microbiology ch 14 Flashcards
What is pathology?
The study of disease
What is etiology?
The cause of a disease
What is pathogenesis?
The development of disease
What is infection?
Invasion or colonization of the body by pathogens
Can an infection exist in the absence of detectable disease?
Yes
What is disease?
An abnormal state in which the body is not performing normal function
This is the study of disease
Pathology
This is the cause of a disease
Etiology
This is the development of disease
Pathogenesis
This is an invasion or colonization of the body by pathogens
Infection
This is an abnormal state in which the body is not performing normal functions
Disease
What is the human microbiome?
All microorganisms that colonize the human body
When is the human microbiome established?
In utero and during birth
What are three sources of additional microorganisms acquired from after utero and birth?
From food, people, and pets
All microorganisms that colonize the human body make up this, which begins to be established in utero and during birth
Human microbiome
This permanently colonize the host and do not cause disease under normal conditions
Normal microbiota
This may be present for days, weeks, or months
Transient microbiota
This analyzes relationships between microbial communities on the body, and human health
Human Microbiome Project
What are four factors that determine the distribution and composition of normal microbiota?
Nutrients, physical/chemical factors, host defenses, and mechanical factors
What two types of bacteria dominate the microbiome as a result of vaginal birth?
Prevalently Lactobacillus and Bacteroides
What type of bacteria dominates the microbiome as a result of cesarean birth?
Staphylococcus aureus
What does the microbiome resemble following cesarean birth?
Human skin
What is microbial antagonism?
Competition between microbes
What are three ways that normal microbiota protect the host?
By competing for nutrients, producing substances harmful to invading microbes, and affecting pH/oxygen levels
According to Koch’s Postulates, what must be present in every case of a disease?
The same pathogen
According to Koch’s Postulates, what must be done with the pathogen from the diseased host?
Isolated and grown in pure culture
According to Koch’s Postulates, what must happen when the pathogen from the pure culture is inoculated into a healthy, susceptible laboratory animal?
Cause the disease
According to Koch’s Postulates, what must be done with the pathogen from the inoculated animal?
Isolated and shown to be the original pathogen
What are Koch’s Postulates used to prove?
The cause of an infectious disease
What are symptoms?
Changes in body function that are felt by a patient as a result of disease
What are signs?
Changes in a body that can be measured/observed as a result of a disease
What is a syndrome?
A specific group of signs and symptoms that accompany a disease
These are changes in body function felt by a patient as a result of disease
Symptoms
These are changes in a body that can be measured or observed as a result of a disease
Signs
This is a specific group of signs and symptoms that accompany a disease
Syndrome
What is a communicable disease?
A disease that is spread from one host to another
What is a contagious disease?
A disease that is easily and rapidly spread from one host to another
What is a disease’s incidence?
The number of people who develop a disease during a particular time period
What is a disease’s prevalence?
The number of people who develop a disease at a specified time, regardless of when it first appeared
What is a sporadic disease?
A disease that occurs only occasionally
What is an endemic disease?
A disease that is constantly present in a population
What is an epidemic disease?
A disease acquired by many people in a given area in a short time
What is a pandemic disease?
A worldwide epidemic disease
What is an acute disease?
Disease in which symptoms develop rapidly but the disease lasts only a short time
What is a chronic disease?
Disease in which symptoms develop slowly and are lasting
What is a subacute disease?
Intermediate between acute and chronic
What is a latent disease?
Disease in which causative agent is inactive for a time but then activates and produces symptoms
What is herd immunity?
Immunity in most of a population
What is a local infection?
Infection in which pathogens are limited to a small area of the body
What is a systemic (generalized) infection?
An infection throughout the body
What is a focal infection?
Systemic infection that began as a local infection, arising from areas such as teeth, tonsils or sinuses
What is sepsis?
Toxic inflammatory condition arising from the spread of microbes from a focal infection
What is bacteremia?
Bacteria in the blood
What is septicemia?
Growth of bacteria in the blood
What is toxemia?
Toxins in the blood
What is viremia?
Viruses in the blood
What is a primary infection?
Acute infection that causes the initial illness
What is a secondary infection?
Opportunistic infection after a primary infection
What is a subclinical infection?
Infection with no noticeable signs or symptoms
What is the incubation period?
Interval between initial infection and first signs and symptoms
What is the prodromal period?
Short period after incubation characterized by early, mild symptoms
What is the period of illness?
Period when disease is most severe, characterized by overt signs and symptoms
What is the period of decline?
Period when signs and symptoms subside, lasting 24 hours to several days
What is the period of convalescence?
Period when body returns to its pre-diseased state and recovery has occurred.
What is contact transmission?
The spread of a disease agent by direct contact, indirect contact, or droplet transmission
What is vehicle transmission?
Transmission of a disease agent by a medium such as air, water, or food
What is vector transmission?
Transmission of a disease agent by an animal carrying pathogens from one host to another
What are the four types of contact transmission?
Direct contact, congenital, indirect contact, and droplet
What is a nonliving object that spreads a disease causing agent to a host in indirect contact transmission?
Fomite
What are the three types of vehicle transmission?
Airborne, waterborne, and foodborne
What are the two general methods of vector transmission?
Mechanical transmission and biological transmission
An arthropod carrying a pathogen on its feet is an example of this type of vector transmission
Mechanical transmission
A pathogen reproducing in the vector, then transmitting through a bite or feces is an example of this type of vector transmission
Biological transmission
These are also known as nosocomial infections
Healthcare-associated infections
What is the ratio of patients affected by nosocomial infections?
1 in 25
What are three factors that can result in healthcare-associated infections?
Microorganisms in the hospital environment; weakened status of the host; chain of transmission in a hospital
These are diseases that are changing or new, increasing in incidence, or showing a potential to increase in near future
Emerging infectious diseases
What are three characteristics of most emerging infectious diseases?
Zoonotic, of viral origin, and vector-borne
This is the study of where and when diseases occur and how they are transmitted in populations
Epidemiology
What does descriptive epidemiology involve?
Collection and analysis of data
What does analytical epidemiology involve?
Analysis of a particular disease to determine its probable cause
What does experimental epidemiology involve?
A hypothesis and controlled experiments
What is morbidity rate?
Number of people affected in relation to the total population in a given time period
What is mortality rate?
Number of deaths from a disease in relation to the population in a given time
What are notifiable infectious diseases?
Diseases whose occurrence physicians are required to report
