Flashcards in Infection, Infectious Diseases, And Epidemiology Deck (99):
What are the normal microorganisms found in our body that do not cause disease called?
Normal flora or indigenous microbiota
What type of microbiota in the body remain their for a person's entire life?
What type of microbiota remain in the body for a limited amount of time before disappearing?
What locations in the body are axenic?
Alveoli of lungs, CNS, circulatory system, upper urogenital regions, uterus
What does axenic mean?
Sites that are free of any microbes that are never colonized by flora
When does acquisition of normal microbiota occur?
Shortly after birth
What are opportunistic pathogens?
Normal microbiota that can cause disease under certain circumstances
What are the certain circumstances that could trigger normal microbiota to cause disease?
Introduction of normal microbiota into unusual site in the body, immune suppression, changes in the normal microbiota
What are the three types of potential reservoirs of infection for pathogens to live for protection?
Animal, human carriers, nonliving reservoirs
What is a reservoir of infection?
A location where a pathogen is likely to be found to live before they infect a new host
What are zoonoses?
Diseases naturally spread from animal host to humans
How can we acquire zoonoses?
Direct contact with animal or its waste, eating animals, bloodsucking arthropods
Who is usually considered to be a "dead-end host" and why?
Humans are more likely to get diseases from animals and the reverse is very unlikely
What is the reservoir for malaria?
What is the reservoir for toxoplasmosis?
What is the reservoir for anthrax?
What is the reservoir for the bubonic plague?
What is the reservoir for Lyme disease?
What is the reservoir for rabies?
Multiple but #1 involved with humans is bats
What is the reservoir for yellow fever?
What strategy is used to separate ill persons who have a communicable disease?
What strategy is used to separate and restrict well persons who may have been exposed to a communicable disease?
How do microbes usually get to locations of nonliving reservoirs?
Contamination by feces or urine
Soil, food, and water are examples of what kind of reservoir?
What is contamination?
The mere presence of microbes in or on the body
What is actual infection?
When an organism becomes established in the body that may or may not result in disease
What are the three main pathways used by pathogens to enter the body?
Skin, mucous membranes, placenta
What is the term for a route that isn't technically a portal of entry but a way to circumvent the usual portals of entry?
What are the portal entries of the skin?
1 openings or cuts
2 hair follicles or sweat glands
3 things that can actually burrow their way into the skin
What must a pathogen be able to withstand when using the GI tract as route of entry?
Must survive the acidic pH of the stomach
What is the most common route of entry for pathogens?
Respiratory tract (nose, mouth, and eyes)
How may pathogens infect a fetus?
By crossing the placenta
What type of protozoan can cross the placenta?
Toxoplasma gondii (toxoplasmosis in humans)
What types of bacteria are known to be able to cross the placenta to harm the fetus?
Treponema pallidum (syphilis in humans) and listeria monocytogenes (listeriosis in humans)
What DNA viruses are known to be able to cross the placenta to harm a fetus?
Cytomegalovirus (asymptomatic in adults), parvovirus B19 (erythema infectiosum)
What RNA viruses are known to cross the placenta to harm a fetus?
Lentivirus (HIV AIDS) and rubivirus (German measles)
What is the difference between infection and disease?
Disease is technically the result of the infection if it alters normal body functions (also known as morbidity)
What is pathogenicity?
Ability of a microorganism to CAUSE a disease
What is virulence?
Degree of pathogenicity and how easy it is for the organism to cause disease
What is antigenicity?
The ability of a substance to stimulate the production of antibodies or cell-mediated immune responses
Do pathogenicity and virulence refer to the severity of the disease?
No (example: you can be extremely virulent but only cause a minor condition)
Which is subjective: signs of symptoms?
Which is objective: signs or symptoms?
What is a group of symptoms and signs that characterize a disease or abnormal condition?
What are subjective characteristics of disease felt by only the patient?
What are objective manifestations of disease observed or measured by others?
Definition of -emia
Pertaining to blood
Definition of -gen or gen-
Give rise to
Definition of idio-
Definition of septi-
Rotting (refers to presence of pathogens)
Definition of -osis
Definition of terato-
Definition of tox-
What is necessary for infectious agents to establish colonies after entering the body?
They must adhere to cells
What are extracellular enzymes?
Those secreted by the pathogen
What is the function of extracellular enzymes?
Helps pathogen maintain, invade, and avoid the body's defenses
Cytotoxins, neurotoxins, and enterotoxins are examples of what kind of toxins?
Lipid A is an example of what kind of toxin?
What is the function of toxins of infectious agents?
Harm tissues or trigger host immune responses that cause damage
What is the function of leukocidins?
Prevents the white blood cells from being able to digest the infectious agent and can even destroy them
What are the stages of infectious disease in order?
Incubation period, prodromal period, illness, decline, convalescence
When is the incubation period of infectious disease?
Between infection and first symptoms or signs
What is the prodromal period of infectious disease?
Short period of generalized, mild symptoms
What is the most serious stage of infectious disease?
What is the illness stage of infectious disease?
When signs and symptoms are most evident
What is the decline stage of infectious disease?
Immune response/treatment vanquish pathogens, body slowly returns to normal
What is the convalescence stage of infectious disease?
Patient recovers from illness tissues repaired and returned to normal
How can pathogens leave the host?
Bodily secretions, blood, vaginal secretions or semen, breast milk, bodily wastes
What are the five groups of transmission of infectious agents?
Contact, vehicle, vector, airborne, and perinatal
What is the term for an inanimate object involved in indirect transmission of infectious agents?
What mode of transmission of infectious agents involves a non-living middle man?
Which mode of transmission of infectious agents involves a living middle man?
Vector transmission (can be mechanical or biological)
Waterborne, foodborne, or fecal-oral body fluids represent what kind of mode of transmission for infectious agents?
What kind of mode of transmission of infectious agents by an arachnid or insect being a middle man?
Mom to baby transmission is what kind?
What kind of vector in transmission only carries the pathogen?
What kind of vector in transmission serves as the host for the pathogen, as well?
Ticks and mites are what kind of arthropod?
Fleas and lice are what kind of arthropods?
How many pairs of legs do arthropods have?
How many pairs of legs do insects have?
Insects (along with three body regions)
What is the most important arachnid vector?
Are spiders arachnid vectors?
No; they do not transmit pathogens
What is the most important and most common insect vector?
Mosquitos (most important vector overall, too)
What is the term for the number of new cases of a disease in a given area during a given period of time?
What is the term for the number of total cases of a disease in a given area during a given period of time?
What is the term for a disease that normally occurs at regular intervals with stable incidence within a given population or geographical area?
What is the term for only a few scattered cases within an area of population?
What is the term for when a disease occurs at a greater frequency than is usual for an area or population?
What is the term for an epidemic that occurs simultaneously on more than one continent?
What is an index case?
The first victim/case of a particular outbreak of an infectious disease
What is involved with a careful tabulation of data concerning a disease?
Recording of location and time of the cases of disease along with patient information
What is a nosocomial infection?
An infection acquired in health-care settings (patients or employees)
What are the three subcategories of nosocomial infections?
Exogenous, endogenous, iatrogenic
What kind of nosocomial infection results from a modern medical procedure?
What kind of nosocomial infection involves a pathogen arising from normal microbiota due to factors in the health care setting?
What kind of nosocomial infection involves the pathogen being acquired from the health care environment?
What is the most effective way to reduce nosocomial infections?