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206 Cards in this Set
- Front
- Back
pathogen?
|
a organism capable of causing disease
|
|
symbiosis
sym=? |
a relationsip that two organisms living together have
-normal flora |
|
mutualism
|
both members benefit
-Termites& the bacteria that’s in their gut that digest the wood |
|
parasitism
|
one member benfits the other is harmed
|
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commensalism
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somewhere in between
-normal flora on your skin |
|
contamination
|
microorganisms are present
|
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infection
|
multiplication of any parasitic organism either in or on the host body
-bacteria, fungi, etc |
|
disease
|
any disturbance in the state of health where in the body cannot perform its normal functions
|
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pathogenicity
|
the degree to which an organism can cause disease
-mycobacterium TB -staphylococcus epidermis-the natural bacteria on your skin |
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virulence
|
refers to the intensity of the disease produced by the organism
|
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animal passage
|
often diseases become more virulent as they pass through individuals
ex: influeza-as it's gone through person to person it gained virulence..elderly and children can die |
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attenuation
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the weakening of the disease producing ability of a pathogen
-can be used for vaccines bc it's a weakened form |
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how many cells in the human body?
how many x more bacteria? |
10trill.
10x |
|
normal microbiota?aka?
2 types? |
those MOs that live in the body but do not cause disease (aka normal flora)
resident and transient |
|
resident microbiota?
|
the MO that are always present on the human body
|
|
transient microbiota?
|
the MO that may be present at any given time if the conditions are right
|
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what is always in your gut unless you've been taking alot of antibiotic?
|
ecoli
|
|
opportunists?
examples? |
normally don't cause disease, but if the conditions are right they can produce disease
-ex: reak havoc on patients w/ aids, intro to different body site: ecoli going from intestinal tract to urethra-most common pathogen for uti's |
|
under what 3 conditions can opportunists produce disease?
|
1. failure of the immune system
2. intro to a different body site 3. disturbances of the normal balances of MO |
|
10 classes of human disease?
|
inherited, congenital, degenerative, nutritional, endocrine, mental, immunological, neoplastic, iatrogenic, idiopathic
|
|
define&ex:
inherited? |
caused by mistakes in the DNA that are inherited from the parents
-sickle cell anemia |
|
congenital?
|
structural and functional diseases that are present at birth, caused by drugs, radiation, and certain infections
-TORCH |
|
degenerative
|
develop in the body as a part of the aging process or as a body system begins to degenerate
-endocarditis |
|
nutritional
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arise form a lack of a specific nutrient
-diptheria-if a person lacks iron, they're more susceptible |
|
endocrine
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excess or deficiency in any hormone
-juvenile onset diabetes could be caused by mumps |
|
mental
|
damage to either brain tissue or brain function
-syphilis or mad cow disease |
|
immunological
-immunodeficiency? -autoimmune? |
diseases of the immune system
-HIV/aids(immunodeficiency), lupis(autoimmune) -not enough immunity -the immune system attacks itself |
|
neoplastic
|
abnormal cell growth
-cancer, HPV |
|
Iatrogenic
|
caused by medical procedures
-nosocomial infections |
|
Idiopathic
|
diseases of unknown origin
-possibly alzthimers |
|
what are the 2 types of diseases? define
|
communicable=those diseases which can be spread from one person to another
noncommunicable=those diseases which cannot be spread |
|
examples of communicable
|
flu, cold, TB
|
|
examples of noncommunicable
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infections caused by a persons normal flora(uti)
infections caused by environmental exposure(from cuts and abrasions from an accident) poisoning caused by the ingestion of a preformation(botulism-food poisoning) |
|
virulence factors
-an ex? |
special structures or physiological characteristics that help MO's cause disease
-a capsule |
|
adhesions?
most adhesions are ? usually found where? most adhesions are also ___ factors? |
proteins or glycoproteins that give the bacteria the ability to "stick" to the cells of the body
-cell type specific -as a part of the attachment pili(fimbrea) or capsules -antiphagocytic |
|
colonization?
