Abstract
Acyclovir resistance is rarely seen in herpes simplex virus (HSV) type I encephalitis. Prevalence rates vary between 0.5 % in immunocompetent patients (Christophers et al. 1998; Fife et al. 1994) and 3.5–10 % in immunocompromised patients (Stranska et al. 2005). We report a 45-year-old, immunocompetent (negative HIV antigen/antibody testing), female patient, without previous illness who developed—after a febrile prodromal stage—aphasia and psychomotor slowing. Cerebral magnetic resonance imaging (cMRI) showed right temporal and insular T2-hyperintense lesions with spreading to the contralateral temporal lobe. Cerebrospinal fluid (CSF) analysis yielded lymphocytic pleocytosis and elevated protein level. Polymerase chain reaction testing for HSV type I showed a positive result in repeat lumbar puncture. HSV type I encephalitis was diagnosed and intravenous acyclovir treatment was initiated (750 mg t.i.d.). Acyclovir treatment was intensified to 1000 mg t.i.d., due to clinical deterioration, ongoing pleocytosis and progression on cMRI 5 days after initiation of antiviral therapy. In parallel, acyclovir resistance testing showed mutation of thymidine kinase gene at position A156V prompting foscarnet therapy (60 mg t.i.d.). Patient’s condition improved dramatically over 2 weeks. Acyclovir resistance is rare but should be considered in case of clinical worsening of patient’s condition. To our knowledge, this is the first report of acyclovir resistance in HSV type I encephalitis of an immunocompetent and previously healthy patient in Austria.
Highlights
Suspected acyclovir resistance of herpes simplex virus (HSV) type I was first described in 1982 (Burns et al 1982; Crumpacker et al 1982; Sibrack et al 1982) with reported prevalence rates of 0.5 % in immunocompetent patients (Christophers et al 1998; Fife et al 1994) and 3.5–10 % in immunocompromised patients.(Stranska et al 2005) Even higher prevalence rates (25 %) of acyclovir resistance have been published in bone marrow or allogenic hematopoietic stem cell transplant recipients (Danve-Szatanek et al 2004; Morfin et al 2004)
The patient suffered from HSV type I encephalitis and was initially treated with an intravenous acyclovir dose of 750 mg t.i.d
Acyclovir resistance in HSV type I encephalitis is rare in immunocompetent patients (Gateley et al 1990; Schulte et al 2010) but should be considered in cases of clinical deterioration despite antiviral therapy and persistent virus load in the Cerebrospinal fluid (CSF)
Summary
Suspected acyclovir resistance of herpes simplex virus (HSV) type I was first described in 1982 (Burns et al 1982; Crumpacker et al 1982; Sibrack et al 1982) with reported prevalence rates of 0.5 % in immunocompetent patients (Christophers et al 1998; Fife et al 1994) and 3.5–10 % in immunocompromised patients.(Stranska et al 2005) Even higher prevalence rates (25 %) of acyclovir resistance have been published in bone marrow or allogenic hematopoietic stem cell transplant recipients (Danve-Szatanek et al 2004; Morfin et al 2004). A 45-year-old woman suffering from right frontal headache, fever, diarrhea, and vomiting, without previous illness, was admitted to a district hospital She was evaluated for systemic viral disease with negative testing for putative pathogens including human immunodeficiency virus (HIV). Repeat CSF examination yielded ongoing lymphocytic pleocytosis (243 cells/μL) and this time positive PCR result for HSV type I. At transferal to a specialized neurological rehabilitation facility 1 month after hospital admission the patient still showed residual aphasia, left-sided hemiparesis, and cognitive dysfunction. She left rehabilitation center with modified Rankin scale of 3 (moderate disability)
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
