title: Hospital-based surveillance for Lassa fever in Edo State, Nigeria, 2005-2008.
abstract: OBJECTIVE
  To estimate the burden of Lassa fever in northern and central Edo, a state in south Nigeria where Lassa fever has been reported.
  
  
  METHODS
  Blood samples were obtained from 60 patients hospitalised at the Irrua Specialist Teaching Hospital (ISTH), Irrua, with a clinical suspicion of Lassa fever and from 451 febrile outpatients seen at the ISTH and hospitals in Ekpoma, Iruekpen, Uromi, Auchi and Igarra. All samples were tested retrospectively by Lassa virus-specific RT-PCR. Outpatients were additionally screened for Lassa virus-specific antibodies by indirect immunofluorescent antibody assay.
  
  
  RESULTS
  Lassa virus was detected in 25 of 60 (42%) patients with a clinical suspicion of Lassa fever. The disease affected persons of all age groups and with various occupations, including healthcare workers. The clinical picture was dominated by gastrointestinal symptoms. The case fatality rate was 29%. Lassa virus was detected in 2 of 451 (0.44%) febrile outpatients, and 8 (1.8%) were positive for Lassa virus-specific IgG.
  
  
  CONCLUSIONS
  Lassa fever contributes to hospital mortality in Edo State. The low prevalence of the disease among outpatients and the low seroprevalence may indicate that the population-level incidence is not high. Surveillance for Lassa fever should focus on the hospitalised patient.
authors.affiliation: Department of Medical Microbiology and Parasitology, College of Medicine, University of Lagos, Lagos, Nigeria.
authors.forename: Deborah U
authors.initials: DU
authors.lastname: Ehichioya
authors.forename: Danny A
authors.initials: DA
authors.lastname: Asogun
authors.forename: Jacqueline
authors.initials: J
authors.lastname: Ehimuan
authors.forename: Peter O
authors.initials: PO
authors.lastname: Okokhere
authors.forename: Meike
authors.initials: M
authors.lastname: Pahlmann
authors.forename: Stephan
authors.initials: S
authors.lastname: Olschläger
authors.forename: Beate
authors.initials: B
authors.lastname: Becker-Ziaja
authors.forename: Stephan
authors.initials: S
authors.lastname: Günther
authors.forename: Sunday A
authors.initials: SA
authors.lastname: Omilabu
mesh_terms: D000293:Adolescent; D000328:Adult; D000914:Antibodies, Viral; D002648:Child; D002675:Child, Preschool; D005260:Female; D019084:Fluorescent Antibody Technique, Indirect; D006784:Hospitals, Teaching / Q000706:statistics & numerical data*; D006801:Humans; D015994:Incidence; D007223:Infant; D007835:Lassa Fever / Q000453:epidemiology* / Q000235:genetics / Q000401:mortality; D008297:Male; D008875:Middle Aged; D009549:Nigeria / Q000453:epidemiology; D015995:Prevalence; D012367:RNA, Viral / Q000032:analysis; D012189:Retrospective Studies; D012959:Socioeconomic Factors; D055815:Young Adult
chemical_list: D000914:Antibodies, Viral; D012367:RNA, Viral