microbes in that can potentially
sterile
true or false.
It is important for water to get chemically treated, since it’s actually filled with different bacteria
true
Whenever when we talk about _______: basically bridge in the gap one infected animal or human to another infected animal or human
vectors
name the characteristics of vectors
controlling insect vectors
example : mosquito control in west nile spread
dengue is an example of vector
- vaccination of domestic animals
ex: against rabies
describe the characteristics of avoidance
avoid contact with carriers
example : the use of latex gloves
Quarantine: removal of infected individuals from society
example : tuberculosis
name this example, and what kind of controlling the spread of disease technique it’s saying:
basically using gloves, to not be contaminated with teh carriers so in that case if they have hepatitis b or c or HIV , any infectious material really, you do not have a high chance of catching the disease or at atleast you are minimizing perhaps
avoidance (avoidance with carriers)
when someone shows signs of covid or returned to places that has a high numbers of covid is an example of what controlling of the disease?
this is seen as an example of avoidance specifically quarantine
someone who is infected, and removing themselves from society, covid positive patients is an example
Quarantine
example: tuberculosis sanitoriums
people who are vulnerable with serious infection is a good time is a good route patients who are more vulnerable such as immunocompromised, chemotheraphy
they are out into _____ as much as it is required to make sure they are protected
isolation
describe the characteristics of isolation
people who are highly susceptible to a particular disease are isolated
example : bone marrow transplant patients
