Microbiology 15: Antiviral Therapy Flashcards
What disease does EBV cause ?
Infective mononucleosis
Where does Varicella Zoster Virus lay dormant in the body?
Dorsal root ganglia
What is a complication of Chickenpox in adults?
Varicella pneumonitis
What is a complication of shingles in adults ?
Post-herpetic neuralgia
Which medication is 1st line for treatment of HSV and VZV ?
Aciclovir
What type of anti viral is acyclovir ?
Nucleoside analogue
They get incorporated into growing chain of DNA causing it to terminate
Give 2 reasons why aciclovir has reduced toxicity to normal cells compared to cells infected with a virus?
Aciclovir requires activation by viral thymidine kinase (found in cells infected by viruses)
Aciclovir has a higher affinity for Herpes virus DNA polymerase compared to human DNA polymerase
Which medical emergency is caused by HSV ?
HSV encephalitis
What is the characteristic histological appearance of CMV infection ?
Owl’s eye inclusions
Which virus are immunocompromised patients particularly at risk of compared to immunocompetent people ?
CMV
In which cells does CMV tend to lie dormant ?
Monocytes
Dendritic cells
What anti viral treatments are used to treat CMV infection ?
Ganciclovir
Foscarnet
Cidofovir
Which disease can EBV cause in immunocompromised patients ?
PTLD - post transplant lymphoproliferative disease
The EBV keeps dividing unless kept in check by the immune system
This causes polyclonal activation of B cells
What does PTLD predispose to ?
B cell lymphoma
What is the treatment for PTLD ?
Rituximab - monoclonal antibody against CD20 B cell surface marker
What are the 2 main surface proteins on influenza virus ?
HA- haemaglutinin
NA- Neuraminidase
Which disease is commonly caused by RSV ?
Bronchiolitis
Who should palivizumab be given to prophylactically ?
High risk infants (preterm, heart or lung disease, SCID) in the winter months
Prevents severe disease from RSV
Which 2 diseases does BK virus cause in immunocompromised patients?
Haemorrhagic cystitis in bone marrow transplant patients
BK nephritis in renal transplant patients
Which immunomodulatory therapy is used to treat hepatitis B ?
Interferon Alpha
Which antiviral drug is used to treat and prevent Influenza In the elderly?
Oseltamivir
Which antiviral can be used in aerosol form to prevent RSV infection in children with heart and lung disease ?
Ribavirin
Which ART is given to pregnant women with HIV ?
If already on ART don’t change it - most likely Zidovudine
Otherwise:
Nevirapine
Which antiviral is the drug of choice for CMV infection ?
Ganciclovir
What is the prodrug of aciclovir that can be used in VZV infection ?
Valaciclovir
Which antiviral drug is used to treat severe resistant herpes infection ?
Foscarnet
Which drug is effective against Influenza A but not Influenza B ?
Amantadine
Which HIV drug works by inhibiting reverse transcriptase by acting as a guanine analogue?
Zidovudine
treatment for HSV encephalitis
medical emergency
start empirical treatment with IV aciclovir 10 mg/kg tds without awaiting test results
treatment for HSV meningitis
usually self limiting
IV aciclovir 2-3 days, then switch to oral for 10 days
valaciclovir alternative in immunocompetent to avoid cannulation
indications for treatment for VZV
chickenpox in adults (risk of pneuonitis)
shingles in adults >50 yrs ( risk of post-herpetic neuralgia)
primary infection/reactivation in an immunocompromised patient
neonatal chickenpox
consequences of CMV in immunocompromised patients
bone marrow suppression, retinitis, pneumonitis, hepatitis, colitis, encephalitis
treatment for CMV infection
ganciclovir (IV) - S/E = BM toxicity
valganciclovir (PO)
foscarnet (IV) - nephrotoxicity
cidofovir (IV) - nephrotoxicity
describe how viruses gain entry into cells
HA mediated virus binding and entry into target cell
NA allows the release of progeny virus particles from the host cell
NA is the target for current anti-influenza drugs
treatment for RSV
(most common cause of bronchiolitis)
ribavirin - neucleoside analogue
IVIG - in immunocompromised
palivizumab - monoclonal ab against RSV
BK virus treatment
lifelong carriage in the kidneys and urinary tract
problems in the immunocompromised
BK haemorrhagic cystitis - bladder washouts, cidofovir IV
BK nephropathy - reduce immunosuppression and IVIG
adenovirus treatment
cidofovir IV
IVIR
brindcidofovir PO
immunoglobulin preparations for post-exposure prophylaxis
VZIG
hepatitis B ig
human rabies IG
