265. Rocky Mountain Spotted Fever Encephalopathy

Abstract Background Rocky mountain spotted fever (RMSF) is a rickettsial disease with incidence of 11 per million and is rarely associated with encephalopathy. Here we discuss a patient with RMSF encephalopathy, highlighting the natural course. Methods A 54 year old man with history of hypertension and chronic progressive external ophthalmoplegia, presented with waxing and waning confusion, headache, slurred speech, agitation and difficulty swallowing. He was afebrile and hemodynamically stable. Investigations showed leukocytosis of 15400 and mild transaminitis. Computed-tomography (CT) head was unremarkable. Lumbar puncture revealed normal pressure. Cerebrosopinal fluid (CSF) analysis was notable for WBC 7, glucose 76 and moderately elevated total protein 114. Urine drug screen was negative. Blood, fungal, and CSF cultures were sent and empiric therapy with vancomycin, ceftriaxone, ampicillin and acyclovir commenced, for suspected encephalitis. High dose solumedrol 1gm/day was given due to suspicion of autoimmune encephalitis. MRI brain showed cerebral atrophy. There was slight abnormal FLAIR/T2 signal within the medial aspect of the temporal lobes, right more than left. Results Occupational history revealed that he was a logger by profession, which steered our focus on tick borne diseases. Extensive serologic evaluation was requested and RMSF IgG titres came back positive at 1:512. Doxycycline was added, while ampicillin and ceftriaxone were discontinued. With doxycycline, patient made remarkable recovery and was discharged home well. However, he returned within 48 hours with recurring encephalopathy. His clinical presentation remained convincing for RMSF encephalitis, with the natural course of the illness spanning over weeks, with waxing and waning symptoms. Patient was managed with IV doxycycline for 72 hours following which he returned to his baseline mental status. Figure 1. MRI findings Figure 2. Serological investigations Figure 3. CSF studies Conclusion Patient’s occupation played a pivotal role in establishing diagnosis. In RMSF, IgM and IgG antibodies appear 7 to 10 days after the onset of the illness, and a fourfold rise in IgG is diagnostic of seroconversion and recent illness. Patient’s waxing and waning symptoms, persisting for weeks and remarkable response to doxycycline, are typical features of RMSF encephalitis. Disclosures All Authors: No reported disclosures

Results. Vitals revealed a temperature of 102°F. He was cachectic and a 0.5 cm right supraclavicular lymph node was palpable. No meningeal signs were appreciated. CD4 count was 50/µL (18%), HIV-1 viral load 2,969,945 copies/mL. Computed tomography (CT) of the abdomen/pelvis suggested lung and spleen involvement. Serum C. i enzyme immunoassay (EIA) was 1.38 ng/mL, immunodiffusion (ID) was positive and complement fixation (CF) titer was 1:256. C. i was isolated from expectorated sputum. CSF cell count was normal, but ID was positive and CF titer was 1:2 however, lab reported concern for spill-over due to high serum IgG titers. He left against medical advice with fluconazole 400 mg daily. He was hospitalized a month later for failure to thrive. MRI head revealed enlarged lateral and third ventricles with increased periventricular hyperintensity concerning for coccidioidal meningitis. Repeat serum studies were stable. CSF revealed CF 1:4 and C. i antigen by EIA 1.31ng/mL, distinguishing between spill-over and meningitis. Susceptibility results showed resistance to fluconazole and amphotericin B with minimum inhibitory concentrations (MICs) of 50 and 4 respectively, posaconazole susceptibility (MIC < 1) and itraconazole borderline (MIC 3.7). Despite amphotericin B resistance, it was used for bridge to posaconazole. ART was initiated after concern for immune reconstitution had resolved.
Conclusion. This case highlights the difficulty in making an accurate diagnosis of coccidioidal meningitis. It also describes a fluconazole-resistant C. i isolate in the setting of prolonged low-dose fluconazole therapy.
Methods. Single-center retrospective chart review. Cases were identified based on International Classification of Diseases (ICD)-10 diagnostic codes (intracranial abscess or granuloma, extradural and subdural abscess, Pott's puffy tumor, acute or chronic sinusitis) and by reviewing all microbiological samples of intracranial pus, tissue or fluid.
Conclusion. Intracranial complications of sinusitis continue to cause significant morbidity in children. The predominant causative pathogen was Streptococcus anginosus. Polymicrobial infections are common, confirming the need for prolonged broad-spectrum antibiotic treatment.
Disclosures Background. Rocky mountain spotted fever (RMSF) is a rickettsial disease with incidence of 11 per million and is rarely associated with encephalopathy. Here we discuss a patient with RMSF encephalopathy, highlighting the natural course.

