Fungal Meningits, Poliovirus, Polyoma Virus Flashcards
How do fungi get into CSF
from blood
treatment for fungal meningitis
amp B and flucytosine
cryptococcosis neoformans is transmitted by?
inhaled pigeon droppings
85% of pts with cryptococcosis neoformans infections have what underlying condition?
HIV
structure of cryptococcosis neoformans
encapsulated yeasts
**capsule is polysacchairde and anti-phagocytotic
initial pres of cryptococcosis neoformans CNS infection
asympomatic pulm infection
how is cryptococcosis neoformans CNS infection diagnosied?
yeasts with halos on india ink from CSF of pt
fungal agent responsible for steriod outbreak
Exserohilum rostratum
= environmentala black mold
structure of poliovirus
non-enveloped, icosahedral + RNA
how is polio tranmitted
fecal- oral route
reservior for poliovirus
humans
where in the body does poliovirus replicate once infected
lymphoid tissue of pharynx and gut (virus detected in throat and feces) –> viremia –> cross BBB and destroy motor neurons
what is post polio syndrome
inc weakness later in life
how are vaccine strains distinguished from wild poliovirus
strain specific polyclonal area (specialized labs only)
salk vs sabin vaccine
salk (IPV) = inactivated (by formalin); prevents reversion; protects against paralysis but NOT spread of wild virus
sabin (OPV) = live oral; protects againt paralysis AND spread of wild virus bit can be shed and revert and enter community
Which vaccine is used in US
Salk = IPV
global eradication program uses OPV
structure of polyoma virus
non-enveloped, icosahedral, dsDNA (circular genome)
where in the cell does the polyoma virus repliate
NUCLEUS
consequences of polyoma virus infection into permissive vs non-permissive cells
permissive = rep in nuc and lyse cell to release progeny
non-permissive = integrate into host genome and transform cell = tumor formation
genes responsible for transformation and immortilization of non-permissive cells
3 genes: small, middle, and large T antigens
immortalization = small and large T antigen transformation = small and middle T antigen
what do the early genes of polyoma virus encode? late?
early = T antigens late = structural protein
what are the 2 known human polyoma viruses
JC and BK
who gets infected with JC and BK virus? who gets cancer form them?
everyone gets infected but only AIDS and transplant pts get cancer
describe where the BK and JC viruses replicate in the body?
where they enter (GI or respiratory tract) –> viremia –> kidney, lung, brain
where do BK and JC virus have latent infection?
kindey
**in immunocomprosimed can lead to hemorrhagic cystitis
etiologic agent of PML
JC virus
What is PML
progressive demyelinating disease (lyses oligiodendrocytes) due to reactivation og JC virus
presentation of PML
over the course of a few weeks clumsiness, weakness, speech problems
diagnosis of PML made by
lesions in white matter on MRI
CSF or brain biopsy with PCR + for JC virus
prognosis of PML
transplant = 80% fatality in 6 mos HIV/AIDS = 50% in 6 mos due to HAART therapy
