Opportunistic Viral Infections Flashcards
What are endogenous viral infections?
Latent viruses that reactivate in absence of immune system.
Acquired in past prior to immune suppression e.g. Varicella Zoster.
What are exogenous viral infections?
Viruses acquired from environment.
Increased severity in immunosuppressed e.g. Influenza, SARS-CoV-2.
What is indirect detection of a virus?
Response of the immune system to the virus.
These tests are useful to see if you have ever had the infection.
What is direct detection of a virus?
Fragments of the actual virus.
- Viral proteins (lateral flow/antigen tests).
- Viral genetic material (the virus genetic material present with patient sample.
Polymerase chain reaction.
These tests are useful to see if you have the infection now.
How is serology used to determine infection with a virus?
Measure levels of antibody in patients serum.
- +++ IgM indicate Active or Resolving infection
- +++ IgG indicates past infection > 6 weeks ago
Antibody levels ↓↓↓ reduced in Immunosuppressed.
Serological course may differ depending upon virus.
What does this mean?
Surface antibody declines in the future, core antibody remains high for Hep B.
Surface antibody indicates previous vaccination, core antibody is previous infection with the real thing.
If the immune system is compromised, what happens to serology?
Serology is useless.
Which antibodies are screened in serological screening?
- HIV Ag/Ab
- HBV surface antigen
- HBV core antibody
- HBV surface antibody
- HCV antibody
- EBV antibody
- CMV antibody
- HSV antibody
- VZV antibody
- HTLV antibody
What is monitored/prophylactically treated during immunosuppression?
- CMV monitoring PCR or prophylaxis
- EBV monitoring PCR
- BK monitoring PCR (Renal & BMT)
- Adenovirus monitoring PCR (Paediatric BMT)
- HSV prophylaxis if indicated
A 51-year-old with a recent HSCT is unwell. Which is the most appropriate test? ALT = 800 IU/mL
A. EBV IgG/IgM
B. HBV sAb
C. Parvovirus PCR
D. HEV PCR
E. CMV IgG/IgM
D. HEV PCR
What increases the risk of opportunistic infections, from highest to lowest?
Allogeneic stem cell transplant
Advanced HIV infection (CD4 dep)
Solid organ transplant
Various monoclonal antibody therapies
Cytotoxic chemotherapy
DMARDs and steroids
What are sources of viral infection from transplants?
Viruses acquired from graft: HBV
Viral reactivation from the host: HSV
Novel infection from infected individual: VZV
Which type of immunosuppression carries the greatest relative risk of developing a viral infection?
A. Steroids
B. Solid organ transplant
C. Allogeneic stem cell transplant
D. Monoclonal antibody therapies
E. Cytotoxic chemotherapy
C. Allogeneic stem cell transplant
What is screened for in symptomatic screening in the CSF?
- HSV
- VZV
- Enterovirus
- EBV
- CMV
- Adenovirus
- HHV6
- JC virus
What is screened for in symptomatic screening in the blood?
- CMV
- EBV
- Adeno
- HHV6
- Parvo
What is screened for in symptomatic screening in the respiratory system?
- Flu A/B
- Paraflu 1-4
- Adenovirus
- Enterovirus
- RSV
- HMPV
- Rhinovirus
- Coronaviruses
- CMV in BAL
What is screened for in symptomatic screening in the gut?
- HSV
- CMV
- Adeno
How are viral infections different in the immunocompromised?
- Present differently
- Disseminated
- Different organs
- More severe
- Oncogenic
- Lack of immune mediated symptoms.
What are issues with HSV infections in immunocompromised patients?
- Increased frequency
- Increased severity /risk of dissemination
- More organs can be involved (pneumonitis, eosophagitis, hepatitis); NB: not enceph!
- Increased risk of acyclovir resistance
What is the management of the HSV in immunocompromised patients?
HIV/AIDS: CD4 <200
Prophylaxis:
- Test for HSV IgG
- Bone marrow
- 1 month (until engraftment)
- Solid organ
- 3-6 months
- And if treated for rejection
What can varicella cause in immunocompromised patients?
