infectious diseases

Question 1

classes of infectious agents?

Answer 1

bacteria, virus, fungi, yeast, parasites, prions

Question 2

organisms capable of living in any tissue?

Answer 2

staph aureus; makes coagulases

Question 3

organisms capable of releasing products that damage widely?

Answer 3

escherichia coli; produces endotoxins that spread via the blood stream.

Question 4

organisms that live/ reproduce in very few tissues?

Answer 4

influenza virus, aspergillus spp, clistridium spp.

Question 5

how does influenza virus cause disease?

Answer 5

binds to sialic acid on respiratory mucosa

Question 6

how does aspergillus spp. cause disease?

Answer 6

they sporulate when in contact with air

Question 7

how does clostridium spp cause disease?

Answer 7

in hypoxic conditions

Question 8

examples of organisms that damage only certain tissues?

Answer 8

clostridium difficile, clostridium botulinum, vibro cholera

Question 9

how does c.diff cause disease?

Answer 9

releases enterotoxins that damage large intestine mucosa

Question 10

how does clostridium botulinum cause disease?

Answer 10

releases a toxin ingested with food

Question 11

how does vibro cholera cause disease?

Answer 11

toxin activates cyclic ATP, causing loss of fluid from intestinal lining

Question 12

bacteria that damage tissue?

Answer 12

staph aureus; coagulase/ promote blood clotting. strep pyogenes; promote plasminogen activation decreasing clotting and healing. various bacteria; break down ECM framework

Question 13

what are aggressins?

Answer 13

non-toxic material that enhance survival of the organism

Question 14

how do viruses damage tissue?

Answer 14

direct cytopathic effects e.g. influenza, hep A. immune reactions e.g. hep B and C. incorporation of viral genes into host genome e.g. oncogene viruses

Question 15

example of organism causing fungal infections

Answer 15

aspergillus spp

Question 16

describe different fungal infections?

Answer 16

asthma; airway colonisation. aspergilloma; fungal ball in pre-existing cavity such as sinuses. hepatocellular carcinoma; aflatoxins from A flavus

Question 17

what organism causes yeast infections?

Answer 17

candida albicans

Question 18

examples of yeast infections?

Answer 18

local; thrush - caused by poor hygiene, bacterial flora alterations and diabetes. systemic; immunosupressed

Question 19

examples of parasites?

Answer 19

protozoa, trematodes (flukes), nematodes (roundworms), cestodes (flatorm or tapeworm)

Question 20

examples of protozoal diseases? (parasitic disease)

Answer 20

amoebiasis, giardiasis, malaria, trichomonas

Question 21

describe the parasitic disease; amoebiasis

Answer 21

colon colonisation causing amoebic dysentery. amoebic abscesses can occur on the liver

Question 22

describe the parasitic disease; giardiasis

Answer 22

small intestinal infection causing diarrhoea and weight loss

Question 23

describe the parasitic disease; malaria;

Answer 23

spread by mosquitoes. colonises red blood cells and can obstruct cerebral capillaries.

Question 24

describe the parasitic disease; trichomona’s

Answer 24

venereal transmission - a form of STD

Question 25

describe different types of ‘worms’

Answer 25

roundworms - enterobius vermicularis organisms.
tapeworms - diphyllobothrium latum organism causing vitamin B12 deficiency. echinococcus granulosus; dog tapeworm causing liver cysts

Question 26

what are prions?

Answer 26

infectious particles with no RNA or DNA

Question 27

describe sepsis?

Answer 27

an overwhelming response to infection where the body damages its own tissues.

Question 28

signs and symptoms of sepsis?

Answer 28

temp >38.3C or <36C, HR >90bpm, respiratory rate >20

Question 29

signs of severe sepsis?

Answer 29

low urine output, change in mental status, low platelet count, difficulty breathing, abnormal heart pump functioning, abdominal pain. septic shock.

Question 30

causes of sepsis?

Answer 30

pneumonia, abdominal infection, kidney infection, bacteraemia

Question 31

what can interfere with the body’s defences?

Answer 31

loss or suppression of cough reflex, pulmonary oedema, bronchial obstruction, dead air space