Exam 2 Infection, Infectious Diseases, and Epidemiology Flashcards
This means to live together
Symbiosis
What are the 3 types of symbiosis?
Mutualism
Commensalism
Parasitism
This type of symbiosis is when both organisms benefit
Mutualism
This type of symbiosis is when one organism benefits, and the other organisms doesn’t benefit but isn’t harmed
Commensalism
This type of symbiosis is when one organism benefits, and the other is harmed
Parasitism
Organisms that colonize the body’s surfaces without normally causing disease
Normal microbiota aka
Normal flora
Indigenous microbiota
Remain part of normal microbiota of a person for life
Resident microbiota
Remain in body for few hours, days, months before disappearing
Transient microbiota
Sites that are free of any microbes and are never colonized by normal flora
Axenic
List some examples of axenic sites
Alveoli of lungs CNS Circulatory System Upper Urogenital Regions Uterus
Normal microbiota that cause disease under certain circumstances
Opportunistic pathogens
Sites where pathogens are maintained as a source of infection
Reservoirs of infection
What are 3 types of reservoirs
Animal réservoirs
Human carriers
Nonliving reservoirs
Diseases naturally spread from animal host to humans
Zoonoses
Humans are known as this type of host, since humans can get diseases from animals, but animals do not get diseases from humans
Dead-end host
Infected individuals who are asymptomatic but infective to others
Human carriers
When a human carrier eventually develops the illness
Case
Used to separate ill person who have a communicable disease
Isolation
Used to separate and restrict the movement of well persons who may have been exposed to a communicable disease
Quarantine
What are some nonliving reservoirs?
Soil, water, and food usually from contamination of feces or urine
The mere presence of microbes in or on the body
Contamination
When organism evades body’s external defenses which may or may not result in disease
Infection
Sites through which pathogens enter the body
Portals of entry
What are 3 major portals of entry
Skin
Mucous membranes
Placenta
Technically not a portal of entry, but a way to circumvent the usual portals of entry
Parenteral route
What is the most common site for entry into the body?
Respiratory tract (nose, mouth, eye)
Toxoplasma gondii can cross placenta
Toxoplasmosis
Treponema pallidum can cross placenta
Syphilis
Listeria monocytogenes can cross placenta
Listeriosis
Cytomegalovirus can cross placenta
Asymptomatic in adults
Parvovirus B19 can cross placenta
Erythema infectiosum
Lentivirus (HIV) can cross placenta
AIDS
Rubivirus can cross placenta
German measles
Results if the invading pathogen alters normal body functions (morbidity)
Disease
Ability of a microorganism to cause disease
Pathogenicity
Degree of pathogenicity (how easy is it for the organism to cause disease)
Virulence
The ability of a substance to stimulate the production of antibodies or cell-mediated immune response
Antigenicity
Subjective characteristics of disease felt only by the patient
Symptoms
Objective manifestations of disease observed or measured by others
Signs
Group of symptoms and signs that characterize a disease or abnormal condition
Syndrome
carcino-
cancer
col-,colo-
colon
dermato-
skin
-emia
pertaining to the blood
endo-
inside
-gen, gen-
give rise to
hepat-
liver
idio-
unknown
-itis
inflammation of a structure
-oma
tumor or swelling
-osis
condition of
-patho, patho-
abnormal
septi-
literally rotting; refers to presence of pathogens
terato-
defects
tox-
poison
What is the triad or triangle of health contain?
Host
Agent
Environment
What results when the triangle of health is in balance?
Health
What results when the triangle of health is out of balance?
Disease
Host
Chiropractic
Agent
Allopathic
Environment
Public Health
Study of the cause of disease
Etiology
Disease caused by infections of pathogenic microorganisms
Germ theory of disease
What are some factors that contribute to virulence?
Adhesion factors Biofilms Extracellular enzymes Toxins Antiphagocytic factors
Inability to make attachment proteins or adhesions renders microorganisms what?
Avirulent
Some bacterial pathogens attach to each other to form this
Biofilm
These are secreted by the pathogen to help maintain infection, invade, and avoid body defenses. Such as hyaluronidase and collagenase
Extracellular enzymes
Chemicals that harm tissues or trigger host immune responses that cause damage
Toxins
What are two types of toxins?
Exotoxins: cytotoxins, neurotoxins, enterotoxins
Endotoxins: lipid A
Protective molecules (antibodies) formed by host and may be administered artificially
Antitoxins
These prevent phagocytosis by the host’s phagocytic cells (such as bacterial capsule or leukocidins)
Antiphagocytic factors
What are the 5 stages of infectious disease?
Incubation period Prodromal period Illness Decline Convalescence
Between infection and first symptoms or signs
Incubation period
Short period of generalized, mild symptoms
Prodromal period
Most severe stage, signs/symptoms evident
Illness
Immune response/treatment vanquish pathogens, body slowly returns to normal
Decline
Patient recovers from illness, tissue repaired and returned to normal
Convalescence
What are some portals of exit?
Bodily secretions (earwax, tears, saliva) Blood Vaginal secretions or semen Breastmilk Bodily wastes (urine, sweat, feces)
What are the two most common portals of exit?
Sputum
Respiratory droplets
What are 5 groups of transmission?
Contact transmission Vehicle transmission Vector transmission Airborne Perinatal
What are three subtypes of contact transmission?
direct, indirect, or droplet
What are some common methods of vehicle transmission?
Waterborne, foodborne, fecal-oral, bodily fulids
What are some common methods of vector transmission?
Arachnid or insect, biological or mechanical vector
What is perinatal transmission?
Mom to baby
Disease in which symptoms develop rapidly and that runs its course quickly
Acute disease
Disease with usually mild symptoms that develop slowly and last a long time (more than 3 months)
Chronic disease
Disease with time course and symptoms between acute and chronic
Subacute disease
Disease without symptoms
Asymptomatic disease
Disease that appears a long time after infection
Latent disease
Disease transmitted from one host to another
Communicable disease
Communicable disease that is easily spread
Contagious disease
Disease arising from outside of hosts or from opportunistic pathogen
Noncommunicable disease
Infection confined to a small region of the body
Local infection
Widespread infection in many systems of the body; often travels through blood or lymph
Systemic infection
Infection that serves as a source of pathogens for infections at other sites in the body MRSA
Focal infection
Initial infection within a given patient
Primary infection
Infections that follow a primary infection; often by opportunistic pathogens
Secondary infection
Number of new cases of a disease in a given area during a given period of time
Incidence
Number of total cases of a disease in a given area during a given period of time
Prevalence
Disease that commonly occurs at regular intervals at a relatively stable incidence within a given population or geographical area
Endemic
Only a few scattered cases within a area or population
Sporadic
Occurs at a greater frequency than is usual for an area or population
Epidemic
An epidemic that occurs simultaneously on more than one continent
Pandemic
First case of the disease
Index case
Combination of tabulation of data and index case
Descriptive epidemiology
Combination of observational studies and experimental studies
Analytical epidemiology
Infections acquired in health-care settings (patients or employees)
Nosocomial infections
Pathogen acquired from the HC environment
Exogenous
Pathogen arises from normal microbiota due to factors in the HC setting
Endogenous
Results from modern medical procedures
Iatrogenic
What percentage of the USA gets nosocomial infections?
10%
What is the most effective way to reduce nosocomial infections
Handwashing
