Opportunistic viral infections Flashcards
Which group of pts are affected by opportunistic viral infections?
Immunodeficient
What are the 2 types of immunodeficiency?
- Innate (primary)
- Acquired (malignancy, HIV, steroids, chemotherapy)
How do more severe viral infections present?
Wider range of systems affected
More varied manifestations
What are the 3 stages of PCR?
1) Denature
2) Primer annealing
3) Chain elongation (with Taq polymerase)
List the 3 origins of opportunistic viral infections post-transplant
- Reactivation of latent infection (eg herpes)
- Graft introduced infection (eg hep B)
- Exogenous opportunistic infection post-transplant (eg measles)
Herpes viruses cause lifelong infection, which cell types do HSV, VZV, CMV and EBV reside in?
HSV/VZV: neurons
CMV/EBV: leucocytes
Name 2 complications VZV can cause in the immunocompromised?
Pneumonitis
Hepatitis
What is the treatment for VZV?
Acyclovir
How can VZV be prevented?
Varicella zoster immunoglobulin
When is there a risk of CMV in solid organ transplant?
Seropositive donor and seronegative recipient (due to recipient virus exposure)
When is there a risk of CMV in bone marrow transplant?
Opposite: risk when seronegative donor but seropositive recipient. (protective antibodies in recipient are removed by chemo/radiotherapy, but not replaced by seronegative donor)
How is CMV diagnosed?
PCR for viral load
What is the treatment for CMV?
Ganciclovir
OR
Foscarnet/cidofovir
What risk is posed by EBV in a transplant situation?
Post-transplant lymphoproliferative disease - control of proliferation of latently infected B cells is lost
What risk is posed by EBV in HIV +ve pts?
Oral hairy leukoplakia
Lymphomas
