Viral encephalitis in adults - Guideline for the diagnosis and management of
|Last review: 27/04/2018|
|Next review: 27/04/2021|
|Approved By: Improving Antimicrobial Prescribing Group|
|Copyright© Leeds Teaching Hospitals NHS Trust 2018|
This Clinical Guideline is intended for use by healthcare professionals within Leeds unless otherwise stated.
Guideline for the diagnosis and management of viral encephalitis in adults
Viral encephalitis in adults
Criteria for use of guidelines:
Duration of treatment
Switch to oral agent(s)
The outcome of patients with HSV encephalitis has been shown to be dramatically improved with Aciclovir treatment. Delays in starting treatment, particularly beyond 48 hours after hospital admission, are associated with a worse prognosis.
The empiric treatment of adults suspected to have viral encephalitis is:
Treatment should be started if the initial CSF and/or imaging findings suggest encephalitis or within 6 hours of admission if these results will not be available, or if the patient is very unwell or deteriorating.
If the first CSF microscopy is normal but the clinical suspicion of HSV or VZV encephalitis remains, Aciclovir should still be started within 6 hours of admission.
At present, there is insufficient evidence to recommend use of steroids in patients with HSV encephalitis.
No specific treatment is needed for VZV cerebellitis. For VZV encephalitis, whether due to primary infection or reactivation, intravenous aciclovir 10mg/kg 8 hourly is recommended, with or without a short course of corticosteroids. If there is a vasculitic component, there is a stronger case for using corticosteroids.
No specific treatment is recommended for enterovirus encephalitis. In patients with severe disease pleconaril (if available) or intravenous immunoglobulin may be considered, but would require discussion with an immunologist.
CNS Cytomegalovirus infections should be treated with ganciclovir, foscarnet or cidofovir.
Discontinuing antiviral therapy
Antiviral therapy may be discontinued in an immunocompetent patient if:
Encephalitis should be considered in immunocompromised patients with altered mental status, even if the history is prolonged, the clinical features are subtle, there is no febrile element, or the CSF white cell count is normal. MRI should be performed as soon as possible in all immunocompromised patients with suspected encephalitis.
Immunocompromised patients with encephalitis caused by HSV-1 or 2 should be treated with intravenous Aciclovir for at least 21 days, and reassessed with a CSF PCR assay. Following this, long term oral treatment may be considered depending on the clinical circumstance, for example, until the CD4 count is >200x106/L in HIV positive patients.
|Duration of Treatment|
|Switch to oral agent(s)|
There is no recommendation to switch to oral Aciclovir *
|Clinical condition:||Viral encephalitis|
|Target patient group:||Adults|
|Target professional group(s):||Primary Care Doctors
Secondary Care Doctors
This guideline is an adaptation of The Encephalitis Society Professional Guidelines for the Management of Suspected Viral Encephalitis in Adults, which is a synopsis of:
Solomon T., Michael B.D. (joint first), Smith P.E., Sanderson F., Davies N.W.S., Hart I.J., Buckley C., Holland M., Easton A., Kneen R., Beeching N.J. On behalf of the National Encephalitis Guidelines Development Group. Management of suspected viral encephalitis in adults: Association of British Neurologists and British Infection Association National Guideline. Journal of Infection 2012; 64(4):347-73.
Reference has also been made to:
International Herpes Management Forum (2004). Herpes Infections of the Central Nervous System. Herpes 11(supp 2):1470-1537
Whitley, R.J. (2006). Herpes simplex encephalitis: Adolescents and adults. Antiviral research 71:141-148.
A. Meta-analyses, randomised controlled trials/systematic reviews of RCTs
B. Robust experimental or observational studies
C. Expert consensus
D. LTHT consensus
Improving Antimicrobial Prescribing Group
LHP version 1.0
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