title: Review of the etiologies of viral meningitis and encephalitis in a dengue endemic region.
abstract: OBJECTIVE
  To evaluate the etiology of viral meningitis and encephalitis in adults and adolescents living in areas affected by dengue.
  
  
  METHODS
  Over two years, adults and adolescents with diagnoses of viral encephalitis or meningitis were selected for study in Brazil. PCRs for dengue, enterovirus, HSV1 and 2 and cytomegalovirus were performed in CSF samples. Serum and CSF samples were tested for the presence of anti-dengue IgM antibodies.
  
  
  RESULTS
  The etiologies of encephalitis and meningitis were determined in 70% of cases (30/47). Dengue was the leading cause of encephalitis (47%) with normal CSF cellularity in 75% of these patients. HSV1 was found in 17.6% of the cases, two of which had mild encephalitis. Enterovirus was the most common cause of meningitis (50%), followed by HSV1 (15%), cytomegalovirus and dengue (10%, each).
  
  
  CONCLUSIONS
  We identified the viral agents causing encephalitis and meningitis in a higher proportion of cases than has been reported in other studies. Dengue was the most frequent cause of encephalitis, which surpassed HSV. In endemic areas, dengue should be investigated as an important cause of encephalitis. Normal CSF cellularity should not exclude dengue encephalitis. Enterovirus is known to be the leading cause of meningitis in children, but here we found it was also the main cause of the disease in adults. HSV1 should be investigated in patients with mild forms of encephalitis and meningitis.
authors.affiliation: Neurology Service, Antônio Pedro Hospital/Federal Fluminense University, Brazil. cnsoares@predialnet.com.br
authors.forename: Cristiane N
authors.initials: CN
authors.lastname: Soares
authors.forename: Mauro J
authors.initials: MJ
authors.lastname: Cabral-Castro
authors.forename: José M
authors.initials: JM
authors.lastname: Peralta
authors.forename: Marcos R G
authors.initials: MR
authors.lastname: de Freitas
authors.forename: Mariano
authors.initials: M
authors.lastname: Zalis
authors.forename: Marzia
authors.initials: M
authors.lastname: Puccioni-Sohler
mesh_terms: D000293:Adolescent; D000328:Adult; D000914:Antibodies, Viral / Q000032:analysis; D001938:Brazil / Q000453:epidemiology; D002648:Child; D003587:Cytomegalovirus / Q000235:genetics; D003715:Dengue / Q000453:epidemiology*; D003716:Dengue Virus / Q000235:genetics; D018792:Encephalitis, Viral / Q000453:epidemiology* / Q000209:etiology* / Q000821:virology; D005260:Female; D018259:Herpesvirus 1, Human; D006801:Humans; D008297:Male; D008587:Meningitis, Viral / Q000453:epidemiology* / Q000209:etiology* / Q000821:virology; D008875:Middle Aged; D011446:Prospective Studies; D012367:RNA, Viral / Q000032:analysis / Q000235:genetics; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013129:Spinal Puncture; D055815:Young Adult
chemical_list: D000914:Antibodies, Viral; D012367:RNA, Viral