Methods.
A 54 year old man with history of hypertension and chronic progressive external ophthalmoplegia, presented with waxing and waning confusion, headache, slurred speech, agitation and difficulty swallowing. He was afebrile and hemodynamically stable. Investigations showed leukocytosis of 15400 and mild transaminitis. Computed-tomography (CT) head was unremarkable. Lumbar puncture revealed normal pressure. Cerebrosopinal fluid (CSF) analysis was notable for WBC 7, glucose 76 and moderately elevated total protein 114. Urine drug screen was negative. Blood, fungal, and CSF cultures were sent and empiric therapy with vancomycin, ceftriaxone, ampicillin and acyclovir commenced, for suspected encephalitis. High dose solumedrol 1gm/day was given due to suspicion of autoimmune encephalitis. MRI brain showed cerebral atrophy. There was slight abnormal FLAIR/T2 signal within the medial aspect of the temporal lobes, right more than left.
Results. Occupational history revealed that he was a logger by profession, which steered our focus on tick borne diseases. Extensive serologic evaluation was requested and RMSF IgG titres came back positive at 1:512. Doxycycline was added, while ampicillin and ceftriaxone were discontinued. With doxycycline, patient made remarkable recovery and was discharged home well. However, he returned within 48 hours with recurring encephalopathy. His clinical presentation remained convincing for RMSF encephalitis, with the natural course of the illness spanning over weeks, with waxing and waning symptoms. Patient was managed with IV doxycycline for 72 hours following which he returned to his baseline mental status. Background. Human Herpesvirus-6 (HHV-6) seroprevalence rates in the United States range from 72-95%, but clinical illness in the adult population is extremely rare, which often presents as meningoencephalitis in immunocompromised hosts. The literature on HHV-6 encephalitis in immunocompetent adults is limited to a select number of case reports, ultimately providing scant treatment guidance for clinicians.
Methods. This is a unique case describing the clinical course of confirmed HHV-6 encephalitis in an immunocompetent host.
Results. The patient is a 77-year-old immunocompetent female presenting with two days of global aphasia and increased muscle tone. She presented hypertensive with a leukocytosis. Work-up for acute stroke was unremarkable, but lumbar puncture revealed an elevated white blood cell (WBC) count of 39 leukocytes/mm 3 with a lymphocytic predominance. BioFire FilmArray® Meningitis/Encephalitis panel (FAME) demonstrated positivity for HHV-6 with a viral load of 8,500 copies/mL in the cerebrospinal fluid (CSF) and 4.1 million copies/mL in serum. The patient experienced temporary improvement in her aphasia after being initiated on intravenous (IV) ganciclovir for 12 days. Shortly after the initiation of therapy, her aphasia worsened with repeat CSF studies demonstrating an increased viral load to 35,700 copies/mL. She was subsequently transitioned to IV foscarnet for HHV-6B coverage and discharged after completing 21 days of therapy with marked improvement in her symptoms. Two weeks later, the patient was readmitted for recurrence of aphasia. MRI brain at that time was unremarkable with repeat lumbar puncture demonstrating a WBC count of 8 with 113 copies/mL of HHV-6. Serum levels were also elevated to 4.7 million c/mL. The patient was restarted on foscarnet but continued to deteriorate clinically. She ultimately experienced multiple seizure-like episodes resulting in a noncommunicative, somnolent state. She was transitioned to hospice care and passed away 2 days after discharge.
Conclusion. Despite the use of recommended medical therapies, the mortality and clinical progression of HHV-6 in immunocompetent adults is still unpredictable. Further studies are needed in this population to provide guidance for clinicians.
Disclosures. All Authors: No reported disclosures