-what must happen w/ the pathogens? |
growth of the MO on an epithelial surface or mucous membrane
-they must survive and reproduce despite host defense mechanisms |
|
invasiveness?
some bacteria release __ to help them invade? |
the ability to invade and grown in host tissues
-digestive enzymes |
|
examples of some invasive virulence factors
hyaluronidase?ex? |
an enzyme that digests hyaluronic acid which is the "glue" that holds certain types of cells together
-streptococcus pyogenes(flesh-eating bacteria) |
|
Coagulase?ex?
|
an enzyme that accelerates the coagulation of blood
-staphylococcus aureus |
|
what does staphylococcus aureus do?
|
it ties itself up with fibrin, and protects the staph by using something from the body so the body's organisms cannot get to it. makes it more virulent
|
|
streptokinase?
|
an enzyme that breaks down the blood clot
|
|
what do intracellular MOs do?
|
they get through the body by taking a free ride on the WBC's it makes these organisms more virulent
|
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what are 2 ex of intracellular MOs? they do what?
|
mycobacterium TB and neisseria gonorrhea
-can survive inside phagocytic cells to gain access to the deeper parts of the body |
|
what are hemolysins?
2 types? |
exotoxins that lyse RBCs
-alpha and beta |
|
what do alpha hemolysins do?
|
lyse RBCs and partially break down Hb resulting in a greenish ring around the bacterial colonies(when grown on blood agar)
|
|
what do beta hemolysins do?
|
lyse RBCs and completely break down the Hb
|
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what does the exotoxin, leukocidin do?
|
destroy neutrophils and macrophages
|
|
what does the exotoxin, leukostatin do?
|
interferes with the ability of phagocytes to ingest bacteria
-all toxemia |
|
what are the 2 kinds of bacterial toxins?
|
exotoxins and endotoxins
|
|
what are exotoxins?where are they found?
|
toxins that are released from the bacterial cell into the host while the bacteria is still alive
-cell wall |
|
what are endotoxins?
|
part of the gram negative cell wall that is released when the bacteria die-LPS(lipopolysaccharide)
-ppl can get worse on antibiotics when they have a gram - cell wall |
|
intoxication?ex?
|
ingestion of a toxin
-clostridium botulinium-botulism(food poisoning) |
|
toxin tissue specificity
what are 2 ex of toxins that are tissue specific? |
neurotoxins-attack nervous sytem
enterotoxins-attack intestinal tract |
|
what are toxoids?ex?
|
modified toxins that are no longer harmful, and can be used as vaccines
-tetanis vaccine |
|
how do viruses cause disease?
|
viruses can cause disease ONLY after they attach and penetrate the host cell
|
|
Cytopathic effects?define
|
(CPE) are the observable changes that occur in a cell following virus infection
|
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list the 4 types of viral infections?
|
productive, abortive, latent, persistant
|
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what happens in a productive viral infection?
|
the virus can attach, penetrate, and replicate
|
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what happens in an abortive viral infection?
|
the virus can attach and penetrat, but not all of the viral genes are produced, so the virus cannot replicate
|
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what happens in a latent viral infection?ex?
|
after the initial infection the virus lays "dormant" in a specific cell type(usually a nerve cell) and can reactivate later in life(chicken pox- shingles)
|
|
what happens in a persistant viral infection?ex?
|
following infection the virally infected tissue continues to make infectious particles for a long period of time (Hepatitis B)
|
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what is a sign?
|
a characteristic of a specific disease that can be observed by examining the patient (rash, runny nose, fever, etc.)
|
|
what is a symptom?
|
are characteristics of disease that can only be felt by the patient (pain, nausea, sore throat)
|
|
whats a syndrome? most infections cause a syndrome known as the ___ ___?
|
a combination of signs and symptoms that occur together and are indicative of a particular disorder
inflammatory response |
|
define sequelae?ex?
|
the after effects of a disease
-polio--paralysis -strep throat--rhematic fever can occur |
|
acute disease?ex?
|
disease in which symptoms develop rapidly and that runs its course quickly
-cold, flu, measles, chicken pox |
|
chronic disease?ex?
|
disease in which symptoms develop slowly and disease is slow to disappear
-TB |
|
subacute disease?ex?
|
disease with symptoms intermediate between acute and chronic
-gingivitis or gum diseaes |
|
latent disease?ex?
|
disease in which symtoms appear and/or reappear long after infection
-shingles |
|
local infection?ex?
|
infection confined to a small region of the body, such as a boil or bladder infection
-bladder infection |
|
focal infection?ex?
|
infection in a confined region from which pathogens travel to other regions of the body, such as an absessed tooth or infected sinuses
-sinus infection |
|
systemic infection?ex?
|
infection in which the pathogen is spread throughout the body, often traveling through blood or lymph
-pneumonia |
|
septicemia?
|
presence and multiplication of pathogens in blood
|
|
bacterimia?
|
-presence and multiplication of bacteria in blood
|
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viremia?
|
presence but not multiplication of viruses in blood
|
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toxemia?
