exam 1 Flashcards
what leads to infection?
- poor hand hygiene
- not cleaning injuries
- sleep deprivation
- mask
- travel
- sanitation
- genetics
- war/conflict
what makes something infectious?
- has to be invasive
- pathogenic
- virulent-> scale of symptom severity
infection
the entry and development or multiplication of an infectious agent in the body of a man or animals
several levels of infection
- colonization
- subclinical or inapparent infection
- latent infection
- a manifestation of clinical infection
colonization
doesn’t have to be sick to be a carrier
subclinical
may have tingling
contamination
the presence of an infectious agent on a body surface, on or in clothes, bedding, toys, surgical instruments, or dressings, or other substances including water and food.
infestation
- the lodgement, development, and reproduction of arthropods on the surface of the body or in the clothing
- e.g. lice, itch mites.
public health
- when it works, nothing happens
- when it doesn’t work, public health is blamed
surveillance
what is the problem?
- identify a problem and surveillance system
risk factor identification
what is the cause?
- why is this a problem?
- what are they reading?
- who are they talking to?
intervention
what works?
- what worked in the past?
- how did people get vaccinated before?
- correlation vs causation
implementation
how do you do it?
- how are you going to do it?
- are you gonna make an event?
- what will the cost be
epidemiology
the study of distribution and determinants of health-related states and events in populations, and the application of this study to control health problems
- it is an integral component of public health
chain of infection in order
- pathogenic microorganisms
- reservoir
- means of escape
- mode of transmission
- means of entry
- host susceptibility
pathogenic microorganism
the infectious agent (microbe)
reservoir
people, water, animals, or where it lives
means of escape
how it gets out
(nose, mouth)
mode of transmission
- airborne
- waterborne
- insect borne
means of entry
how does it get into the next person
host susceptibility
- vaccination status
- age
- location
- genetics
what is the purposes in public health
- discover the agent
- determine the relative importance of illness, disabilities , and death
- identify those segments of the population that have the greatest risk from specific causes of illness health
- evaluate the effectiveness of health programs and services in improving population health
frequency
number of events
- cases
pattern
- occurrence of events by time, place, and person
host
- demographic characteristics
- biological characters
- socioeconomic characteristics
Agent
- biological agents
- physical agents
- chemical agents
- nutrient agents
- mechanical agents
- social agents
environment
- physical environment
- biological environment
- social environment
component causes
the individual factor that contributes to cause disease on a causal pie
sufficient cause
a complete causal pie
- a disease may have more than one sufficient cause
necessary cause
appears in every causal pie, because without it, the disease will not occur
evaluation
determining, as systematically and objectively as possible, the relevance, effectiveness, efficiency, and impact of activities with respect to established goals
linkages
bring many groups together to achieve the common goal
- how are you going to get young and old people on the same page
policy development
- uniquely qualified position to recommend appropriate interventions
- dealing with political views to get funding for campaigns and more
suspected
any febrile illness accompanied by rash
probable
- a case that meets the clinical case definition
- has non contributory or no serological or virological testing
- not epidemiologically linked to a confirmed case
confirmed
a case that is laboratory confirmed or that meets the clinical case definition
soft case definition
sensitive case definition is one that is “loose” in the hope of capturing most or all of the true cases
specific case definition
include only persons who were confirmed to have been infected with that organism
incidence
number of new cases in a given time period expressed as percent infected per year or number per person time of observation
prevalence
number of cases at a given time expressed as a percent at a given time
rate
- the number of cases divided by the size of the population per unit of time
- number of cases occurring during a specific period ( always dependent on the size of the population during that period)
epidemic or outbreak
disease occurrence among a population that is in excess of what is expected in a given time and place
cluster
group of cases is a specific time and place that might be more than expected (measles)
pandemic
a disease or condition that spreads across regions (has to spread across borders)
incubation period
contagious but doesn’t know it yet
latency
non- replicating
subclinical
carrier status
clinical
has recognizable symptoms and signs
infectivity
of how many people you can get sick
pathogenicity
causes disease
virulence
ability of a virus/bacteria to cause damage to host making them sick
carriers
person who mutated a gene that causes disease but has mild to no symptoms
common source outbreak
when a group of people are exposed to the same infectious agent/toxin
propagated epidemic
consistent and grows
what are the types of epidemic study?
