“Locked in a cage”—A case of dengue virus 4 encephalitis


A 62-year-old Chinese woman was admitted to the hospital with a four-day history of fever associated with chills, rigors, and headache. She also complained of postural giddiness, five episodes of vomiting, and shortness of breath on exertion for one day. She denied any abdominal pain or bleeding manifestations. Her past medical history was unremarkable, and she had not travelled out of Singapore. Clinical evaluation revealed tympanic temperature of 38.2 ̊C, blood pressure of 140/80 mmHg, and pulse rate of 92 beats per minute. The patient was alert and orientated with a Glasgow Coma Score (GCS) of 15. She had a faint maculopapular rash, but physical examination was otherwise unremarkable; the lungs were clear to auscultation, and there was no abdominal tenderness or hepatomegaly. Hematology and biochemistry results on admission are summarised in Table 1. Chest radiograph was normal, with no radiographic evidence of pleural effusion. Serum dengue NS1 antigen was positive, and dengue IgM and IgG were negative (SD BIOLINE Dengue Duo Cassette, Alere). During the initial two days of her admission, the patient did not develop any further dengue warning signs, such as abdominal pain, hepatomegaly, persistent vomiting, or bleeding manifestations. Her platelet count nadir was 62 x 10/L (day 5 of illness). She developed confusion and receptive and expressive aphasia with inability to recognize her family members on day 6 of illness. On examination, she was afebrile, GCS was E4V2M5, and there were no signs of meningism. Apart from the receptive and expressive aphasia, a full neurological examination did not reveal any motor or sensory deficit. A computed tomography scan of the brain that day showed no acute cerebral infarct or hemorrhage. Her hematocrit had risen by 6.8% but did not fulfil criteria for significant hemoconcentration; thrombocytopenia was mild, and although transaminitis was worse, it rapidly improved (shown in Table 1). Workup for nosocomial infection comprising blood cultures and urinalysis was unrevealing. Cerebrospinal fluid (CSF) analysis revealed a nucleated cell count of 62 cells/uL (97% lymphocytes, 2% macrophages, 1% neutrophils), an erythrocyte count of 9 cells/uL, a protein count of 2.33 g/L, and a glucose count of 3.5 mmol/L (serum glucose 5.9 mmol/L). CSF Gram stain and culture, tetraplex polymerase chain (PCR) testing for Cytomegalovirus, herpes simplex virus (HSV), varicella zoster virus (VZV), and Toxoplasma gondii were negative. CSF enterovirus PCR testing was negative, as were tests for CSF measles and mumps serology. We proceeded to do magnetic resonance imaging (MRI) of the brain and angiography with contrast the next day (day 7 of illness and day 2 of confusion) due to the persistent confusion with aphasia. There was no evidence of restricted diffusion or abnormal susceptibility, with no focal abnormal signals in

DOI: 10.1371/journal.pntd.0005369

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Cite this paper

@inproceedings{Ng2017LockedIA, title={“Locked in a cage”—A case of dengue virus 4 encephalitis}, author={Deborah H L Ng and Sapna Sadarangani}, booktitle={PLoS neglected tropical diseases}, year={2017} }