HHV-6 Meningoencephalitis in a Healthy Adult Female

INTRODUCTION: We describe the case of a 47-year-old female who presented to an academic tertiary emergency department with two to three days of worsening fever, headache, malaise, and rigors. A broad infectious workup revealed a diagnosis of Human Herpesvirus 6 (HHV-6) meningoencephalitis without any additional identifiable causes. HHV-6, the virus responsible for the childhood disease roseola, is a common cause of fever, seizures, diarrhea, and a characteristic faint-pink rash in children. Symptomatic HHV-6 infection in adults is far less common. We believe this represents one of only a few reported cases of HHV-6 meningoencephalitis in an immunocompetent host. Case Report. A 47-year-old female presented to the emergency department with two to three days of fever, headache, malaise, and rigors. She had a noncontributory medical, surgical, and family history but had traveled extensively in northeast Africa six months prior. A physical exam was notable for a wide based gait, photophobia, mild nuchal rigidity, and pain with active range of motion of the neck. A broad infectious workup was pursued; however, given headache, fever, and subjective nuchal rigidity, the highest concern was for meningoencephalitis. A lumbar puncture was positive for HHV-6 without any other diagnostic findings to otherwise explain the patient's symptoms. The patient was discharged on hospital day 3 with improving symptoms. CONCLUSION: HHV-6 meningoencephalitis has previously been described as a pathogen associated with individuals with immunosuppressive conditions. There have been several prior case reports of symptomatic meningoencephalitis in immune-competent individuals, and we believe this case adds to a growing body of evidence that HHV-6 meningoencephalitis can cause symptomatic infection in a broader patient population.