- Pneumonitis
- Encephalitis
- Hepatitis
- Purpura fulminans in neonate
What can VZV cause in immunocompromised patients?
Zoster (shingles)
- Multi-dermatomal/disseminated
- Often a late presenting immunosuppression
What is the prophylactic management for VZV?
Prophylaxis (prolonged if post-bone marrow)
PEP - Post-exposure prophylaxis
Vaccination
What is the treatment for VZV?
Varicella:
- Anti-viral for 7-10 days
- IV until no new lesions; PO until all crusted
Zoster:
- Anti-viral (IV if disseminated) + analgesia
- If Ramsay-Hunt: Add steroids
- If HZO: Add topical steroids
A patient who received a stem cell transplant 2 weeks ago presents with mouth ulcers. Which of the following viruses would you test for on the mouth swab?
A. Enterovirus
B. Adenovirus
C. Herpes simplex type 1
D. Human herpesvirus 6
E. Human gammaherpesvirus 8
C. Herpes simplex type 1
What is EBV associated with?
Post-transplant lymphoproliferative disease (PTLD)
Latently infected B cells – polyclonal activation.
Predisposes to lymphoma.
Suspicion on rising EBV viral load (> 105 c/ml) and CT scan.
Confirmation with biopsy of lymph nodes.
What are complications associated with EBV?
Oncogenesis:
- B-cell latency, high turn-over
- T-cells monitor/control this
B-cell lymphomas
PTLD (post-transplant lympho-proliferative disorder
What is the management of EBV?
Monitor EBV levels
Investigate for lymphoma as needed
Rx:?Rituximab, reduce immunosuppression.
What are complications associated with CMV?
HIV/AIDS: CD4 <50
- Ocular (retinitis)
- Polyradiculopathy
- Pneumonitis
- GI tract
Solid Organ Transplant
- Allograft disease
- GI tract (i.e. renal)
What is the management for CMV?
Prophylaxis (i.e. lung transplant).
Pre-emptive treatment (i.e. renal transplant / HSCT).
Treat if disease (HIV/AIDS).
Rx: Ganciclovir/Valganciclovir, Reduce immunosuppression.
What is the treatment of CMV in HSCT?
CMV viral load twice weekly, treat if virus reactivates until suppressed (pre-emptive therapy).
What is the treatment of CMV in Solid Organ Transplant?
Valganciclovir prophylaxis for 100 days
What is the treatment for CMV?
- Ganciclovir (IV): Bone marrow suppression
- Valganciclovir: Oral
- Foscarnet (IV) (nephrotoxicity)
- Cidofovir (nephrotoxicity)
- IVIg (with another drug for pneumonitis).
Which of these is NOT an antiviral?
A. Sotrovimab
B. Valganciclovir
C. Foscarnet
D. Rituximab
E. Tenofovir
D. Rituximab
What is JC Virus (John Cunningham)?
JC virus is a polyomavirus.
Progressive multifocal leukoencephalopathy.
Effective antiretroviral therapy has drastically reduced PML incidence in HIV+ve patient.
PML can be seen in other types of immunosuppressed:
- Humanised monoclonal antibodies
- Natalizumab (for treatment of multiple sclerosis)
What is progressive multifocal leukoencephalopathy (PML)?
Cognitive disturbance, personality change, motor deficits other focal neurological signs.
Demyelination of white matter → neurological deficits.
Diagnosis: MRI and PCR on CSF
What is BK virus?
- Polyomavirus
- Double stranded DNA
- BK cystitis post SCT
- BK nephropathy post Renal Tx
Which patient has previously had Hepatitis B Infection?
sAg= Surface antigen cAb = core antibody sAb= Surface antibody
A. sAg+, cAb+, sAb-
B. sAg-, cAb-, sAb+
C. sAg-, cAb+, sAb-
D. sAg-, cAb-, sAb-
E. sAg+, cAb-, sAb-
C. sAg-, cAb+, sAb-
