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35 Cards in this Set
- Front
- Back
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Transmission by FINGERS?
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-Nasal secretions - Mucus (mechanical)
-Oral Secretions – saliva (mechanical) -Sores (active) when transferred directly. Passive when transferred indirectly (glove of a doctor) -Feces to fingers to Mouth |
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Transmission by FLIES?
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-Flies means any biological vector(roach, mice, rat, etc)
-Flies eat dog feces, then food, then bacteria grows out(passive) -Active examples- inc load and virulence(mosquitoes and malaria, bats and rabies) |
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Reservoir of infection?
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-Term used to describe active biological infections
-This means its a mode of transmission, but it also provides a means for the organism to grow and survive |
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Definition of FOMITES?
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-An inanimate object that provides a means of transmission, but not growth
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Transmission by FOMITES?
(6 examples) |
-Money- paper money is cidal or inhibitory and coins are cidal
-Gloves -Artificial Nails -Eating Utensils -Hankerchifs- Transmit strep and staff (much more dangerous than money) -Thongs |
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Transmission by FOOD?
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-Includes food and liquids
-Organisms can inc. in # on food -More of a reservoir than a source -Food gets contaminated by flies(not considered active b/c must be alive to be active) |
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Transmission by PHLEGM?
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-Hospitals are trying to control respiratory illness
-From sneezing, coughing, talking -96% of organisms that come out aren't pathogenic, but if it is, it needs an immunocompromised person -ID-50- infections douse fifty- this is what infects 50/100 people- ex)For TB this is about 10 bacilli and each drop after a cough has about 3 bacilli |
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How does eliminating the reservoir control infection?
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- Always eliminate the reservoir to control infection
-Black plague killed 100 million people in europe, this was b/c of the rat problem and people staying inside(contributed to spread of plague) |
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How are portals of entry related to salmonella typhi?
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-Causes Typhoid fever
-Get's in through GI tract and skin |
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How are portals of entry related to clostridium tetani?
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-Causes tetanus
-Ingest these everyday, but if it gets through skin, you get infected |
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How are portals of entry related to anthrax?
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-Deadliest when breathed in
-If it gets through skin then your tissue just dies |
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How is the skin a portal of entry?
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-First line of defense, many interlocking layers
-Dermatophytes and Stapholococcus aureus can go down through sweat gland and infect -Streptococcus pyogenes- Causes strep throat, fingers can contaminate vaginal area and if you give birth baby can rip the area and you become infected -Mosquitoes transmit malaria -If bitten by a tick, lots of infections can get in(Lyme disease, etc) |
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How is the respiratory tract a portal of entry?
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-Major portal of entry for diseases
-Covering your mouth will help prevent infection -TB gets in by sneezing -Bacterial pneumonas, haemophilius(meningitis), cold, flu, rubella(german measles), rubeola(measles), and smallpox all get in by way of droplet infection |
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How is the digestive tract a portal of entry?
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-Comes from food or water
-E. coli, salmonella, dysentary(shigella), cholera, typhoid, botulism -Hep. A is also transmitted by this oral fecal route |
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How is the urinary tract(genito) a portal of entry?
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-Venereal diseases- syphillis, gonorrhea, chlamydia
-Viruses- AIDS, herpes -Staphylococcus can colinate this area, Toxic shock syndrome comes from highly absorbent tampons that get contaminated, improper wiping, catheters can cause infection |
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How is infection controlled by breaking the link in transmission?
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-Cow- milk- TB- pasteurize
-Chlorinate pool water -Handwashing(stop spread of e. coli) -tetanus- produces spores that are resistant to everything. Does not hurt by ingestion, but it does when you puncture yourself |
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How is the Placenta a portal of entry?
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-The umbilical cord can transmit alot of disease
-STORCH- pneumonic to remember bacteria -Syphillus- mother has syphillus it is transmitted to baby(beethoven) -Toxoplasmosis- protozoa, passed on by cat feces -Others-AIDS, chylamydia, and Hep. B can cross placenta -Rubella- virus, causes german measles -Cyotomegalo virus- Problem for immuno compromised -Herpes- Herpes simplex 1 and 2(2 is genital herpes) |
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What is the period of incubation?