- descriptive
- analytical
- experimental
descriptive
describe individuals who were infected (who, what, when, where, why)
analytical
- cause and effect
- how to improve past
- answers a question
morbidity
the number of people sick
mortality
number of people dead
contagious disease
one transmitted through contact
communicable disease
transmissible by direct contact with an affected individual or the individuals discharges or by indirect means (by vectors)
direct transmission
- person to person transmission of infectious agents through contact
indirect transmission
- include both vehicle borne and vector borne contact
- indirect transmission can come from fomites or from vectors
vector
any agent that carries and transmits an infectious pathogen into another living organism
- can be biological or mechanical
vector of infection
an insect or any living carrier that transports an infectious agent from an infected individual or its wastes to a susceptible individual or its food or immediate surroundings.
- both biological and mechanical transmissions are encountered
zoonosis
an infection that is transmissible under natural conditions form vertebrate animals to man
epizootic
an outbreak of disease in an animal population
enzootic
an endemic occurring in animals
emerging
newly identified & previously unknown infectious agents that cause public health problems either locally or internationally
re-emerging
infectious agents that have been known for some time, had fallen to such low levels that they were no longer considered public health problems & are now showing upward trends in incidence or prevalence worldwide
what factors contribute to emergence
- host
- human behavior
- environment
- social
poverty
malnutrition
- severe infectious disease cycle
what are the causes of antimicrobial drug resistance?
- wrong prescribing practices
- non-adherence by patients
- counterfeit drugs
- use of anti-infective drugs in animals & plants
consequences of antimicrobial drug resistance
- prolonged hospital admissions
- higher death rates from infections
- require more expensive, more toxic drugs
- higher cost health care
prokaryotic cell
- lack of nucleus and other membrane closed structures
- single celled
prokaryotic cell domains
- archea
- no disease causing organisms
- thermophiles
- extremophiles
- bacteria
eukaryotic cells
- contains a nucleus and other membrane bound structures
- plorgatnellemals , fungi, protists
prokaryotic cells
- relatively small (.5-2um in diameter)
- large surface volume (3:1 membrane:cytoplasm)
- metabolism will be on its membrane since there are no organelles
coccus (cocci)
sphere shaped
bacillus (bacilli)
rod shaped
Spirochete
tight spiral w/ flagella wrapped around it
- has corkscrew movements
vibrio
comma shaped
spirillum
looser spiral
pleomorphism
- stars
- rosetta
- squares
dipole
- 1-> 2
- diplo shaped
- diplococcus
- divided in one plane
tetrads
- 1->4
- strepto
- chains
- streptococcus
- divided into two planes
sarcinae
- 1->4
- staphylo
- clusters
- staphylococcus
- divided in three planes
bacillus
- 1->2
- divided in one plane end to end making chains
peptidoglycan
- peptide/sugars
- in all cell walls
- maintain shape
- prevents the cell from lysis
thick peptidoglycan includes what?
- lysine
- bridge
thin peptidoglycan includes what?
- no bridge
- DAP
how does water get through peptidoglycan?