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presence of toxins in blood
|
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sapremia?ex?
|
presence of metabolic products of saprophytes in blood
-can be fungi; a person can be drunk w/out drinking anything by having a specific strand of candida(yeast) |
|
primary infection?ex?
|
infection in a previously healthy person
-strep, TB, anything |
|
secondary infection?ex?
|
infection that immediately follows a primary infection
-septicemia could come after pnemonia |
|
superinfection?ex?
|
secondary infection that is usually caused by an agent resistant to the treatment for the primary infection
-yeast infection or clostridium dificil |
|
mixed infection?ex?
|
infection caused by two or more pathogens
-much more difficult to treat bc of different susceptibility levels |
|
inapparent infection?ex?
|
infection that fails to produce full set of signs and symptoms
-hepetitis B |
|
what are the 5 phases of infectious disease in order?
|
incubation, prodromal, illness, decline, convalescence
|
|
incubation phase?
leprosy? |
the stage during which the person does not know they are infected, however, they are usually contagious
-1 ceell divides every 12 days |
|
prodromal phase?
|
you know you don't feel well, but you are not quite sure what you feel, still infectious
|
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illness phase?
|
the period during which you have the specific signs and symptoms of the infectious disease that you are growing
-the battle between the immune system and the MO is at its height |
|
decline phase?
|
the immune system w/o treatment regimen begin to win the battle
|
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convalescence period?
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the recovery period, the body must regain the strength that it used while fighting the disease
|
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things that reduce infectious disease?
|
vaccines, antibiotics, antiseptics, clean h2o, and sanitation, increase in med technology
|
|
besides resistance and ppl not getting vaccinated, things that cause disease is?
|
HIV
|
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define epidemiology?
|
the study of factors and mechanisms involved in the spread of disease
-who, where, when, how |
|
incidence vs. prevalence
ex? |
-# of new cases-total # of people infected
|
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mobidity vs. mortality
ex? |
sickness-death
|
|
endemic?ex?
|
constant level of infection
-colds |
|
epidemic?ex?
|
sudden increase in the number of cases
-flu |
|
pandemic?ex?
|
world-wide epidemic
-HIV&aids. health officials are afraid of bird flu coming into contact w/ human flu virus& is transmitted by respiratory; makes lungs the consistancy of pudding |
|
sporadic?ex?
|
random and unpredictable
-plague |
|
St Louis encephalitis?
|
rise in cases due to nonimmune bird population and large mosquito population
|
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what are 3 reservoirs of infection?
|
human, animal, nonliving reservoirs
|
|
human reservoir of infection?ex?
|
carriers, ppl who are infected but do not have observable signs or symptoms of disease
-TB, meningitis, strep throat |
|
animal reservoir of infection?ex?
|
about 150 infectious agents can infect both man and animals
-zoonosus-the agents that can infect both man&animals;rabies |
|
nonliving reservoirs of infection?ex?
|
fomites(inanimate object), fecal material, other non-living stuff
-fomites(doorknobs, phones, etc) |
|
what are the 3 modes of transmission?
|
contact, vehicle transmission, and vector transmission
|
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what are 3 examples for the contact mode of transmission?
|
direct contact(person to person), indirect contact(fomites), droplets(cough, sneeze, etc)
|
|
what are 3 example for the vehicle transmission?
|
waterborne(drinking water), airborne-on dust particles(may overlap contact), food borne
|
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what are 2 ex. of vector transmission?
|
mechanical(the feet and mouth parts of house flies), biological(usually by biting of fleas(plague) and ticks(limes disease))
|
|
Special Problems:
carriers don't know what? STDs-most STDs for women don't what? |
-they are infected
-have signs or symptoms |
|
many diseases lie ___ for years and then reemerge to kill many ppl.
|
dormant
|
|
ex. of disease cycle?
