Human Infectious Disease Exam Two Part One

achapss's version from 2017-03-24 12:13


Question Answer
Retrovirus single strand positive sense virus that starts as RNA that matches the mRNA of the host and converts to DNA to trick host into reproducing and then back to RNA utilizing a special enzyme
Positive Sense goes directly to translation has the matching sequence as the host's mRNA
Negative Sense has the opposite sequence to messenger RNA of the host and needs to be transcribed before translated to protein
Virionpackages of new viral genome, viral nucleic acids begin to synthesize building blocks for viruses, can have enzymes, capsids, spikes
What are the two options for a virus to escape once it has replicating within a host cell?1. bud off with envelope leaving host cell alive 2. if it doesn't have an envelope virions will build up and it will burst
cytopathic effectsvirus induced cell damage after virion release
syncytial30-40 multinucleated cells join together after virion release signaling near death
Persistent infectioncells are converted to virus factories continuously producing virions and hiding in the body, host will experience the virus at a random time
Provirusviral DNA can be incorporated into the hosts DNA
Latent Viruscan remain in the host cytoplasm waiting for an opportunity to break out and infect
Bacteriophagescan carry genes from one cell to another through horizontal gene transfer and alter bacteria to a different form
Primary Pathogenscan cause infection in anyone at any time
Opportunistic Pathogenscauses infection in those that are already immunocompromised and are probably already laying latent inside of host
What are the two main forms of protozoa?trophozoite - eating active living cells absorbing nutrients from host, cysts - dormant seed when nutrients are unavailable like endospores dehydrate everything but DNA
What are the four levels of microbe control?sterilization, disinfection, decontamination, antisepsis
sterilizationeliminates ALL microbes, uses autoclave and spore destroying chemicals
disinfectiondestroys vegetative cells but not spores, uses bleach, iodine, boiling
decontaminationreduces microbes on non living surfaces to safe levels, uses soap, detergent etc
antisepsisreduces microbes on living surfaces to safe levels using alcohol
-udeprefix meaning ability to kill
-sepsisgrowth of microbes in the blood
prophylaxispreventative treatment for at risk groups
Moist Heatphysical method for controlling microbes usually most efficient, utilizes steam and heat at a low temperature, the water allows for quick denaturation using hydrolysis
Dry Heatphysical method for controlling microbes at high temperatures over a long duration of time for eventual incineration of cells
TDT or TDPterminal death time or period, determined by infectious dose of a microbe, how long something needs to be cooked or exposed to heat to be safe
Cold Physical microbe controlslows down molecular movement and growth does not kill
ry Physical microbe controlsome microbes need a moist environment for survival and this will kill them
Radiation Physical Microbe controlkills absolutely all microbes through forming bonds of adjacent thiamines and cysteines deforming DNA
Bleach as a chemical mode of microbe controldenatures enzymes and kills everything
Alcohol as a chemical mode of microbe controldissolves membranes affecting the proteins in most bacteria, viruses, and fungi
What are some of the target areas of the actions of antibiotics?ribosomes to stop protein synthesis and avoid harming the host, cell wall and envelope to inhibit successful replication and division of bacteria messing with lipid membrane and peptidoglycan, inhibit folic acid synthesis of which ALL cells need but also harms host
Why aren't antibiotics successful against biofilms?they are unable to penetrate the biofilms and the bacteria are constantly changing and highly diverse
Protozoan and helminthic effective drugsneed to be a diverse array of them often attacking specific and multiple parts of the lifecycle, for protozoan infections antibacterial drugs can also be used that interfere with folic acid synthesis
What three mechanisms must an antiviral inhibit to be successful?docking and penetration of a virus into a host cell, transcription and translation once inside, prevention of maturity and assembly of viral particles utilizing protease inhibitors
Flemingdiscovery of first antibiotic penicillin
Waxmandiscovery of natural antibiotics through soil dwelling bacteria
Ehrlichdiscovery of synthetic antibiotics through using chemical dyes to cure syphillis
RNAimethod of combatting antibiotic resistance, short interfering RNA binds to mRNA and prevents proteins from being made can interfere with any RNA with little effect to human cells


Question Answer
Virulencethe relative severity of a pathogen dependent on its ability to damage the host and establish itself within the host
transmissibilitythe pathogens ability to damage the host and cross into new hosts dependent on its ability to survive outside the body and endure air and light
Portal of Entrylocation of entry for the pathogen including the skin, respiratory tract, urogenital, GI, blood
Transmission of GI dwelling pathogensfecal oral route
Transmission of blood dwelling pathogensmust travel with a vector or blood exchange
Transmission of respiratory dwelling pathogenstravel in the air mostly in airborne droplets from coughs and sneezes
Transmission of Reproductive system dwelling pathogensthe least hardy pathogens, rely on warm and moist direct transfer between hosts and have slow and usually infrequent transmission
What are the two modes of pathogen to host damage?direct damage - secretion of harmful chemicals and indirect damage - inducing host immune response
Endotoxinharmful chemicals of pathogen component of bacterial wall usually LPS triggering inflammation and fever
Exotoxinharmful chemicals of pathogen usually released into environment from inside
Neurotoxinnervous system
EnterotoxinGI tract
Localized infectionusually in one place like a cut
Systemic Infectionusually throughout the whole body like HIV
Acute infectionshort lived like the flu
Chronic Infectionfor life, comes in waves and episodes like HIV
Septicemiablood poisoning due to bacteria
Viremiaviruses in blood
What are the stages of infection?incubation - pathogen is inside but no symptoms, prodromal - symptoms are not severe and host can still function, period of invasion - rapid pathogen explosion and many symptoms, convalescent period - strength and health return
True Pathogenis an infectious agent that causes disease in virtually any susceptible host
Opportunistic Pathogenare potentially infectious agents that rarely cause disease in individuals with healthy immune systems
Endogenous Pathogenalready in the body circumstances change in the environment and result in activation and infection
Exogenous Pathogenpathogens acquired from the environment
Asymptomatic carriersdon't experience symptoms but still spread disease usually unknown to them, incubating and convalescent periods common ex: norovirus
Chronic Carriercontinued infection over time can spread to others
Passive Carriercarrier is uninfected but carries the pathogen and spreads continuously
Communicablemicrobe can be passed for person to person
non communicablemicrobe can not be passed form person to person usually microbiota
Direct Transmissionvertical or horizontal transmission requires some kind of human contact and exchange of bodily fluids in any way, bites, needles, etc
Indirect Transmissionno human contact usually from fomites or vectors some kind of pathogenic reservoir
Vertical Transmissiondirect transmission of disease between those of the same species from parent to child
Horizontal Transmissiontransmission of disease between those of the same species that do not have a parent child relationship