Infectious Disease Flashcards
Microorganisms
Organisms so small they are invisible to the naked eye and can only be seen with a microscope.
All Microbes are microorganisms, but not all microorganisms are _____
Microbes
Infection
The presence and multiplication within a host of another living organism with subsequent injury to the host
Infectivity
The ability of an organism to enter, multiply, and survive in a host
Host
Any organism capable of supporting the nutritional and physical growth requirements of another organism.
Colonization
The act of establishing a presence within a host
Virulence
The disease producing potential of an invading organism.
Pathogen
An organism so virulent that it is rarely found in the absence of disease
Microflora
A multitude of non-harmful bacteria inhabiting the internal and external exposed surfaces of the human body
Saprophytes
Free living organisms that obtain nutrition from dead or decaying organic materials in the enviornment
Opportunistic Pathogen
An organism which produces an infectiois disease only when the health and immunity of the host have been severly compromised
Commensalism
Non-harmful bacteria inhabitying the internal and external exposed surfaces of the human bodyu (microflora) acquire survival needs from yjehost but the host is not adversely affected by this relationship.
Locations of normal flora in the human body are
Skin Nose/Pharynx Mouth Colon/Rectum Vagina/Distal Urethra/Perineum
Mutualism
An interaction in which colonizing organism and host both derive benefits eg. SSome bacteria that live in the intestines and feed off of undigested foood also produce vitamins beneficial to humans
Parasitic
An interaction in which a colonizing organism benefits and the host sustains injury
Prions
Protein particles that lack any kind of demonstrable genetic material. They are mutated forms of a normal host protein. Prions may affect other normal proteins and alter them.
Where are prions found in the body
Aggregate in the brain and form plaques
Prions have been identified in a number of incurable and transmissible degenerative neurological diseases
Creutzfeldt jakob disease
kuru
mad cow disease
Rickettsia
Tiny gram negative bacteria that live inside a host cell (obligate intracellular parasites)
How are Rickettsia transmitted and manifested in the body
insect vectors and cause diseases like typhus, rocky mountain spotted fever. They cause a typical rash, and cause small hemorrhages
Chlamydia
A primitive organism related to bacteria that lack many of the enzymes needed for metabolic processes
Coxiella
Causes Q fever and illness that presents with flu-like symptoms, and cause progress to becomr systemic affecting the heart, lungs and GI
Mycoplasmas
Commonly cause pneumonia.. These organisms lack a cell wall therefore they are not affected by antimicrobial drugs
Fungi
Free living eukaryotic saprophytes (lives on dead or decaying organic matter) found in every habitat on earth
Two types of fungi
Yeast and molds
Yeast
Single celled organisms about the size of RBCs. They reproduce asexually through a budding process
Molds
grow in long filaments called hyphae
Parasites
Infect and cause disease in other animals. They include protozoa- unicellular eukaroytes that may reproduce sexually or asexually. Most are saprophytes. Some are pathogenic to humans ex malaria, amoebic dysentery, giardiasis, trichomonas vaginitis
Helminths
aka worms- roundworms, tapeworms, flukes. They reproduce sexually
Arthropods
Tics, mosquitoes, lice, fleas, mites
Epidemiology
the study of factors, events, and circumstances that influence the transmission of infectious disease in human populations
Source of infection
Endogenous (acquired from the hosts own microbial flora), exogenous (Acquired from sources in the external enviornment), source of infection can be another person (transmission of illness from mother to child during gestation), contact transmission occurs from transfer of microbes by physical contact,