|
Bubonic plague
-killed 200,000ppl in 4m b4 traveling to Europe&China -caused by Yersinia pestis(rodent population) -for about 500 yrs it was gone -in 1346 it resurfaced and killed 1/3 of the pop. of Europe -17th century, England -18th century, France -20th century, India |
|
the proportion of individuals in a group of ppl that is immune to a disease?
|
herd immunity
|
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diseases have a hard time propagating if most of the population is ___?
this is why a small # of ppl in the USA can avoid what? |
immune
vaccination |
|
what are 4 ways of control of disease transmission?
|
isolation, quarantine, immunization, vector control
|
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what is isolation?
|
the patient is separated from the general pop.(usually in the hospital
|
|
define quarantine?
|
the separation of "healthy" ppl from the pop. following exposure to an infectious agent
-prevents the spread of disease during its incubation period |
|
define immunization?
|
creating "herd immunity" in a pop. by vaccinating against a specific agent
|
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define vector control?
|
killing the organisms that carry the disease, mosquito control is a good ex.
|
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what are the 2 public health organizations?
|
Centers for Disease Control(CDC)
World Health Organization(WHO) |
|
what is a notifiable disease?
|
diseases which must be reported to the CDC by the person diagnosing the condition
|
|
nosos=?
komeo=? |
=disease
=to take care of |
|
how many ppl aquire nosocomial(hospital acquired infections) each year?
how many of them are fatal? |
2million
20,000 |
|
what are the top 3 sites of nosocomial infections? ex of each?
|
urinary tract(uti's-common bc of catheders; kidney infection)
respiratory tract(pneumonia) surgical wounds |
|
what are the top 3 MOs seen in nosocomials?which is the most common?
|
e. coli, staphylococcus aureaus, and streptococcus
|
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what 2 things does staphylococcus aureaus include?
|
MRSA, VRSA
|
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what does streptococcus include?
|
enterococcus
|
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when&why were the universal precautions "guidelines" created?
applies to ___ ____? |
1988 bc of concern that the AIDS virus would be transmitted in the health care setting
-all patients |
|
Some Important Universal Precautions and Recommendations from the CDC:
|
1. Wear gloves&gowns if soiling of hand, exposed skin, or clothing wiht blood or body fluids is a likely
2. Wear masks&protective eywear or chin-legnth plastic facesheilds whenever splashing of blood or body fluid is likely; a mask alone is not sufficient 3.Wash hands b4 and after patient contact, and after removal of gloves. Change gloves b4 ea. patient 4. Use disposable mouthpiece/airway for CPR 5.Discard contaminated needles and other sharp items immediatly into special disposal. Needles must not be bent, clipped or recapped 6. Clean spills of blood or contaminated fluids by 1) putting on gloves&any other barriers needed 2)wiping up with disposable towels 3)washing w/ soap&water 4)disinfecting with a 1:10 solution of household bleach&water Allow it to stand on surface for at lease 10min. Bleach solution should not have been prepared more than 24hrs beforehand |
|
skin is a ____ defense, is a physical barrier that secretes ___ chemicals.
|
nonspecific
antimicrobial |
|
Skin as a defense against MO:
-__&___ secretions -___ ___ that prevents water-soluble substances from entering the body -what is sebum? |
acidic&salty
-waterproofing keratin -an oily substance thta provides nutrients for normal flora& keeps skin at an acidic pH that discourages pathogen growth |
|
bacterial skin diseases generally require what?
|
a break in the skin barrier
|
|
staphylococcal infections: what is the form that virtually all ppl are colonized by within 24hrs after birth?
|
staph aureus
|
|
staphylococcus aureua dn other species (general info):
grows how? common where? halotolerant? resistant to many ___ virulence factors(skin) -3 factors? spread how? diagnosis? treatment? prevention |
-grows in clumps or clusters
-common flora of skin and hair, grows in sweat(halotolerant-salt tolerant) -many antibiotics -Protein A-antiphagocytic(meaning it keeps it from being phagocytized) -coagulase-it will utilize the fibrin in the clot to protect itself -exfoliation -spread by direct contact -culture -some penicillins and vancomycin; some very resistant -wash hands |
|
staph abscesses are usually what?
