Dying From Dengue Encephalitis in the Absence of DHF: A Case Report.

Background: Dengue fever is an endemic infectious disease in tropical countries including Sri Lanka with a seasonal transmission. Expanded dengue syndrome consists of unusual manifestations of dengue involving the liver, heart, kidney, and central nervous system. Dengue encephalitis is a rare neurological manifestation of expanded dengue syndrome which can lead to significant morbidity and mortality. Among patients with dengue encephalitis, rapid deterioration without plasma leakage and preceding neurological symptoms and signs is an unusual presentation. Case Presentation: We report an 18-year-old previously healthy male, who presented with fever for three days with mild frontal headache without other preceding neurological signs who succumbed following rapid deterioration and generalized tonic-clonic seizures complicated with status epilepticus despite optimal medical management. He did not have features of plasma leakage clinically and through focused ultrasound and did not have rising pack cell volume. He was positive for dengue NS1, IgM, and RT-PCR for dengue Serotype 3 with histopathological findings of the brain revealing dengue encephalitis. Conclusions: Dengue encephalitis can lead to sudden and unexpected mortality associated with status epilepticus with or without signs of dengue hemorrhagic fever. It is a rare manifestation seen in dengue expanded syndrome and can cause sudden death without warning symptoms and signs. The initial presentation may have little warning signs without obvious neurological signs; hence, it is imperative to be vigilant on atypical but potentially lethal presentations of dengue fever.