title: An approach for differentiating echovirus 30 and Japanese encephalitis virus infections in acute meningitis/encephalitis: a retrospective study of 103 cases in Vietnam.
abstract: BACKGROUND
  In recent decades, Echovirus 30 (E30) and Japanese encephalitis virus (JEV) have been reported to be the common causative agents of acute meningitis among patients in South East Asia. An E30 outbreak in Vietnam in 2001-2002 gained our interest because the initial clinical diagnosis of infected patients was due to JEV infection. There are few clinical insights regarding E30 cases, and there are no reports comparing E30 and JEV acute meningitis/encephalitis cases based on clinical symptoms and case histories. We therefore aimed to identify reliable clinical methods to differentiate E30 and JEV acute meningitis/encephalitis.
  
  
  METHODS
  A retrospective, cross-sectional study was conducted to compare E30 and JEV acute meningitis/encephalitis cases. We collected and analyzed the clinical records of 43 E30 confirmed cases (E30 group) and 60 JEV confirmed cases (JEV group). Clinical data were compared between the E30 and the JEV groups. Differences of clinical parameters were analyzed by certain statistical tests.
  
  
  RESULTS
  Fever, headache, and vomiting were the most common symptoms in both the E30 and the JEV groups. Combined symptoms of headache and vomiting and the triad of symptoms of fever, headache, and vomiting were observed in more patients in the E30 group (E30 vs. JEV: 19% vs. 0%, p < 0.001; 74% vs. 27%, p < 0.001, respectively). On the other hand, strong neurological symptoms such as seizure (5% vs. 73%, p < 0.001) and altered consciousness (12% vs. 97%, p < 0.001) were manifested primarily in the JEV group. CSF leukocytosis was observed predominantly in the E30 group (80 vs. 18 cells/μL, p = 0.003), whereas decreasing CSF sugar level was observed predominantly in the JEV group (58.7 vs. 46.9 mg/dL, p < 0.001).
  
  
  CONCLUSIONS
  Fever, headache, vomiting, absence of neurological symptoms (seizure, altered consciousness), and presence of CSF leukocytosis are important parameters to consider in differentiating E30 from JEV cases during early infection. Then, proper measures can be adopted immediately to prevent the spread of the disease in the affected areas.
authors.affiliation: Department of Virology, Institute of Tropical Medicine, Nagasaki University, 1-12-4, Sakamoto, 852-8523 Nagasaki, Japan. moritak@nagasaki-u.ac.jp.
authors.forename: Yuki
authors.initials: Y
authors.lastname: Takamatsu
authors.forename: Leo
authors.initials: L
authors.lastname: Uchida
authors.forename: Phan Thi
authors.initials: PT
authors.lastname: Nga
authors.forename: Kenta
authors.initials: K
authors.lastname: Okamoto
authors.forename: Takeshi
authors.initials: T
authors.lastname: Nabeshima
authors.forename: Dang Thi Thu
authors.initials: DT
authors.lastname: Thao
authors.forename: Do Thien
authors.initials: do T
authors.lastname: Hai
authors.forename: Nguyen Thi
authors.initials: NT
authors.lastname: Tuyet
authors.forename: Hoang Minh
authors.initials: HM
authors.lastname: Duc
authors.forename: Le Xuan
authors.initials: le X
authors.lastname: Luat
authors.forename: Futoshi
authors.initials: F
authors.lastname: Hasebe
authors.forename: Kouichi
authors.initials: K
authors.lastname: Morita
mesh_terms: D000293:Adolescent; D002555:Cerebrospinal Fluid / Q000166:cytology; D002648:Child; D002675:Child, Preschool; D015510:Clinical Medicine / Q000379:methods*; D003430:Cross-Sectional Studies; D003937:Diagnosis, Differential; D004664:Encephalitis Virus, Japanese / Q000302:isolation & purification*; D018792:Encephalitis, Viral / Q000175:diagnosis* / Q000473:pathology* / Q000821:virology; D029822:Enterovirus B, Human / Q000302:isolation & purification*; D005260:Female; D006261:Headache / Q000209:etiology; D006801:Humans; D007223:Infant; D007964:Leukocytosis / Q000209:etiology; D008297:Male; D008587:Meningitis, Viral / Q000175:diagnosis* / Q000473:pathology* / Q000821:virology; D009422:Nervous System Diseases / Q000209:etiology; D012189:Retrospective Studies; D014744:Vietnam; D014839:Vomiting / Q000209:etiology; D055815:Young Adult
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