osmosis
peptidoglycan components
- sugar backbone
- tetra-peptide cross-linkers
- pentaglycine bridge
- thick-GPB
-thin-GNB
gram negative cell walls outer membrane
- fluid mosaic model
- LPS components
- potent stimulator of fever (contains O antigen)
- phospholipid bilayer
gram negative cell walls peptidoglycan
- DAP-type
- thin
- no bridge
gram negative cell walls periplasmic space
- where toxins can be stored
- digestive enzymes
- protein pumps
- bacterial toxins
gram positive cell walls peptidoglycan (thick)
- lys-type
- has lipotechoic acid & techie acid
- fever to 100-102
- has periplasm (semisolid & helps distribute weight)
Acid fast cell walls
- 60% lipids
- has to be dissolved with acid
Prokaryotic plasma membrane
- selectively permeable
- passive diffusion
- osmosis
Aerobic
uses oxygen
anaerobic
uses something other than oxygen
facultative anaerobes
can switch between aerobic & anaerobic
micro aerophiles
- use oxygen 2-10% atmospheric water & packaging
desiccation
water
formation of endospores
- resistant to heat, desiccation, and chemicals
- special structures are problematic
- bacillus, clostridium can make endospores
organelles of eukaryotic cell
- nucleus
- mitochondria
- ER
- golgi
- vacuoles
-glycocalyx - cytoskeleton
cilia, flagella, & glycocalyx
- motility
- 9+2 paring
- slime layer
- capsule
fungi
thick inner layer
- chitin
- cellulose
thin outer layer
- mixed glycans
algae
- cellulose
- pectin
- mannans
- minerals
cell membrane
- has cholesterols
- phospholipid bilayer
- selectively permeable (osmosis & diffusion)
cilia
200 rpm
flagella
runs and tumbles (can generate straight or has to spin to change direction)
glycocalyx
tight or loose
tight glycocalyx
- dry proteins & sugars that lack waters
- “egg shell” fragile but protective
loose glycocalyx
- more wet
- causes sliding
- creates biofilms (like plaque)
what does the nucleus include?
- nuclear pore
- nuclear envelope
- nucleolus
- chromosomes
- histones
mechanical vectors
“Ubers” that transport parasites
hyperparatism
parasite that has a parasite
biological vectors
-organisms that transmits disease
accidental parasites
parasites that are parasitizing something other than their host
definitive host
host in which the parasite replicates
intermediate host
any other life cycle stage
- tend to vary different biologically
encystment
membranous incasing that protects the parasite
immunological challenges
changing outer layer coat makes it so that the immune system is confused
host cell invasion
evolved to get away from us
- can be in you for 25 years
nutritional deprivation
deprive host of nutritions ( bloating , hairloss)
direct trauma/ obstruction
hooks onto the internal tube of the body causing trauma by perforation. causes obstruction by stopping functions
- lay about 200,000 eggs/day
inflammatory/ immunological reactions
constantly causing inflammation/pain
mycology
study of fungi
thallus
body of fungus
mycelium
in the food source
hyphus
make up the thallus
ectoplasm
- rough/viscus cytoplasm
what happens when ectoplasm is lacking water?
it will create a protein called a cyst
what happens when ectoplasm has too much water?
it will become a trophozoite
- metabolically active
- direct
protozoa
unicellular, eukaryotic organisms
trypansoma
transferred by insect
mastigophoran
enlarges the heart
- infects humans
leishmania
causes immune response issues
ciliophora
most are harmless
apicomplex
- most medically important
- most complex
platyhelminths
-flatworms
- size (1mm-30mm)
- except tapeworms are 6-25ft
- no tubular digestive tract
- absorb nutrients through skin
- have both male and female parts
- flukes & tapeworms
nematodes
- heart worm
- size (1mm-2mm)
- has tubes (digestive tract)
- has males population and female population
- intestinal/ circulatory parasites
- parasitic adult/larvae forms
flukes
- class of parasitic flatworms
- tissue flukes
- blood flukes
- life cycle with multiple hosts
tapeworms
- class of parasitic flatworms
- scolex
- proglottids
- generalized life cycle involved intermediate and definitive hosts
arthropods as vectors
- arachnid
- insects
- crustaceans
virus
- can infect overtype of cell
- obligate intracellular parasites
- cannot multiply unless invade a specific host cell and instruct its genetic and metabolic machinery to make/ release new viruses
nucleic acids
- DNA or RNA
- known as the “core”
- found in the center
capsid
capsomeres
DNA
- includes double stranded and single stranded
double-stranded DNA
can be linear or circulate
(5’->3’ or 3’->5’)
single stranded DNA
- 5’ -> 3’= positive and can replicate
- 3’ -> 5’= negative and has to be degraded to go through replication
RNA
-more problematic
- includes mRNA, RNA, and retroviruses
what does naked mean?
no phospholipid bilayer
envelope meaning
phospholipid bilayer
- spikes
- 13 of 20 animal virus families
prions
- infectious proteins
- changes from alpha helices to beta pleated sheets
what can prions do?
prions can build up like plaque in the axon of a neuron, causing a blockage of signals (can cause many problems)
