Opportunistic Viral Infections Flashcards
(97 cards)
What are the different types of immunodeficiency found in a host? (2)
Primary immunodeficiency.
Acquired immunodeficiency.
What is an example of a primary immunodeficiency?
UNC93B deficiency and TLR3 deficiency predisposes to herpes simplex encephalitis, epidermodysplasia verruciformis, SCID.
What are some examples of acquired immunodeficiencies? (4)
Solid organ transplantation.
Bone marrow transplantation.
Immunosuppressive drugs.
Advanced HIV infection.
In HIV, what can be used to predict the risk of developing specific opportunistic infections?
CD4 count.
What are some AIDS-defining illnesses? (8)
Invasive cervical carcinoma.
CMV disease (other than liver, spleen, or nodes)
CMV retinitis (with loss of vision)
HIV related encephalitis.
Herpes simplex: chronic ulcers, or bronchitis, pneumonitis or oesophagitis.
Kaposi’s sarcoma.
Burkitt’s lymphoma.
Progressive multifocal leukoencephalopathy.
What are some major classes of immunosuppressive agents (5)
Glucocorticoids or steroids.
Calcineurin inhibitors (T-cell function) (cyclosporine, tacrolimus).
Antiproliferative agents (azathioprine, mycophenolate mofetil (MMF) or mycophenolic acid (MPA), sirolimus)
Antibodies (depleting, and non-depleting)
Co-stimulation blockers.
What immunosuppressive state puts you at the greatest risk of acquiring an opportunistic viral infection?
Allogeneic stem cell transplant.
Advanced HIV infection.
Solid organ transplant.
What are the three points in time that a transplant patient can catch a viral infection.
Viruses acquired from graft e.g. HBV.
Viruses reactivated from host e.g. HSV.
Novel infection from infected individual e.g. VZV
How can you reduce the risk of virus acquisition from grafts? (2)
Serostatus.
Risk assessment.
How can you reduce the risk of viral reactivation from host following transplant? (4)
Serostatus.
Monitoring.
Prophylaxis.
Pre-emptive therapy.
How can you reduce the risk of novel infection from infected individuals infecting patients with organ transplants (5)
Isolation barrier nursing. Advice for family/contacts Post-exposure prophylaxis. Vaccinating contacts. Control of diet.
What organisms are screened for in pre-transplant serology (8)
HIV HBV HCV EBV CMV HSV VZV HTLV
What organisms are continuously monitored for post-transplant until discharge/recovery. (4)
CMV monitoring or prophylaxis.
EBV monitoring.
Adenovirus monitoring (paeds bone marrow transfusion - BMT)
HSV prophylaxis if indicated.
What organisms are detected in CSF (8)
HSV VZV Enterovirus EBV CMV Adenovirus HHV6 JC virus.
What organisms are detectable in the blood (5)
CMV EBV Adenovirus HHV6 Parvovirus
What organisms are detected in sputum (9)
Flu A/B Paraflu 1-4 Adenovirus Enterovirus RSV HMPV Rhinovirus Coronaviruses CMV in BAL
What organisms can be detected from stool samples (3)
HSV
CMV
Adenovirus
What is the challenge with treating opportunistic infections
They are often more difficult to treat
What is required when treating opportunistic infections (4)
Early treatment
Higher doses required
Longer courses of antibiotics required
Sometimes drug combinations are required
What is an increased risk of treating opportunistic viral infections
Increased risk of antiviral drug resistance
What viruses form part of the family of human herpes viruses (6)
Herpes simplex virus (HSV) 1 and 2. Varicella zoster virus (VZV) Cytomegalovirus (CMV) HHV6 (human herpes virus 6) Epstein Barr Virus (EBV)
What kind of viruses are human herpes viruses
DNA viruses
What is the danger of human herpes virus infections.
The virus establishes a latent infection that persists for the life of the host.
In the latent state only a small subset of the viral genes are expressed.
Reactivation with expression of viral proteins and production of new virus particles may occur at intervals to produce recurrent infections.
Post allo stem cell transplant, what is the first latent infection to recur
HSV
