Sketchy Micro: Polyomavirus

Question 1

List the two Poyomaviruses.

Answer 1

• JC virus (Julius Caesar)

* BK virus (Brutus’s Knife)

Question 2

Describe the structure or Polyomavirus.

Answer 2

• Naked (statue of David and Julius Caesar’s rob falling off)
• Circular genome (round room with DNA curling around the top)
• dsDNA (blue tones with double-stranded helix at top)

Question 3

In whom does JC virus cause problems?

Answer 3

Over half the population is infected with JC virus, but it only causes PML in those with HIV whose CD4 counts drop below 200.

(Think of the cane that Caesar has and the “senator count 200” sign on the wall.)

Question 4

How does JC virus exert its damage?

Answer 4

It causes death of oligodendrocytes in the CNS.

To help remember this, the table has been drawn with its bark peeling off, sort of like demyelination.

Question 5

What clinical findings are typical of PML?

Answer 5

Non-enhancing lesions on MRI (like the white laurel wreaths on the bust of Caesar)

Question 6

BK viruses causes what classic finding?

Answer 6

Hemorrhagic cystitis (like the cherub peeing blood)

BK virus can infect anywhere in the urinary tract (even the kidney –represented by the knife wound in Caesar’s flank).

Question 7

Which patients are at risk of BK infection?

Answer 7

Those with HIV or those who’ve received transplants

Think of the platter of falling organs next to the BK fountain to remember organ transplant.