Viral Infections Flashcards
How does CMV usually present in an immunocompetent host?
Mostly asymptomic
Can have fever, lymphadenopathy and lymphocytosis
`What are the complications of congenital/neonatal CMV infection?
IUGR, pneumonitis, thrombocytopaenia, microcephaly, chorioretinitis, SNHL
What are the risk factors for CMV infection in immunocompromised hosts?
D+/R- (in solid organ transplant) D-/R+ (in stem cell transplants) Antilymphocyte induction drugs Age Comorbidities Immune status Genetics
What are the indirect effects of CMV infection in a transplant patient?
Allograft injury, allograft rejection, opportunistic infections
What is the mechanism of action of ganciclovir and valganciclovir?
Inhbits CMV DNA polymerase
What anti viral is used when there is resistance to ganciclovir/valganciclovir?
Foscarnet
What malignancies are associated with EBV?
Post transplant lymphoproliferative disease Nasopharyngeal carcinoma Hodgkins lymphoma Gastric carcinoma Oral hairy leucoplakia Burkitt’s lymphoma
What are the treatment options for post transplant lymphoproliferative disease?
Reduction in immunosuppression Antiviral agents IVIG Rituximab Chemotherapy Immunotherapy
When is varicella infectious?
48 hours prior to development of rash and 4-5 days after crusting of the lesions
What are the clinical features of uncomplicated varicella?
Prodrome of fever, malaise, pharyngitis
Generalised vesicular itchy rash
What are the complications of varicella?
Bacterial skin infection
Encephalitis
Pneumonia
What is the management of varicella in adults?
Uncomplicated – oral acyclovir or valacyclovir
Complicated or immunocompromised – IV acyclovir
What post exposure prophylaxis should pregnant women receive for varicella?
Varicella immunoglovulin if < 4 days and non immune
Consider oral acyclovir if exposure > 4 days
What is the treatment for herpes zoster?
Valacyclovir or acyclovir
Who should be vaccinated against herpes zoster?
Elderly patients regardless of chicken pox or zoster history
When is measles infectious?
From 5 days prior to rash until 4 days after
What are the clinical feature of measles?
Prodrome – fever, conjunctivitis, cough, coryza abd koplick spots
Exanthema phase – erythematouys blanching macular rash that begins on face and descends
What are the complications of measles?
Pulmonary – croup, bronchopneumonia, sinusitis, bronchiectasis
Neurologic – encephalitis, sub-acute sclerosing pan-encephalitis
What is the treatment for measles?
No effective proven specific treatment but give vitamin A and ?ribavirin
What are the clinical features of encephalitis?
Change in mental state for >24 hours, fever, unexplained seizures, focal neurology
What are the early complications of encephalitis?
Seizures Cerebral oedema Raised ICP Hydrocephalus Hypothalamic disturbance (SIADH, temperature)
What are the late complications of encephalitis?
Persistent neurocognitive sequelae (e.g. cognitive impairment)
Post infectious autoimmune encephalitis (usually associated with HSV)
What is the best predictor of mortality in encephalitis?
Level of consciousness
What are the most common viral causes of encephalitis?
HSV, VZV, enteroviruses
What are the common types of autoimmune encephalitits?
Anti-NMDA ADEM AHLE Anti-LGI Anti-Caspr2
Which antibody is associated with small cell lung cancer paraneoplastic encephalitis?
Anti-Hu
Which antibody is associated with testicular cancer paraneoplastic encephalitis?
Anti-Ma2
What specific history questions should be asked for patients with encephalitis?
Travel, animal exposure, immunocompromised, vaccination history, recent rash, features of malignancy
What is the sensitivity of HSV PCR on CSF?
96%
What are the classic CSF findings for viral encephalitits?
Lymphocyte predominant, normal glucose, mildly elevated protein
Which area of the brain is typically affected in HSV encephalitits?
Temporal
Which area of the brain is typically affected in autoimmune/paraneoplastic encephalitis?
Limbic
What is the management for new unexplained encephalitis?
Acyclovir pending aetiological confirmation
Supportive treatment – anti epileptics, antibiotics if suspect meningoencephalitis, management of raised ICP
What is the management for ADEM?
IV methylprednisolone
What is anti NMDA receptor encephalitits associated with?
Ovarian teratoma
What is ADEM (acute disseminated encephalomyelitis) associated with?
Measles
What are the EEG findings for ADEM?
Diffuse slowing
What are the MRI findings for ADEM?
White matter lesions
What antibody is found in ADEM?
Anti-MOG
What is AHLE?
Acute haemorrhagic leuco-encpehalopathy
A severe rapidly progressive form of ADEM, a necrotising vasculitis