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-Inc in number or grow
-Time interval from when the organism enters you until the onset of symptoms -Some have short period like cold or flu -Most acute childhood infections have incubation periods of 1-3 weeks -6 months is the average incubation period -Leprocy- 2-5 years, but some take up to 40 years -AIDS- takes 8 years |
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How is the virulence of the organism related to the period of incubation?
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-If you increase the virulence, you shorten the length of incubation
-You inc. the virulence of the organism by passing it through the host -If you have an epidemic, that means it's passing from one person to the other -At the height of an epidemic, you shorten the incubation time to about one week(for something like chicken pox) |
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How is resistance of the host related to the period of incubation?
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-As you increase resistance of the host, you increase the incubation period
-If you have a high enough resistance, and the virulence is low enough, you are a healthy carrier and you get a subclinical dose(ex- strep and sore throat) -Rhinitis and Sinusitis-minor infection in nose |
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How is the distance from the entrance to focus of action related to the period of incubation?
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-Rabies has an incubation period from 1-2 months
-Main infection point is the brain, and the further away from the brain, the longer the infection |
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How is the amount of infectious agent related to the period of incubation?
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-Talking about load- The more organisms, the higher the load, the shorter the incubation period (You need the ID50(Infectious dose 50))
-Anthrax spores- need 8,000-10,000 spores to get the infection through the lungs -Salmonella- need 100,000-1 billion bacilli to get this- 1 in 3 packages of store bought chicken has this in it and if not refrigerated and cooked properly you can get this food poisoning |
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What is invasiveness?
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-The ability of the organism to spread throughout your body
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What is toxigenicity?
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-It means does the organism produce a toxin
-Syphillis- treponema pallidium(takes 25 years to kill you)- spreads through all tissues in body- has a low toxicity so it takes a long time to kill -Tetanus- Grows on rusty nail so not invasive, produces a very deadly toxin, a period sized amount can kill 30 people -Strep Pyogenes- very deadly, very invasive, and very toxic |
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What is exaltation?
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-This is when you can increase the virulence of the organism (becomes more infectious)
-Pass it through a susceptible host -Mutations, plasmids, and lysogenic conversion can increase the pathogenicty of an organism |
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What is attenuation?
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-Decreasing the pathogenicty of an organism
-Can do this by growing the organism under adverse conditions(dec the virulence of vaccine by growing on lab media) -Can also be done by varying temperature and exposing it to chemicals(low doses so you hurt it but not kill it) |
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What is acute?
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-Short onset and short lasting
-Examples of acute infections- colds, the flu, Hep. A |
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What is chronic?
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-Long onset and long lasting
-Hep. A, B, C- you may go 20-30 years w/out knowing you have thid -AIDS, HIV, and TB are also examples |
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What is a systemic infection?
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-The organism spreads through all tissues of your body
-Ex) Syphillis and lyme disease |
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What is a local infection?
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-Confined to one area
-ex)tetanus(step on rusty nail), boil(staphylococcus aureus), pimple(raised and red where staph is) |
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What is a focal infection?
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-It is when a local infection spreads to other parts of your body(Tetanus DOESN'T do this)
-A boil is focal- pop a pimple and it goes into blood (pus is WBCs who engulf bacteria)- staph uses WBCs as taxi -TB starts in lungs and eats lung tissue- can digest enough to enter blood and become secondary TB that is extrapulmonary(means TB outside of lungs) |
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What is septicemia?
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-Refers to presence of pathogens in blood
-Could have a bacteremia(pathogenic bacteria in blood) -Viremia- viruses in blood -You are not symptomatic yet |
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What is pyemia?
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-You have pyogenic organisms in your blood
-Pyogenic cocci done in lab- streptococci and staphylococci -This means it produces pus(pus is dead WBCs) |
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What is Toxemia?
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-You have a toxin in your blood
-Tetanus and Diptheria are examples |
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What is sapremia?
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-Means you are infected with a saprophyte
-Lives off dead tissue in live host -Occurs in gangrenous limbs -If you have a retained placenta(placenta not removed properly after birth) it can cause death |