-prevents ____ -limits ___ ___ |
encapsulated
-septicemia -antibiotic access |
|
what is septicemia?
|
its a blood infection that multiplies
|
|
with staph abscesses what is sometimes necessary?
|
lancingf
|
|
staph infections are what?
|
highly contagious esp. in older patients
|
|
scalded skin syndrome is only occurs by Staph. aureus is the exotoxin ____ is produced.
__#? forms of the toxin. found in 2 different places?either can cause scalded skin syndrome |
exfoliation
-2 -chromosome, plasmid |
|
what are 2 rare occurences w/ scalded skin syndrome?
how many strains of this are there?antibodies can only protect when? |
-septicemia&death
-2 -only if it occurs by the same strain |
|
how are streptococcal infections spread?
|
direct contact&aerosols
|
|
the rapid test for streptococcal infections is only about __% specific..so __% goes undiagnosed
|
90, 10
|
|
how many different types of toxin have been isolated in cases of scarlet fever? Each can cause it __ bc each is a good antigent.
|
3
|
|
People w/ scarlet fever can be ___ carriers, and ___ are a source of transmission.
|
asymptotic; fomites
|
|
Before antibiotics, Erysipelas occured often when?__ was high. Is it common today?
|
after wounds and surgery; mortality
-no |
|
infection for erysipelas occurs where and spreads along what?
|
at the sight on injury; along lymphatic lines
|
|
what does the disease erysipelas tend to do? why?
|
reoccur, no good protective immunity
|
|
hemolytic streptococci does what?
|
breaks down blood
|
|
impetigo is a highly contagious form of what?
-it travels rapidly on ___ -occurs commonly in what age groups? -rarely__, but can cause__ -common in what school sport? |
pyoderma
-fomites -college kids and down -scars; loss of pigment -wrestling |
|
wat is acne?
wat is the single most effective treatment for it? |
infection of the sebaceous glands
-frequent skin cleansing |
|
scarring can persist in acne if ___ form from repeated infection
|
-granulomas
|
|
what are side effects of acutane?
-makes ur body think you're overdosing on __ |
depression, severe birth defects, liver damage
-vitamin A |
|
burn infections can be caused by nosocomial infections through ___ and ___.
|
common water and plant bacteria
|
|
You need really good ____ tests for burn infections. ___antibiotics are used.
|
susceptibility
-polymyxins |
|
2 types of bacteria can cause problems in burn patients?
|
serratia and providencia
|
|
what is an eschar?
|
a scab that forms over a burn
|
|
bacteria growing under the eschar are the problem, they can cause a local infection easily reach the blood and cause a life threatening ___.
|
septicemia
|
|
delivering antibiotics to burn infections is difficult bc there is no ___ of the eschar.
|
vascularization
|
|
____ of the wound in a burn patient allow antibiotics to prevent infection.
|
debridment
|
|
what are 3 reasons why burn patients are difficult to treat?
|
-they dont eat well
-they have electrolyte imbalances -they have no skin |
|
diagnosis for burn patients is___.
what are 2 signs of a pseudomonas infection. |
greenish discoloration or grape-like odor
|
|
gas gangrene has ___ ___
|
obligate anaerobes
|
|
spores in gas gangrene do what?they are___.
|
germinate and grow, causing extensive damage; resistant
|
|
exotoxins and enzymes such as ___,__,and___ do what 2 things?
|
collangenases, proteases, and lipases; kill other host cells and extent the anaerobic environment
|
|
Gas gangrene occurs within __-__hrs after injury.
|
12-48
|
|
what does gas gangrene look like under a scope?
|
box-car, large rods
|
|
Rubella(german measles) is infectious __days prior to rash, and then for __more days
__-__%carrier rate |
5;10
25-50% |
|
when would congenital rubella syndrome be caused in the pregnancy? how? what happens to the baby?
|
-1st 9 weeks of pregnancy
-happens if mother has had contact w/ measles in the first 9weeks&isn't immune -often child born blind, deaf, or stillborn |
|
rubella is contagious is almost all what?
|
body fluids
|
|
very low incidence of rubella in the USA since the development of the__ vaccine in the late ___. __shots are recommended
|
MMRV; 1960s; booster
|
|
what is a titer?
|
a titer checks to see wat your antibody level against that disease is--if you're sill immune
|
|
the measles virus gains entry through 3 places?
