pathology of infectious diseases III - lecture notes - julia

Question 1

what are schistosomas? where are they found?

Answer 1

• found in tropical fresh waters
• bloodflukes - live in blood stream of host

Question 2

how do schistosomias invade hosts and grow?

Answer 2

• invasive larva penetrates skin
• adults develop in mesenteric veins
• adopt host antigens => very little inflammation
• deposit eggs

Question 3

how do schistosomias cause disease? what immune factors are involved?

Answer 3

• egg antigens elicit eosinophilic infiltrate, granulomas, and dense fibrosis
• results in relesase of IL-4, IL-5, IL-13

Question 4

what is the clinical consequence of schistosomia infection?

Answer 4

• pipe stem fibrosis in liver => protal hypertension, ascites
• bladder hematuria
• promotion of squamous cell carcinoma of bladder

Question 5

describe the life cycle of schistosomes. how are they transmitted?

Answer 5

• get into bladder of hosts
• lay eggs
• eggs urinated out
• get into fresh water
• have intermediate stage in snail
• cercariae released from snails
• these can get through skin of people working in the water

Question 6

what does a schistosome egg look like?

Answer 6

• little spike off of it is characteristic
• surrounded by eosinophil rather than neutrophils (he said to just take his work on this - we shouldn’t be able to tell from the picture)

Question 7

how does the granuloma around schistosome eggs differ from tuberculin granulomas?

Answer 7

• lots more eosinophils
• does have CD4 cells that have epithelioid morphology
• also more collagen
• great big pink cells surrounding egg are epithelioid cells surrounding granuloma

Question 8

how do granulomas around schistoma eggs develop?

Answer 8

IL-4 and IL-13 that are characteristic of worm infection stimulates much more collagen synthesis than that seen in the inflammation due to TB

Question 9

where are schistosoma most likely to be found within the body?

Answer 9

• adults in mesenteric vein
• eggs tend to go to liver
• in chronic disease liver had greatest burden of eggs in it

Question 10

what agents cause cytopathic/cytoproliferative disease?

Answer 10

viruses

Question 11

how is influenza spread?

Answer 11

• droplets
• not stable when dry (as opposed to TB, which is transmitted by aerosol and is relatively stable when dry)

Question 12

what do lung xrays of patients with influenza pneumonia look like?

Answer 12

• not localized to just one lung
• infiltrates less dense, “fluffy”
• intestitial inflammation