infectious disease Flashcards
illnesses caused by the invasion of the human body by pathogen and microorganisms, producing harmful and potentially lethal consequenses
infectious diseases
organisms so small they are invisible to the naked eye, can only be seen with a microscope. can be pathogens or non-pathogens
microorganisms
the presence and multiplication within a host of another living organism with subsequent injury to the host
infection
the ability of an organism to enter, multiply, and survive in a host
infectivity
any organism capable of supporting the nutritional and physical growth requirements of another organism
host
the act of establishing a presence within a host
colonization
the disease producing potential of an invading organism
virulence
an organism so virulent that it is rarely found in the absence of disease
pathogen
a multitude of non-harmful bacteria inhabiting the internal and external exposed surfaces of the human body
microflora
free living organisms that obtain nutrition from dead or decaying organic materials in the environment
saprophytes
an organism which produces an infectious disease only when the health and immunity of the host have been severely compromised
opportunistic pathogen
the multitude of non-harmful bacteria inhabiting the internal and external exposed surfaces of the human body acquire survival needs from the host, but the host is not adversely affected.
commensalism
the skin, nose, pharynx, mouth, colon, rectum, vagina, distal urethra, and perineum are the locations of what?
normal flora
an interaction in which colonizing organism and host both derive benefits
mutualism
an interaction in which a colonizing organism benefits and the host sustains injury
parasitic
protein particles that lack any kind of demonstrable genetic material. aggregate in the brain and form plaques
prions
mutated forms of a normal host protein, may affect other normal proteins and alter them
prions
organism that combines the characteristics of viruses and bacteria: tiny gram negative bacteria that lives inside a host cell.
rickettsia
organism that combines the characteristics of viruses and bacteria: transmitted by insect vectors and cause diseases, rash, and small hemorrhages
rickettsia
organism that combines the characteristics of viruses and bacteria: primitive organism related to bacteria that lack many of the enzymes needed for metabolic process
chlamydia
organism that combines the characteristics of viruses and bacteria: causes a very common sexually transmitted infection which can lead to pelvic inflammatory disease
chlamydia
organism that combines the characteristics of viruses and bacteria: causes Q fever, and illness that presents with flu-like symptoms, and cause progress to become systemic affecting the heart, lungs, and GI
coxiella
organism that combines the characteristics of viruses and bacteria: commonly causes pneumonia, lacks a cell wall, therefore are not affected by antimicrobial drugs
mycoplasmas
free living eukaryotic saprophytes found in every habitat on heart
fungi
type of fungi: single celled organisms about the size of RBCs, produce asexually through a budding process
yeast
type of fungi: grow in long filaments called hyphae
molds
members of the animal kingdom that infect and cause disease in other animals
parasite
organisms including protozoa, helminths (worms), and arthropods
parasite
study of factors, events, and circumstances that influence the transmission of infectious disease in human population
epidemiology
number of new disease cases
incidence
number of active disease cases at any given time
prevalence
the host, object, location, or substance from which an infectious agent is acquired
source of infection
acquired from the host’s own microbial flora
endogenous
acquired from sources in the external environment
exogenous
transfer of microbes by physical contact
contact transmission
microbes are spread across a short distance (less than one meter) by small amounts of fluid (like sneezes or coughs)
droplet transmission
microbes are transmitted by air currents along long distances (more than one meter)
airborne transmission
animals, or biting arthropods, transmitting microbes to humans
vector born transmission
infection is transmitted by a contaminated source (food, water, etc.)
vehicle born transmission
location-based infections acquired during hospitalization, or from a health care facility
nosocomial infections
location-based infections acquired outside of health care settings
community acquired infections
the process by which a pathogen enters the body and gains access to susceptible tissue
portal of entry
any disruption in the integrity of the body’s surface barrier
penetration
pathogens transmitted directly from infected tissue or secretions to exposed, intact mucous membranes
direct contact
entry of infectious agent occuring through the oral cavity and GI tract
ingestion
entry of infectious agents through the respiratory tract
inhalation
the part of the body that is infected
site of infection
infection occurring in one body part
local infection
infection occurring in the whole body
systemic/generalized infection
the capability of a microorganism to cause disease
pathogenicity
the degree of pathogenicity of a pathogen
virulence
invasive qualities, toxic qualities, adherence to tissue, and ability to avoid host defences are the basis for what?
virulence
the collection of signs and symptoms expressed by the host during the diasease course
symptomatology
the process of a disease making its way though your system
disease course
phase of disease course: pathogen begins active replication without producing symptoms
incubation period
phase of disease course: initial appearance of symptoms
prodromal stage
phase of disease course: the host experiences maximum impact of the infectious process
acute stage
phase of disease course: containment of infection, progressive elimination of the pathogen, repair of damaged tissue, and resolution of associated symptoms
convalescent stage
phase of disease course: total elimination of pathogen from the body with no residual signs or symptoms
resolution stage
continuous signs and symptoms for months or years without a convalescent stage
chronic infection
progresses from infection to resolution without clinically apparent symptoms
subclinical/subacute illness
prodrodmal phase is gradual
insidious
abrupt onset of illness with little or no prodromal phase
fulminant
history, physical examination, culture, and serology are the basis of what?
diagnosis
antimicrobial agent, immunotherapy, and surgical intervention are the basis of what?
treatment
microscopic, single celled organisms that live in every conceivable environment
bacteria
how can bacteria cause disease?
producing toxins, invading tissue, or both
different types of bacteria within a species are referred to as what?
strains