|
nose, mouth, or eyes
|
|
symptoms for measles appear within __-__days
it's most infectious when? |
9-21
-during prodrome stage |
|
what is sequelae?when does it occur?
|
subacute sclerosing panencephalitis(SSPE)
-occurs 6-8yrs after infection by measles, usually in children who had it b4 age 3(lays dormant for those yrs) -nearly 100%fatal -due to the persistance of measles in brain tissue and causes death to nerve cells |
|
how does the varicella-zoster virus(causing chicken pox or shingles) enter the body?
|
via upper repiratory&eyes
|
|
how does the this virus work in spreading throughout body?
|
replicates at the site of entry and then enters the blood stream, release of these viruses causes fever and malaise
|
|
when do lesions for chicken pox normally appear?children are normally infectious __hrs before skin lesions appear.
|
14-16 days after exposure
-48 |
|
lesions appear for __-__days in cycles that coincide w/ __ __
|
2-4, virus replication
|
|
usually though of as a mild disease of childhood, but it can be fatal if the virus invades the __ extensively..called what?it can happen in adults!
|
lungs; chicken pox pneumonia
|
|
varicella-zoster is a herpes virus it can lie dormant in __ __-dorsal root ganglion
|
nerve cells
|
|
recurrence of zoster provides a ___ for immunity
|
booster
|
|
shingles are __ viruses reside in the __&__.
|
latent; cranium, spine
|
|
reactivated, the viruses spread from the __ along the __
|
ganglion; pathway of the associated nerve
|
|
the latent virus is activated when cell mediated immunity drops due to 4 possible reasons?
|
cancers, spinal cord injury, heavy metal poisoning, immunosuppression
|
|
Chicken pox is an ___disease
highest incidence between __&__ ages?for shingles too? |
endemic
marcha and april 5-9; over 45 |
|
how is it spread?
|
repiritory; and contact w/ lesions
|
|
genome for warts effects the body how?
|
it integrates itself into the DNA-lifelong
|
|
what is dermatophytes?
|
fungal skin disease; fungi that invade keratinized tissue
|
|
what is dermatomycosis?
|
fungal skin disease; fungi that invade the deeper tissues of the skin
|
|
ringworm is an example of a?
what is the genus name for ringworms? tinea capitus? |
dermatophyte
-tinea -scalp ringworm |
|
fungal skin disease(ex:ringworm): is spread by? often difficult to __? is treated w/ ?
|
contact
-eradicate -anti-fungals - |
|
tinea pedis is what?
how do u prevent? is it contagious? |
-athelete's foot, fungal infection
-prevent by keeping feet clean&dry; highly contagious |
|
what are the 2 subcutaneous fungal infections?
|
sporotrichosis and blastomycosis
|
|
which subcutaneous fungal infection is from plants&common in the Mississippi valley?
|
sporotrichosis
|
|
what subcutaneous fungal infection is common in the soil of teh central and southeastern states?
|
blastomycosis
|
|
what's known as the "rose-gardeners disease?"
|
sporotrichosis
|
|
what is granuloma?
|
the interaction between tissue and blood cells
|
|
how does blastomycosis enter the body?
|
through the skin&lungs
|
|
candida can also invade __ if they are under water for long periods of time
|
nails
|
|
candida is very common in ____
|
aids patients
|
|
what is madura foot caused by?
|
true fungi&actinomycetes
-occurs in tropics -amputation often necessary(remember the pic!!!) |
|
what is swimmer's itch caused by?
|
schistosomes
-occurs throughout the Midwest especially in the grate lakes area -organism only grows close to shore -organism burrows in skin |
|
what are ophthalmia neonatorums?
|
pryogenic eye infections of the newborn
|
|
define Keratitis?
|
an inflammation of the cornea-can progress to blindness
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what disease is the leading cause of preventative blindness in teh world?
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trachoma
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how many ppl have trachoma?
how many are already blind? |
500mill
20mill |
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what are 2 ways of transfer of trachoma?
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flies(as vectors)
-human transfer |
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what are the 2 different types of parasitic eye disease?caused by wat?
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river blindness: a larvae of roundworm
loaiasis: caused by loa loa worm |
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what is the vector for river blindness?
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black flies
-in some villages almost all of the ppl who reach age 30 are blind |