infectious disease clinical pathology case - lecture notes - julia

Question 1

x-ray has bilateral fluffy infilatrates. what type of infection is this likely to be?

Answer 1

• mononuclear inflammation in interstitium

Question 2

if lung looked like this, what would the diagnosis be?

Answer 2

• Lung abscess from mixed aerobic/anaerobic infection
• does look like lobar pneumonia, but has a cavity in this picture (radiolusency = consolidation begins to break down and forms cavity - also seen in TB) which is not characteristic of pneumia

Question 3

what does this sputum pattern signifiy?

Answer 3

• squamous cells and mixed bacteria come from the upper respiratory tract
• if columnar ciliated cells, would be from the lower respiriatory tract, but since there aren’t a lot in this sputum, there’s not a lot
• common to find mixed bacteria flora cause theres lots of different bacteria colonizing our mucosa

Question 4

in what patients does Pneumocystis jirovecii cause disease?

Answer 4

• patients with immunosuppression

Question 5

how do you sample Pneumocystis jirovecii?

Answer 5

• induced sputum or bronchoalveolar lavage

Question 6

what type of inflammation would you expect to see with pneumocystis jirovecii?

Answer 6

typically little inflammation

Question 7

what increases the risk of ecthyma gangrenosum? why?

Answer 7

neutropenia because it decreases the acute inflammatory response

Question 8

what will pseudomonas folliculitis cause? how do you get it?

Answer 8

• aka hot tub folliculitis - common water organisms
• enters skin through hair follicles
• cause painful infection, but not dangerous
• creates microabsesses

Question 9

what physical signs would you look for to identify CMV infection?

Answer 9

• in retina, would see white fluffy areas
• could be due to other viruses also
• but if patient had CMV in blood, then likely due to CMV

Question 10

how would you definitively diagnose CMV?

Answer 10

• look for inclusions in tissue biopsy
• serologic evidence = positive IgG antibody
• use quantitative measure of CMV in viral load in peripheral blood using quantitative PCR

Question 11

what process is occuring in this patient? what could be the cause?

Answer 11

• necrosis and acute inflammation
• toxoplasma encephalitis
• image indicates a “ring enhancing” lesion at the junction of the gray and white matter
• due to toxoplasma gondii protozoan
• causes lesions
• almost always a reactivation of previous infection

Question 12

what does toxoplasma gondii cause?

Answer 12

• encephalitis
• necrosis of neurons and microglial cells
• variable acute inflammatory reaction
• these are intracellular paracites

Question 13

how would you treat toxoplasma gondii?

Answer 13

can be controled but not eradicated by antifolate drugs