Chapter 14 Flashcards
pathology
study of diseases
etiology
cause of a disease
pathogenesis
development of disease
infection
invasion or colonization of the body by pathogens
disease
abnormal state in which the body is not preforming normal functions
the human microbiome begins to established in the
utero
you get microorganisms acquired from
food, people, pets
human microbiome project
analyzes relationship between microbial communities on the body and human health
normal microbiota/flora
permanently colonize the host and do not cause disease under normal conditions
transient microbiota
may be present for days, weeks, or months and then disappear
distribution and composition of normal microbiota are determined by many factors, what are some of these factors
nutrients, physical and chemical factors, host defenses, mechanical factors
microbial antagonism (competitive exclusion)
is a competition between microbes
normal microbiota protect the host by
competing for nutrients
producing substances harmful to invading microbes
affecting pH and available oxygen
when the balance between normal microbiota and pathogenic is upset what can result
disease
the relationship between normal microbiota and host display what type of relationship
symbiosis
symbiosis
the realationship between normal microbiota and the host
commensalism symbiosis
one organism benefits, and the other is unaffected
Mutualism symbiosis
both organisms benefit
parasitism symbiosis
one organism benefits at the expense of the other
opportunistic pathogens
do not cause harm under normal conditions but if there is a change in immunity of health of the host these can cause disease
Kochs Postulates
1. the same __________ must be present in every case of the disease
2. the pathogen must be ________ from the diseased host and grown in pure culture
3. the pathogen from the pure culture must cause the _________ when its inoculated into a healthy susceptible lab animal
4. the pathogen must be isolated from the inoculated animal and must be shown to be the _________ ___________
pathogen, isolated, disease, original organism
Kochs postulates are used to prove the cause of an
infectious disease
some exceptions to kochs postulates
some pathogens can cause several disease conditions
some pathogens cause disease only in humans
some microbes have never been cultured
symptoms
changes in body function that are felt by the patient as a result of disease
signs
changes in a body that can be measured or observed as a result of disease
can symptoms be measured by observer
no, signs can be measured though
examples of signs
fever, lesions, edema
syndrome
specific group of signs and symptoms that accompany a disease
communicable disease
disease that is spread from one host to another
contagious disease
disease that are easily and rapidly spread from one host to another
noncommunicable disease
disease that is not spread from one host to another
incidence
number of people who develop a disease during a particular time period
incidence is the indicator of the
spread of the disease
prevalence
number of people who develop a disease at a specific time, regardless of when it first appeared
prevalence takes into account
new and old cases
prevalence is an indicator of
how seriously and how long a disease affects a population
sporadic disease
disease that occurs only occasionally
endemic disease
disease constantly present in a population
epidemic disease
disease acquired by many people in a given area in a short time
pandemic disease
worldwide epidemic
acute disease
symptoms develop rapidly but the disease lasts only a short time
chronic disease
symptoms develop slowly
subacute disease
intermediate between acute and chronic
latent disease
causative agent is inactive for a time but then activates and produces symptoms
herd immunity
immunity in most of a population
where there is herd immunity outbreaks are limited to
sporadic cases because there is not enough susceptible individuals to support the spread to epidemic proportions
local infections
pathogens are limited to a small area of the body
systemic (generalized) infection
an infection throughout the body
focal infection
infection that began as local infection but is able to enter the blood or lymph vessels and spread to another specific region of the body
spepsis
toxic inflammatory condition arising from the spread of microbes, especially bacteria or their toxins, from a focus of infection
bacteremia
bacteria in the blood
septicemia
also known as blood poisoning, growth of bacteria in the blood
toxemia
toxins in the blood
viremia
viruses in the blood
primary infection
acute infection that causes the initial illness
secondary infection
opportunistic infection after a primary (predisposing) infection
subclinical disease
no noticeable signs or symptoms (inapparent infection)
predisposing factors
make the body more susceptible to disease
examples of predisposing factors
gender
genes
climate
lack of vaccination
fatigue
age
lifestyle
nutrition
medications like chemotherapy
is the development of a disease similar in acute and chronic?
