Neurological manifestations of dengue infection

Background Severe forms of dengue, the most important arboviral infection o f man, are associated with haemorrhagic disease and a generalised Vascular leak syndrome. The importance of dengue as a cause of neurological disease is uncertain. Methods During 1995, all patients with suspected CNS infections admitted to a referral hospital in southern Vietnam were investigated by culture, PCR, and antibody measurement in serum and CSF for dengue and other viruses. Findings Of 378 patients, 16 (4.2%) were infected with dengue viruses, comp ared with four (1.4%) of 286 hospital controls (odds ratio [95% CI] 3.1[1.7 -5.8]). Five additional dengue positive patients with CNS abnormalities wer e studied subsequently. No other cause of CNS infection was identified. Sev en infections were primary dengue, 13 secondary, and one was not classified . Ten patients had dengue viruses isolated or detected by PCR, and three ha d dengue antibody in the CSF. 12 of the 21 had no characteristic features o f dengue on admission. The most frequent neurological manifestations were r educed consciousness and convulsions. Nine patients had encephalitis. No pa tient died, but six had neurological sequelae at discharge. Phylogenetic an alysis of the four DEN-2 strains isolated mapped them with a DEN-2 strain i solated from a patient with dengue haemorhagic fever, and with other strain s previously isolated in southern Vietnam. Interpretation In dengue endemic areas patients with encephalitis and encep halopathy should be investigated for this infection, whether or not they ha ve other features of the disease.