|Year : 2015 | Volume
| Issue : 1 | Page : 62-63
Amit A Bharadiya1, Jyotsna B Jaju2, Swati C Aundhakar1, Makarand Mane1, Vikrant Mahajani1
1 Department of Medicine, Krishna Institute of Medical Sciences and Research Centre, Karad, Maharashtra, India
2 Department of Biochemistry, Swami Ramanand Teerth Rural Medical College, Ambajogai, Maharashtra, India
|Date of Web Publication||8-Dec-2014|
Amit A Bharadiya
Medicine Resident, Room No. 102, IHR, Krishna Institute of Medical Sciences, Karad - 415 110, Maharashtra
Source of Support: None, Conflict of Interest: None
Presentation of dengue fever can range from asymptomatic infection to life-threatening dengue hemorrhagic fever and dengue shock syndrome. We report a case of dengue fever presenting as encephalitis, which is very rare.
Keywords: Dengue encephalitis, dengue fever, dengue hemorrhagic fever, dengue shock syndrome, encephalitis
|How to cite this article:|
Bharadiya AA, Jaju JB, Aundhakar SC, Mane M, Mahajani V. Dengue encephalitis. Muller J Med Sci Res 2015;6:62-3
| Introduction|| |
Dengue is an arboviral infection common in tropical countries including South and Southeast Asia. Fever, arthralgia, headache, petechial spots, rash, and hemorrhagic manifestations are common features. Encephalopathy and neurological complications are well reported, but poorly understood. However, there is increasing evidence for dengue viral neurotropism suggesting there may be an element of direct encephalitis in some dengue patients.
| Case Report|| |
A 45-year-old male patient was brought to our hospital with the complaints of fever and headache since 3 days and altered consciousness since 2-3 h. Fever was continuous and moderate in nature without chills or rigors. Retro-orbital headache was present. There was a sudden-onset alteration in consciousness of the patient. There was no history of vomiting, bleeding from any site, convulsions, or head trauma. Past history was not contributory.
On general examination, patient was disoriented and very tachypneic. He was in shock as his pulse was feeble and blood pressure could not be recorded. His extremities were cold and he had ptosis of his left eye. There was no rash, pallor, icterus, cyanosis, lymphadenopathy, or pedal edema.
On central nervous system (CNS) examination, he was conscious and disoriented with a Glasgow coma scale score of 11 out of 15 at admission. He had neck stiffness, Kernig's sign was positive, and deep tendon reflexes were normal. He also had ankle clonus. On respiratory system examination, breath sounds were heard equally on both sides of the chest. Bilateral conducted sounds were also heard. On cardiovascular system examination, heart sounds were normal and there was no murmur. Per abdomen examination revealed no tenderness or any organomegaly.
He required immediate intubation and mechanical ventilation with fluid resuscitation. Meropenam 1 g 8 hourly was given keeping the possibility of bacterial meningitis in mind and also to cover aspiration.
Investigations revealed hemoglobin of 14.3 gm%, leukocyte count of 7000, and 60,000 platelets. Packed cell volume was 45%. Peripheral smear did not reveal any malarial parasite. Rapid test for malarial antigen was negative. Dengue IgM was positive and as it was done from a reputed laboratory, the chances of it being false positive were nil or very low. Nonstructural protein 1 (NS1) antigen test was positive. Cerebrospinal fluid (CSF) studies showed 25 cells/mm 3 and all were lymphocytes; protein was 106 mg/dl. Gram stain and Ziehl-Neelsen stain were negative. CSF and blood cultures were sterile. CSF tuberculosis polymerase chain reaction (TB-PCR) could not detect any mycobacterial DNA. A chest X-ray showed a right-sided pleural effusion and bilateral infiltrates suggesting aspiration. Ultrasonography of abdomen was normal.
The patient was weaned off mechanical ventilation by day 3 and a magnetic resonance imaging (MRI) brain was done [Figure 1]. It was suggestive of encephalitis. CSF enzyme-linked immunosorbent assay (ELISA) for Japanese and herpes encephalitis was both negative. A diagnosis of dengue shock syndrome with encephalitis was made. The patient recovered completely with supportive treatment in the form of intravenous fluids and broad-spectrum antibiotic coverage with injection meropenam 1 g given intravenously every 12 h for 2 weeks. He was neither given any antiviral drugs nor any blood component transfusion. He was discharged after 2 weeks of hospitalization.
| Discussion|| |
Dengue fever is a viral infection transmitted in urban areas by Aedes aegypti. The virus has four serotypes; DEN-1 to DEN-4. Any virus serotype may be involved, but DEN-2 and DEN-3 are most frequently reported as the cause of severe neurological disease.  Involvement of the CNS in dengue fever and dengue hemorrhagic fever has always been thought to be secondary to vasculitis, with resultant fluid extravasation, cerebral edema, hypoperfusion, hyponatremia, liver failure, and/or renal failure. Reports of virus isolation from brain tissue and CSF of patients with neurological symptoms suggest direct virus invasion of the CNS. , However, viral serotyping could not be done in our patient due to non-availability.
Dengue virus mainly replicates in the cells of macrophage line; infiltration of virus-infected macrophages into the brain is one pathway of entry into the brain in dengue encephalitis. 
Encephalitis typically presents with fever, headache, reduced consciousness, seizures, and focal neurological signs. Numerous neurological manifestations that have been reported are: Encephalopathy (the most common), Guillain-Barre syndrome,  myositis,  transverse myelitis,  and acute disseminated encephalomyelitis.  Encephalopathy is reduced consciousness occurring commonly due to infections, metabolic derangements, alcohol, or drugs  and uncommonly due to encephalitis. Hepatic encephalopathy is well reported in dengue.  Even after careful exclusion of patients of encephalopathy due to known causes, a subset of patient remains. Hence, dengue encephalitis may be a distinct entity. No specific antiviral treatment exists for dengue encephalitis like that of other viral encephalitis (herpes simplex virus/Japanese encephalitis). General supportive and symptomatic treatment remains the basis of management. The disease appears to be self-limiting.
| Conclusion|| |
Our patient had encephalitis, most likely secondary to dengue. Due to its rising incidence, Dengue encephalitis can be considered as a separate entity and an addition to the clinical spectrum of dengue fever. Increasing recognition of this condition and further research is necessary for detailed understanding of the spectrum of dengue fever.
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