yes
incubation period
interval between initial infection and first signs and symptoms
prodromal period
short period after incubation; early, mild symptoms
period of illness
disease is most severe
period of decline
signs and symptoms subside
period of convalescence
body returns to its predeceased state
reservoirs of infection are __________ sources of infection
continual
human reservoirs
carriers may have inapparent infections or latent diseases
animal reservoirs
zoonoses are diseases transmitted from animals to humans
nonliving reservoirs
soil and water
3 types of transmission of a disease
contact
vehicle
vector
types of contact transmission
direct contact
congenital
indirect contact
droplet
direct contact transmission
requires close association between the infected and susceptible host (EX: kissing)
congenital transmission
transmission from mother to fetus or newborn at birth
indirect contact transmission
spreads to a host by a nonliving thing called a FOMITE (EX: stethoscopes)
droplet transmission
transmission via airborne droplets that travel very short distances (EX: sneezing)
3 types of vehicle transmission
airborne, waterborne, foodborne
vehicle transmission is by an _________ reservoir
inanimate
airborne
spread of infectious agents by droplet nuclei in dust that are capable of traveling more than one than one meter from reservoir to host due to their small size
waterborne
pathogens are spread by water that is usually contaminated with untreated or poorly treated sewage
foodborne
pathogens are transmitted through foods that haven’t been cooked all the way, poorly stored, prepped under unsanitary conditions, can occur via cross contamination
vectors arthropods examples
fleas, ticks, mosquitoes
vectors transit disease by what 2 methods
mechanical, biological
mechanical transmission
arthropod carries pathogen on its feet
biological transmission
pathogen reproduces in the vector; transmitted via bites or feces
HAIs/Nosocomial infections
acquired while receiving treatment in health care facility
5 major types of HAI/nosocomial
UTI
surgical wound infection
lower respiratory infection
cutaneous infection
bactermia
HAI/nosocomial result from
microorganism in the hospital environment
weekend status of the host
chain of transmission in a hospital
compromised host
an individual whose resistance to infection is impaired by disease, therapy, or burns
universal precautions
an approach to infection control to protect workers from HIV, HBV, and other bloodborne pathogens in human blood and certain other body fluids, regardless of a patients’ infection status.
standard precautions
basic, minimum practices
transmission-based precautions
supplemental to standard precautions; designed for known or suspected infections
contact precautions
used for patients with infections that can be passed through contact with body fluids, feces, equipment or contaminated surfaces
droplet precautions
for patients with infections that can be spread through close contact with droplet nuclei
airborne precautions
for patients with infections that can be spread by droplet nuclei over long distances
emerging infectious diseases
diseases that are new, increasing in incidence or showing potential to increase in the near future
most emerging infectious diseases are ___________, of viral origin and likely to be vector borne
zoonotic
EID genetic recombination example
E. coli 0157 and avian influenza (H5N1)
EID evolution of new strains example
vibrio cholerae 0139
EID widespread use of antibiotics and pestisides
antibiotic resistance strains
EID changes in weather patterns examples
hantavirus
EID modern transportation examples
zika virus, chikungunya, west nile encephalitis
EID insect vectors
Ades aegypti, A. albopictus
EID ecological disaster, war, and expanding human settlement
coccidioidomycosis
EID animal control measures
Lyme disease
epidemiology
study of where and when diseases occur and how they are transmitted in populations
epidemiologist roles
determine etiology of disease
identify other important factors concerning the spread of a disease
develop methods for controlling a disease
assemble data and graphs to outline incidence of disease
3 famous people who participated in epidemiology
John Snow
Ignaz Semmelweis
Florence Nightingale
John Snow 1848-49
mapped the occurance of cholera in London
Ignaz Semmelweis 1846-48
showed that hand washing decreased the incidence of puerperal sepsis
Florence Nightingale 1858
showed that improved sanitation decreased the indigence of epidemic typhus
descriptive epidemiology
collection of data and analysis
who displayed descriptive epidemiology
Snow
analytical epidemiology
analyzes a particular disease to determine its probable cause
who displayed analytical epidemiology
Nightingale
experimental epidemiology
involves a hypothesis and controlled experiments
who displayed experimental epidemiology
Semmelweis
CDC collects and analyzes
epidemiological information in the United States
morbidity
incidence of a specific notifiable disease
mortality
deaths from notifiable diseases
notifiable infectious dieases
diseases that require occurrence reporting by physicians
morbidity rate
number of people affected in relation to the total population in a given time period
mortality rate
number of deaths from a disease in reaction to the population in a given time
